<html lang="en"> <head> <title>GNU Libidn</title> <meta http-equiv="Content-Type" content="text/html"> <meta name="description" content="GNU Libidn"> <meta name="generator" content="makeinfo 4.8"> <link title="Top" rel="top" href="#Top"> <link href="http://www.gnu.org/software/texinfo/" rel="generator-home" title="Texinfo Homepage"> <!-- This manual is last updated 31 May 2007 for version 0.6.14 of GNU Libidn. Copyright (C) 2002, 2003, 2004, 2005, 2006, 2007 Simon Josefsson. Permission is granted to copy, distribute and/or modify this document under the terms of the GNU Free Documentation License, Version 1.2 or any later version published by the Free Software Foundation; with the Invariant Sections being "Commercial Support", no Front-Cover Texts, and no Back-Cover Texts. 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#aaaaff; background: #eeeeff; padding-bottom: 1em; } pre.verbatim { border: solid 1px gray; background: white; padding-bottom: 1em; } div.node { background: #ffeeee; margin: 0 -5% 0 -2%; padding: 0.5em 0.5em; border: solid 1px #ffaaaa; margin-top: 0.5em; margin-bottom: 0.5em; font-weight: bold; color: #770000; } .node a { color: #770000; } .node a:visited { color: #550000; } dd, li { padding-top: 0.1em; padding-bottom: 0.1em; } --></style> </head> <body> <h1 class="settitle">GNU Libidn</h1> <div class="contents"> <h2>Table of Contents</h2> <ul> <li><a name="toc_Top" href="#Top">GNU Libidn</a> <li><a name="toc_Introduction" href="#Introduction">1 Introduction</a> <ul> <li><a href="#Getting-Started">1.1 Getting Started</a> <li><a href="#Features">1.2 Features</a> <li><a href="#Library-Overview">1.3 Library Overview</a> <li><a href="#Supported-Platforms">1.4 Supported Platforms</a> <li><a href="#Getting-help">1.5 Getting help</a> <li><a href="#Commercial-Support">1.6 Commercial Support</a> <li><a href="#Downloading-and-Installing">1.7 Downloading and Installing</a> <li><a href="#Bug-Reports">1.8 Bug Reports</a> <li><a href="#Contributing">1.9 Contributing</a> </li></ul> <li><a name="toc_Preparation" href="#Preparation">2 Preparation</a> <ul> <li><a href="#Header">2.1 Header</a> <li><a href="#Initialization">2.2 Initialization</a> <li><a href="#Version-Check">2.3 Version Check</a> <li><a href="#Building-the-source">2.4 Building the source</a> <li><a href="#Autoconf-tests">2.5 Autoconf tests</a> </li></ul> <li><a name="toc_Utility-Functions" href="#Utility-Functions">3 Utility Functions</a> <ul> <li><a href="#Utility-Functions">3.1 Header file <code>stringprep.h</code></a> <li><a href="#Utility-Functions">3.2 Unicode Encoding Transformation</a> <li><a href="#Utility-Functions">3.3 Unicode Normalization</a> <li><a href="#Utility-Functions">3.4 Character Set Conversion</a> </li></ul> <li><a name="toc_Stringprep-Functions" href="#Stringprep-Functions">4 Stringprep Functions</a> <ul> <li><a href="#Stringprep-Functions">4.1 Header file <code>stringprep.h</code></a> <li><a href="#Stringprep-Functions">4.2 Defining A Stringprep Profile</a> <li><a href="#Stringprep-Functions">4.3 Control Flags</a> <li><a href="#Stringprep-Functions">4.4 Core Functions</a> <li><a href="#Stringprep-Functions">4.5 Error Handling</a> <li><a href="#Stringprep-Functions">4.6 Stringprep Profile Macros</a> </li></ul> <li><a name="toc_Punycode-Functions" href="#Punycode-Functions">5 Punycode Functions</a> <ul> <li><a href="#Punycode-Functions">5.1 Header file <code>punycode.h</code></a> <li><a href="#Punycode-Functions">5.2 Unicode Code Point Data Type</a> <li><a href="#Punycode-Functions">5.3 Core Functions</a> <li><a href="#Punycode-Functions">5.4 Error Handling</a> </li></ul> <li><a name="toc_IDNA-Functions" href="#IDNA-Functions">6 IDNA Functions</a> <ul> <li><a href="#IDNA-Functions">6.1 Header file <code>idna.h</code></a> <li><a href="#IDNA-Functions">6.2 Control Flags</a> <li><a href="#IDNA-Functions">6.3 Prefix String</a> <li><a href="#IDNA-Functions">6.4 Core Functions</a> <li><a href="#IDNA-Functions">6.5 Simplified ToASCII Interface</a> <li><a href="#IDNA-Functions">6.6 Simplified ToUnicode Interface</a> <li><a href="#IDNA-Functions">6.7 Error Handling</a> </li></ul> <li><a name="toc_TLD-Functions" href="#TLD-Functions">7 TLD Functions</a> <ul> <li><a href="#TLD-Functions">7.1 Header file <code>tld.h</code></a> <li><a href="#TLD-Functions">7.2 Core Functions</a> <li><a href="#TLD-Functions">7.3 Utility Functions</a> <li><a href="#TLD-Functions">7.4 High-Level Wrapper Functions</a> <li><a href="#TLD-Functions">7.5 Error Handling</a> </li></ul> <li><a name="toc_PR29-Functions" href="#PR29-Functions">8 PR29 Functions</a> <ul> <li><a href="#PR29-Functions">8.1 Header file <code>pr29.h</code></a> <li><a href="#PR29-Functions">8.2 Core Functions</a> <li><a href="#PR29-Functions">8.3 Utility Functions</a> <li><a href="#PR29-Functions">8.4 Error Handling</a> </li></ul> <li><a name="toc_Examples" href="#Examples">9 Examples</a> <ul> <li><a href="#Example-1">9.1 Example 1</a> <li><a href="#Example-2">9.2 Example 2</a> <li><a href="#Example-3">9.3 Example 3</a> <li><a href="#Example-4">9.4 Example 4</a> <li><a href="#Example-5">9.5 Example 5</a> </li></ul> <li><a name="toc_Invoking-idn" href="#Invoking-idn">10 Invoking idn</a> <ul> <li><a href="#Invoking-idn">10.1 Name</a> <li><a href="#Invoking-idn">10.2 Description</a> <li><a href="#Invoking-idn">10.3 Options</a> <li><a href="#Invoking-idn">10.4 Environment Variables</a> <li><a href="#Invoking-idn">10.5 Examples</a> <li><a href="#Invoking-idn">10.6 Troubleshooting</a> </li></ul> <li><a name="toc_Emacs-API" href="#Emacs-API">11 Emacs API</a> <ul> <li><a href="#Emacs-API">11.1 Punycode Emacs API</a> <li><a href="#Emacs-API">11.2 IDNA Emacs API</a> </li></ul> <li><a name="toc_Java-API" href="#Java-API">12 Java API</a> <ul> <li><a href="#Java-API">12.1 Overview</a> <li><a href="#Java-API">12.2 Miscellaneous Programs</a> <ul> <li><a href="#Java-API">12.2.1 GenerateRFC3454</a> <li><a href="#Java-API">12.2.2 GenerateNFKC</a> <li><a href="#Java-API">12.2.3 TestIDNA</a> <li><a href="#Java-API">12.2.4 TestNFKC</a> </li></ul> <li><a href="#Java-API">12.3 Possible Problems</a> <li><a href="#Java-API">12.4 A Note on Java and Unicode</a> </li></ul> <li><a name="toc_C_0023-API" href="#C_0023-API">13 C# API</a> <li><a name="toc_Acknowledgements" href="#Acknowledgements">14 Acknowledgements</a> <li><a name="toc_History" href="#History">15 History</a> <li><a name="toc_PR29-discussion" href="#PR29-discussion">Appendix A PR29 discussion</a> <li><a name="toc_Copying-Information" href="#Copying-Information">Appendix B Copying Information</a> <ul> <li><a href="#GNU-Free-Documentation-License">B.1 GNU Free Documentation License</a> <li><a href="#GNU-LGPL">B.2 GNU Lesser General Public License</a> <li><a href="#GNU-GPL">B.3 GNU General Public License</a> </li></ul> <li><a name="toc_Function-and-Variable-Index" href="#Function-and-Variable-Index">Function and Variable Index</a> <li><a name="toc_Concept-Index" href="#Concept-Index">Concept Index</a> </li></ul> </div> <div class="node"> <p><hr> <a name="Top"></a> Next: <a rel="next" accesskey="n" href="#Introduction">Introduction</a>, Up: <a rel="up" accesskey="u" href="#dir">(dir)</a> </div> <h2 class="unnumbered">GNU Libidn</h2> <p>This manual is last updated 31 May 2007 for version 0.6.14 of GNU Libidn. <p>Copyright © 2002, 2003, 2004, 2005, 2006, 2007 Simon Josefsson. <blockquote> Permission is granted to copy, distribute and/or modify this document under the terms of the GNU Free Documentation License, Version 1.2 or any later version published by the Free Software Foundation; with the Invariant Sections being “Commercial Support”, no Front-Cover Texts, and no Back-Cover Texts. A copy of the license is included in the section entitled “GNU Free Documentation License”. </blockquote> <ul class="menu"> <li><a accesskey="1" href="#Introduction">Introduction</a>: How to use this manual. <li><a accesskey="2" href="#Preparation">Preparation</a>: What you should do before using the library. <li><a accesskey="3" href="#Utility-Functions">Utility Functions</a>: Unicode transformation utility functions. <li><a accesskey="4" href="#Stringprep-Functions">Stringprep Functions</a>: Stringprep functions. <li><a accesskey="5" href="#Punycode-Functions">Punycode Functions</a>: Punycode functions. <li><a accesskey="6" href="#IDNA-Functions">IDNA Functions</a>: IDNA functions. <li><a accesskey="7" href="#TLD-Functions">TLD Functions</a>: TLD functions. <li><a accesskey="8" href="#PR29-Functions">PR29 Functions</a>: Detect strings non-idempotent under NFKC. <li><a accesskey="9" href="#Examples">Examples</a>: Demonstrate how to use the library. <li><a href="#Invoking-idn">Invoking idn</a>: Command line interface to the library. <li><a href="#Emacs-API">Emacs API</a>: Emacs Lisp API for Libidn. <li><a href="#Java-API">Java API</a>: Notes on the Java port of Libidn. <li><a href="#C_0023-API">C# API</a>: Notes on the C# port of Libidn. <li><a href="#Acknowledgements">Acknowledgements</a>: Whom to blame. <li><a href="#History">History</a>: Rough outline of development history. </li></ul> <p>Appendices </p> <ul class="menu"> <li><a href="#PR29-discussion">PR29 discussion</a>: Implementation aspects of the PR29 flaw. <li><a href="#Copying-Information">Copying Information</a>: License text covering the Libidn library. </li></ul> <p>Indices </p> <ul class="menu"> <li><a href="#Function-and-Variable-Index">Function and Variable Index</a> <li><a href="#Concept-Index">Concept Index</a> </ul> <div class="node"> <p><hr> <a name="Introduction"></a> Next: <a rel="next" accesskey="n" href="#Preparation">Preparation</a>, Previous: <a rel="previous" accesskey="p" href="#Top">Top</a>, Up: <a rel="up" accesskey="u" href="#Top">Top</a> </div> <h2 class="chapter">1 Introduction</h2> <p>GNU Libidn is an implementation of the Stringprep, Punycode and IDNA specifications defined by the IETF Internationalized Domain Names (IDN) working group, used for internationalized domain names. The C library is available under the GNU Lesser General Public License (see <a href="#GNU-LGPL">GNU LGPL</a>). <p>The library contains a generic Stringprep implementation that does Unicode 3.2 NFKC normalization, mapping and prohibitation of characters, and bidirectional character handling. Profiles for Nameprep, iSCSI, SASL and XMPP are included. Punycode and ASCII Compatible Encoding (ACE) via IDNA are supported. A mechanism to define Top-Level Domain (TLD) specific validation tables, and to compare strings against those tables, is included. Default tables for some TLDs are also included. <p>The Stringprep API consists of two main functions, one for converting data from the system's native representation into UTF-8, and one function to perform the Stringprep processing. Adding a new Stringprep profile for your application within the API is straightforward. The Punycode API consists of one encoding function and one decoding function. The IDNA API consists of the ToASCII and ToUnicode functions, as well as an high-level interface for converting entire domain names to and from the ACE encoded form. The TLD API consists of one set of functions to extract the TLD name from a domain string, one set of functions to locate the proper TLD table to use based on the TLD name, and core functions to validate a string against a TLD table, and some utility wrappers to perform all the steps in one call. <p>The library is used by, e.g., GNU SASL and Shishi to process user names and passwords. Libidn can be built into GNU Libc to enable a new system-wide getaddrinfo flag for IDN processing. <p>Libidn is developed for the GNU/Linux system, but runs on over 20 Unix platforms (including Solaris, IRIX, AIX, and Tru64) and Windows. Libidn is written in C and (parts of) the API is accessible from C, C++, Emacs Lisp, Python and Java. A native Java and C# port is also provided, licensed under the GNU Lesser General Public License (see <a href="#GNU-LGPL">GNU LGPL</a>). <ul class="menu"> <li><a accesskey="1" href="#Getting-Started">Getting Started</a> <li><a accesskey="2" href="#Features">Features</a> <li><a accesskey="3" href="#Library-Overview">Library Overview</a> <li><a accesskey="4" href="#Supported-Platforms">Supported Platforms</a> <li><a accesskey="5" href="#Getting-help">Getting help</a> <li><a accesskey="6" href="#Commercial-Support">Commercial Support</a> <li><a accesskey="7" href="#Downloading-and-Installing">Downloading and Installing</a> <li><a accesskey="8" href="#Bug-Reports">Bug Reports</a> <li><a accesskey="9" href="#Contributing">Contributing</a> </ul> <div class="node"> <p><hr> <a name="Getting-Started"></a> Next: <a rel="next" accesskey="n" href="#Features">Features</a>, Up: <a rel="up" accesskey="u" href="#Introduction">Introduction</a> </div> <h3 class="section">1.1 Getting Started</h3> <p>This manual documents the library programming interface. All functions and data types provided by the library are explained. Included are also examples, and documentation for the command line tool <samp><span class="file">idn</span></samp> that provide a quick interface to the library. The Emacs Lisp bindings for the library is also discussed. <p>The reader is assumed to possess basic familiarity with internationalization concepts and network programming in C or C++. <p>This manual can be used in several ways. If read from the beginning to the end, it gives a good introduction into the library and how it can be used in an application. Forward references are included where necessary. Later on, the manual can be used as a reference manual to get just the information needed about any particular interface of the library. Experienced programmers might want to start looking at the examples at the end of the manual (see <a href="#Examples">Examples</a>), and then only read up those parts of the interface which are unclear. <div class="node"> <p><hr> <a name="Features"></a> Next: <a rel="next" accesskey="n" href="#Library-Overview">Library Overview</a>, Previous: <a rel="previous" accesskey="p" href="#Getting-Started">Getting Started</a>, Up: <a rel="up" accesskey="u" href="#Introduction">Introduction</a> </div> <h3 class="section">1.2 Features</h3> <p>This library might have a couple of advantages over other libraries doing a similar job. <dl> <dt>It's Free Software<dd>Anybody can use, modify, and redistribute it under the terms of the GNU Lesser General Public License (see <a href="#GNU-LGPL">GNU LGPL</a>). <br><dt>It's thread-safe<dd>No global state is kept in the library. All functions are reentrant. <br><dt>It's portable<dd>The code is intended to be written in pure ANSI C89. It has been tested on many Unix like operating systems, and Windows. <br><dt>It's modularized<dd>The library is composed of several modules, and the only interaction between modules is through each modules' public API. If you only need one piece of functionality, it is possible to take the files you need and incorporate them into your own project. <br><dt>It's not bloated<dd>The design of the library is based on the smallest API necessary to implement the basic functionality. It has been carefully extended with a small number of high-level wrappers to make it comfortable to use the library. However, it does not implement additional functionality just for the sake of completeness. <br><dt>It's documented<dd>Sadly, not all software comes with documentation these days. This one does. </dl> <div class="node"> <p><hr> <a name="Library-Overview"></a> Next: <a rel="next" accesskey="n" href="#Supported-Platforms">Supported Platforms</a>, Previous: <a rel="previous" accesskey="p" href="#Features">Features</a>, Up: <a rel="up" accesskey="u" href="#Introduction">Introduction</a> </div> <h3 class="section">1.3 Library Overview</h3> <p>The following illustration show the components that make up Libidn, and how your application relates to the library. In the illustration, various components are shown as boxes. You see the generic StringPrep component, the various StringPrep profiles including Nameprep, the Punycode component, the IDNA component, and the TLD component. The arrows indicate aggregation, e.g., IDNA uses Punycode and Nameprep, and in turn Nameprep uses the generic StringPrep interface. The interfaces to all components are available for applications, no component within the library is hidden from the application. <div class="block-image"><img src="libidn-components.png" alt="libidn-components.png"></div> <div class="node"> <p><hr> <a name="Supported-Platforms"></a> Next: <a rel="next" accesskey="n" href="#Getting-help">Getting help</a>, Previous: <a rel="previous" accesskey="p" href="#Library-Overview">Library Overview</a>, Up: <a rel="up" accesskey="u" href="#Introduction">Introduction</a> </div> <h3 class="section">1.4 Supported Platforms</h3> <p>Libidn has at some point in time been tested on the following platforms. <ol type=1 start=1> <li>Debian GNU/Linux 3.0 (Woody) <a name="index-Debian-1"></a> GCC 2.95.4 and GNU Make. This is the main development platform. <code>alphaev67-unknown-linux-gnu</code>, <code>alphaev6-unknown-linux-gnu</code>, <code>arm-unknown-linux-gnu</code>, <code>armv4l-unknown-linux-gnu</code>, <code>hppa-unknown-linux-gnu</code>, <code>hppa64-unknown-linux-gnu</code>, <code>i686-pc-linux-gnu</code>, <code>ia64-unknown-linux-gnu</code>, <code>m68k-unknown-linux-gnu</code>, <code>mips-unknown-linux-gnu</code>, <code>mipsel-unknown-linux-gnu</code>, <code>powerpc-unknown-linux-gnu</code>, <code>s390-ibm-linux-gnu</code>, <code>sparc-unknown-linux-gnu</code>, <code>sparc64-unknown-linux-gnu</code>. <li>Debian GNU/Linux 2.1 <a name="index-Debian-2"></a> GCC 2.95.1 and GNU Make. <code>armv4l-unknown-linux-gnu</code>. <li>Tru64 UNIX <a name="index-Tru64-3"></a> Tru64 UNIX C compiler and Tru64 Make. <code>alphaev67-dec-osf5.1</code>, <code>alphaev68-dec-osf5.1</code>. <li>SuSE Linux 7.1 <a name="index-SuSE-4"></a> GCC 2.96 and GNU Make. <code>alphaev6-unknown-linux-gnu</code>, <code>alphaev67-unknown-linux-gnu</code>. <li>SuSE Linux 7.2a <a name="index-SuSE-Linux-5"></a> GCC 3.0 and GNU Make. <code>ia64-unknown-linux-gnu</code>. <li>SuSE Linux <a name="index-SuSE-Linux-6"></a> GCC 3.2.2 and GNU Make. <code>x86_64-unknown-linux-gnu</code> (AMD64 Opteron “Melody”). <li>SuSE Enterprise Server 9 on IBM OpenPower 720 <a name="index-SuSE-Linux-7"></a><a name="index-OpenPower-720-8"></a> GCC 3.3.3 and GNU Make. <code>powerpc64-unknown-linux-gnu</code>. <li>RedHat Linux 7.2 <a name="index-RedHat-9"></a> GCC 2.96 and GNU Make. <code>alphaev6-unknown-linux-gnu</code>, <code>alphaev67-unknown-linux-gnu</code>, <code>ia64-unknown-linux-gnu</code>. <li>RedHat Linux 8.0 <a name="index-RedHat-10"></a> GCC 3.2 and GNU Make. <code>i686-pc-linux-gnu</code>. <li>RedHat Advanced Server 2.1 <a name="index-RedHat-Advanced-Server-11"></a> GCC 2.96 and GNU Make. <code>i686-pc-linux-gnu</code>. <li>Slackware Linux 8.0.01 <a name="index-RedHat-12"></a> GCC 2.95.3 and GNU Make. <code>i686-pc-linux-gnu</code>. <li>Mandrake Linux 9.0 <a name="index-Mandrake-13"></a> GCC 3.2 and GNU Make. <code>i686-pc-linux-gnu</code>. <li>IRIX 6.5 <a name="index-IRIX-14"></a> MIPS C compiler, IRIX Make. <code>mips-sgi-irix6.5</code>. <li>AIX 4.3.2 <a name="index-AIX-15"></a> IBM C for AIX compiler, AIX Make. <code>rs6000-ibm-aix4.3.2.0</code>. <li>Microsoft Windows 2000 (Cygwin) <a name="index-Windows-16"></a> GCC 3.2, GNU make. <code>i686-pc-cygwin</code>. <li>HP-UX 11 <a name="index-HP_002dUX-17"></a> HP-UX C compiler and HP Make. <code>ia64-hp-hpux11.22</code>, <code>hppa2.0w-hp-hpux11.11</code>. <li>SUN Solaris 2.7 <a name="index-Solaris-18"></a> GCC 3.0.4 and GNU Make. <code>sparc-sun-solaris2.7</code>. <li>SUN Solaris 2.8 <a name="index-Solaris-19"></a> Sun WorkShop Compiler C 6.0 and SUN Make. <code>sparc-sun-solaris2.8</code>. <li>SUN Solaris 2.9 <a name="index-Solaris-20"></a> Sun Forte Developer 7 C compiler and GNU Make. <code>sparc-sun-solaris2.9</code>. <li>NetBSD 1.6 <a name="index-NetBSD-21"></a> GCC 2.95.3 and GNU Make. <code>alpha-unknown-netbsd1.6</code>, <code>i386-unknown-netbsdelf1.6</code>. <li>OpenBSD 3.1 and 3.2 <a name="index-OpenBSD-22"></a> GCC 2.95.3 and GNU Make. <code>alpha-unknown-openbsd3.1</code>, <code>i386-unknown-openbsd3.1</code>. <li>FreeBSD 4.7 and 4.8 <a name="index-FreeBSD-23"></a> GCC 2.95.4 and GNU Make. <code>alpha-unknown-freebsd4.7</code>, <code>alpha-unknown-freebsd4.8</code>, <code>i386-unknown-freebsd4.7</code>, <code>i386-unknown-freebsd4.8</code>. <li>MacOS X 10.2 Server Edition <a name="index-MacOS-X-24"></a> GCC 3.1 and GNU Make. <code>powerpc-apple-darwin6.5</code>. <li>MacOS X 10.4 “Tiger” with Xcode 2.0 <a name="index-MacOS-X-25"></a> GCC 4.0 and GNU Make. <code>powerpc-apple-darwin8.0</code>. <li>Cross compiled to uClinux/uClibc on Motorola Coldfire <a name="index-Motorola-Coldfire-26"></a><a name="index-uClinux-27"></a><a name="index-uClibc-28"></a> GCC 3.4 and GNU Make <code>m68k-uclinux-elf</code>. <li>Cross compiled to ARM using Glibc <a name="index-ARM-29"></a> GCC 2.95 and GNU Make <code>arm-linux</code>. <li>Cross compiled to Mingw32. <a name="index-Windows-30"></a><a name="index-Microsoft-31"></a><a name="index-mingw32-32"></a> GCC 3.4.4 and GNU Make <code>i586-mingw32msvc</code>. </ol> <p>If you use Libidn on, or port Libidn to, a new platform please report it to the author. <div class="node"> <p><hr> <a name="Getting-help"></a> Next: <a rel="next" accesskey="n" href="#Commercial-Support">Commercial Support</a>, Previous: <a rel="previous" accesskey="p" href="#Supported-Platforms">Supported Platforms</a>, Up: <a rel="up" accesskey="u" href="#Introduction">Introduction</a> </div> <h3 class="section">1.5 Getting help</h3> <p>A mailing list where users of Libidn may help each other exists, and you can reach it by sending e-mail to <a href="mailto:help-libidn@gnu.org">help-libidn@gnu.org</a>. Archives of the mailing list discussions, and an interface to manage subscriptions, is available through the World Wide Web at <a href="http://lists.gnu.org/mailman/listinfo/help-libidn">http://lists.gnu.org/mailman/listinfo/help-libidn</a>. <div class="node"> <p><hr> <a name="Commercial-Support"></a> Next: <a rel="next" accesskey="n" href="#Downloading-and-Installing">Downloading and Installing</a>, Previous: <a rel="previous" accesskey="p" href="#Getting-help">Getting help</a>, Up: <a rel="up" accesskey="u" href="#Introduction">Introduction</a> </div> <h3 class="section">1.6 Commercial Support</h3> <p>Commercial support is available for users of GNU Libidn. The kind of support that can be purchased may include: <ul> <li>Implement new features. Such as country code specific profiling to support a restricted subset of Unicode. <li>Port Libidn to new platforms. This could include porting Libidn to an embedded platforms that may need memory or size optimization. <li>Integrating IDN support in your existing project. <li>System design of components related to IDN. </ul> <p>If you are interested, please write to: <pre class="verbatim"> Simon Josefsson Datakonsult Hagagatan 24 113 47 Stockholm Sweden E-mail: simon@josefsson.org </pre> <p>If your company provide support related to GNU Libidn and would like to be mentioned here, contact the author (see <a href="#Bug-Reports">Bug Reports</a>). <div class="node"> <p><hr> <a name="Downloading-and-Installing"></a> Next: <a rel="next" accesskey="n" href="#Bug-Reports">Bug Reports</a>, Previous: <a rel="previous" accesskey="p" href="#Commercial-Support">Commercial Support</a>, Up: <a rel="up" accesskey="u" href="#Introduction">Introduction</a> </div> <h3 class="section">1.7 Downloading and Installing</h3> <p><a name="index-Installation-33"></a><a name="index-Download-34"></a> The package can be downloaded from several places, including: <p><a href="http://josefsson.org/libidn/releases/">http://josefsson.org/libidn/releases/</a> <p>The latest version is stored in a file, e.g., `<samp><span class="samp">gsasl-0.6.14.tar.gz</span></samp>' where the `<samp><span class="samp">0.6.14</span></samp>' value is the highest version number in the directory. <p>The package is then extracted, configured and built like many other packages that use Autoconf. For detailed information on configuring and building it, refer to the <samp><span class="file">INSTALL</span></samp> file that is part of the distribution archive. <p>Here is an example terminal session that download, configure, build and install the package. You will need a few basic tools, such as `<samp><span class="samp">sh</span></samp>', `<samp><span class="samp">make</span></samp>' and `<samp><span class="samp">cc</span></samp>'. <pre class="example"> $ wget -q http://josefsson.org/libidn/releases/libidn-0.6.14.tar.gz $ tar xfz libidn-0.6.14.tar.gz $ cd libidn-0.6.14/ $ ./configure ... $ make ... $ make install ... </pre> <p>After that Libidn should be properly installed and ready for use. <p>A few <code>configure</code> options may be relevant, summarized in the table. <dl> <dt><code>--enable-java</code><dd>Build the Java port into a *.JAR file. See <a href="#Java-API">Java API</a>, for more information. <br><dt><code>--disable-tld</code><dd>Disable the TLD module. This would typically only be useful if you are building on a memory restricted platforms. See <a href="#TLD-Functions">TLD Functions</a>, for more information. <br><dt><code>--enable-csharp[=IMPL]</code><dd>Build the C3 port into a *.DLL file. See <a href="#C_0023-API">C# API</a>, for more information. Here, <code>IMPL</code> is <code>pnet</code> or <code>mono</code>, indicating whether the PNET <samp><span class="command">cscc</span></samp> compiler or the Mono <samp><span class="command">mcs</span></samp> compiler should be used, respectively. </dl> <p>For the complete list, refer to the output from <code>configure --help</code>. <div class="node"> <p><hr> <a name="Bug-Reports"></a> Next: <a rel="next" accesskey="n" href="#Contributing">Contributing</a>, Previous: <a rel="previous" accesskey="p" href="#Downloading-and-Installing">Downloading and Installing</a>, Up: <a rel="up" accesskey="u" href="#Introduction">Introduction</a> </div> <h3 class="section">1.8 Bug Reports</h3> <p><a name="index-Reporting-Bugs-35"></a> If you think you have found a bug in Libidn, please investigate it and report it. <ul> <li>Please make sure that the bug is really in Libidn, and preferably also check that it hasn't already been fixed in the latest version. <li>You have to send us a test case that makes it possible for us to reproduce the bug. <li>You also have to explain what is wrong; if you get a crash, or if the results printed are not good and in that case, in what way. Make sure that the bug report includes all information you would need to fix this kind of bug for someone else. </ul> <p>Please make an effort to produce a self-contained report, with something definite that can be tested or debugged. Vague queries or piecemeal messages are difficult to act on and don't help the development effort. <p>If your bug report is good, we will do our best to help you to get a corrected version of the software; if the bug report is poor, we won't do anything about it (apart from asking you to send better bug reports). <p>If you think something in this manual is unclear, or downright incorrect, or if the language needs to be improved, please also send a note. <p>Send your bug report to: <div align="center">`<samp><span class="samp">bug-libidn@gnu.org</span></samp>'</div> <div class="node"> <p><hr> <a name="Contributing"></a> Previous: <a rel="previous" accesskey="p" href="#Bug-Reports">Bug Reports</a>, Up: <a rel="up" accesskey="u" href="#Introduction">Introduction</a> </div> <h3 class="section">1.9 Contributing</h3> <p><a name="index-Contributing-36"></a><a name="index-Hacking-37"></a> If you want to submit a patch for inclusion – from solve a typo you discovered, up to adding support for a new feature – you should submit it as a bug report (see <a href="#Bug-Reports">Bug Reports</a>). There are some things that you can do to increase the chances for it to be included in the official package. <p>Unless your patch is very small (say, under 10 lines) we require that you assign the copyright of your work to the Free Software Foundation. This is to protect the freedom of the project. If you have not already signed papers, we will send you the necessary information when you submit your contribution. <p>For contributions that doesn't consist of actual programming code, the only guidelines are common sense. Use it. <p>For code contributions, a number of style guides will help you: <ul> <li>Coding Style. Follow the GNU Standards document (see <a href="standards.html#Top">GNU Coding Standards</a>). <p>If you normally code using another coding standard, there is no problem, but you should use `<samp><span class="samp">indent</span></samp>' to reformat the code (see <a href="indent.html#Top">GNU Indent</a>) before submitting your work. <li>Use the unified diff format `<samp><span class="samp">diff -u</span></samp>'. <li>Return errors. No reason whatsoever should abort the execution of the library. Even memory allocation errors, e.g. when malloc return NULL, should work although result in an error code. <li>Design with thread safety in mind. Don't use global variables and the like. <li>Avoid using the C math library. It causes problems for embedded implementations, and in most situations it is very easy to avoid using it. <li>Document your functions. Use comments before each function headers, that, if properly formatted, are extracted into GTK-DOC web pages. Don't forget to update the Texinfo manual as well. <li>Supply a ChangeLog and NEWS entries, where appropriate. </ul> <!-- ********************************************************** --> <!-- ******************* Preparation ************************ --> <!-- ********************************************************** --> <div class="node"> <p><hr> <a name="Preparation"></a> Next: <a rel="next" accesskey="n" href="#Utility-Functions">Utility Functions</a>, Previous: <a rel="previous" accesskey="p" href="#Introduction">Introduction</a>, Up: <a rel="up" accesskey="u" href="#Top">Top</a> </div> <h2 class="chapter">2 Preparation</h2> <p>To use `Libidn', you have to perform some changes to your sources and the build system. The necessary changes are small and explained in the following sections. At the end of this chapter, it is described how the library is initialized, and how the requirements of the library are verified. <p>A faster way to find out how to adapt your application for use with `Libidn' may be to look at the examples at the end of this manual (see <a href="#Examples">Examples</a>). <ul class="menu"> <li><a accesskey="1" href="#Header">Header</a> <li><a accesskey="2" href="#Initialization">Initialization</a> <li><a accesskey="3" href="#Version-Check">Version Check</a> <li><a accesskey="4" href="#Building-the-source">Building the source</a> <li><a accesskey="5" href="#Autoconf-tests">Autoconf tests</a> </ul> <div class="node"> <p><hr> <a name="Header"></a> Next: <a rel="next" accesskey="n" href="#Initialization">Initialization</a>, Up: <a rel="up" accesskey="u" href="#Preparation">Preparation</a> </div> <h3 class="section">2.1 Header</h3> <p>The library contains a few independent parts, and each part export the interfaces (data types and functions) in a header file. You must include the appropriate header files in all programs using the library, either directly or through some other header file, like this: <pre class="example"> #include <stringprep.h> </pre> <p>The header files and the functions they define are categorized as follows: <dl> <dt>stringprep.h<dd> The low-level stringprep API entry point. For IDN applications, this is usually invoked via IDNA. Some applications, specifically non-IDN ones, may want to prepare strings directly though, and should include this header file. <p>The name space of the stringprep part of Libidn is <code>stringprep*</code> for function names, <code>Stringprep*</code> for data types and <code>STRINGPREP_*</code> for other symbols. In addition, <code>_stringprep*</code> is reserved for internal use and should never be used by applications. <br><dt>punycode.h<dd> The entry point to Punycode encoding and decoding functions. Normally punycode is used via the idna.h interface, but some application may want to perform raw punycode operations. <p>The name space of the punycode part of Libidn is <code>punycode_*</code> for function names, <code>Punycode*</code> for data types and <code>PUNYCODE_*</code> for other symbols. In addition, <code>_punycode*</code> is reserved for internal use and should never be used by applications. <br><dt>idna.h<dd> The entry point to the IDNA functions. This is the normal entry point for applications that need IDN functionality. <p>The name space of the IDNA part of Libidn is <code>idna_*</code> for function names, <code>Idna*</code> for data types and <code>IDNA_*</code> for other symbols. In addition, <code>_idna*</code> is reserved for internal use and should never be used by applications. <br><dt>tld.h<dd> The entry point to the TLD functions. Normal applications are not expected to need this functionality, but it is present for applications that are used by TLDs to validate customer input. <p>The name space of the TLD part of Libidn is <code>tld_*</code> for function names, <code>Tld_*</code> for data types and <code>TLD_*</code> for other symbols. In addition, <code>_tld*</code> is reserved for internal use and should never be used by applications. <br><dt>pr29.h<dd> The entry point to the PR29 functions. These functions are used to detect “problem sequences” (see <a href="#PR29-Functions">PR29 Functions</a>), mostly for use in security critical applications. <p>The name space of the PR29 part of Libidn is <code>pr29_*</code> for function names, <code>Pr29_*</code> for data types and <code>PR29_*</code> for other symbols. In addition, <code>_pr29*</code> is reserved for internal use and should never be used by applications. </dl> <div class="node"> <p><hr> <a name="Initialization"></a> Next: <a rel="next" accesskey="n" href="#Version-Check">Version Check</a>, Previous: <a rel="previous" accesskey="p" href="#Header">Header</a>, Up: <a rel="up" accesskey="u" href="#Preparation">Preparation</a> </div> <h3 class="section">2.2 Initialization</h3> <p>Libidn is stateless and does not need any initialization. <div class="node"> <p><hr> <a name="Version-Check"></a> Next: <a rel="next" accesskey="n" href="#Building-the-source">Building the source</a>, Previous: <a rel="previous" accesskey="p" href="#Initialization">Initialization</a>, Up: <a rel="up" accesskey="u" href="#Preparation">Preparation</a> </div> <h3 class="section">2.3 Version Check</h3> <p>It is often desirable to check that the version of `Libidn' used is indeed one which fits all requirements. Even with binary compatibility new features may have been introduced but due to problem with the dynamic linker an old version is actually used. So you may want to check that the version is okay right after program startup. <h4 class="subheading">stringprep_check_version</h4> <p><a name="stringprep_005fcheck_005fversion"></a> <div class="defun"> — Function: const char * <b>stringprep_check_version</b> (<var>const char * req_version</var>)<var><a name="index-stringprep_005fcheck_005fversion-38"></a></var><br> <blockquote><p><var>req_version</var>: Required version number, or NULL. <p>Check that the the version of the library is at minimum the requested one and return the version string; return NULL if the condition is not satisfied. If a NULL is passed to this function, no check is done, but the version string is simply returned. <p>See <code>STRINGPREP_VERSION</code> for a suitable <code>req_version</code> string. <p><strong>Return value:</strong> Version string of run-time library, or NULL if the run-time library does not meet the required version number. </p></blockquote></div> <p>The normal way to use the function is to put something similar to the following first in your <code>main</code>: <pre class="example"> if (!stringprep_check_version (STRINGPREP_VERSION)) { printf ("stringprep_check_version() failed:\n" "Header file incompatible with shared library.\n"); exit(1); } </pre> <div class="node"> <p><hr> <a name="Building-the-source"></a> Next: <a rel="next" accesskey="n" href="#Autoconf-tests">Autoconf tests</a>, Previous: <a rel="previous" accesskey="p" href="#Version-Check">Version Check</a>, Up: <a rel="up" accesskey="u" href="#Preparation">Preparation</a> </div> <h3 class="section">2.4 Building the source</h3> <p><a name="index-Compiling-your-application-39"></a> If you want to compile a source file including e.g. the `idna.h' header file, you must make sure that the compiler can find it in the directory hierarchy. This is accomplished by adding the path to the directory in which the header file is located to the compilers include file search path (via the <samp><span class="option">-I</span></samp> option). <p>However, the path to the include file is determined at the time the source is configured. To solve this problem, `Libidn' uses the external package <samp><span class="command">pkg-config</span></samp> that knows the path to the include file and other configuration options. The options that need to be added to the compiler invocation at compile time are output by the <samp><span class="option">--cflags</span></samp> option to <samp><span class="command">pkg-config libidn</span></samp>. The following example shows how it can be used at the command line: <pre class="example"> gcc -c foo.c `pkg-config libidn --cflags` </pre> <p>Adding the output of `<samp><span class="samp">pkg-config libidn --cflags</span></samp>' to the compilers command line will ensure that the compiler can find e.g. the idna.h header file. <p>A similar problem occurs when linking the program with the library. Again, the compiler has to find the library files. For this to work, the path to the library files has to be added to the library search path (via the <samp><span class="option">-L</span></samp> option). For this, the option <samp><span class="option">--libs</span></samp> to <samp><span class="command">pkg-config libidn</span></samp> can be used. For convenience, this option also outputs all other options that are required to link the program with the `libidn' libarary. The example shows how to link <samp><span class="file">foo.o</span></samp> with the `libidn' library to a program <samp><span class="command">foo</span></samp>. <pre class="example"> gcc -o foo foo.o `pkg-config libidn --libs` </pre> <p>Of course you can also combine both examples to a single command by specifying both options to <samp><span class="command">pkg-config</span></samp>: <pre class="example"> gcc -o foo foo.c `pkg-config libidn --cflags --libs` </pre> <div class="node"> <p><hr> <a name="Autoconf-tests"></a> Previous: <a rel="previous" accesskey="p" href="#Building-the-source">Building the source</a>, Up: <a rel="up" accesskey="u" href="#Preparation">Preparation</a> </div> <h3 class="section">2.5 Autoconf tests</h3> <p><a name="index-Autoconf-tests-40"></a><a name="index-Configure-tests-41"></a> If your project uses Autoconf (see <a href="autoconf.html#Top">GNU Autoconf</a>) to check for installed libraries, you might find the following snippet illustrative. It add a new <samp><span class="file">configure</span></samp> parameter <code>--with-libidn</code>, and check for <samp><span class="file">idna.h</span></samp> and `<samp><span class="samp">-lidn</span></samp>' (possibly below the directory specified as the optional argument to <code>--with-libidn</code>), and define the <acronym>CPP</acronym> symbol <code>LIBIDN</code> if the library is found. The default behaviour is to search for the library and enable the functionality (that is, define the symbol) when the library is found, but if you wish to make the default behaviour of your package be that Libidn is not used (even if it is installed on the system), change `<samp><span class="samp">libidn=yes</span></samp>' to `<samp><span class="samp">libidn=no</span></samp>' on the third line. <pre class="example"> AC_ARG_WITH(libidn, AC_HELP_STRING([--with-libidn=[DIR]], [Support IDN (needs GNU Libidn)]), libidn=$withval, libidn=yes) if test "$libidn" != "no"; then if test "$libidn" != "yes"; then LDFLAGS="${LDFLAGS} -L$libidn/lib" CPPFLAGS="${CPPFLAGS} -I$libidn/include" fi AC_CHECK_HEADER(idna.h, AC_CHECK_LIB(idn, stringprep_check_version, [libidn=yes LIBS="${LIBS} -lidn"], libidn=no), libidn=no) fi if test "$libidn" != "no" ; then AC_DEFINE(LIBIDN, 1, [Define to 1 if you want IDN support.]) else AC_MSG_WARN([Libidn not found]) fi AC_MSG_CHECKING([if Libidn should be used]) AC_MSG_RESULT($libidn) </pre> <p>If you require that your users have installed <code>pkg-config</code> (which I cannot recommend generally), the above can be done more easily as follows. <pre class="example"> AC_ARG_WITH(libidn, AC_HELP_STRING([--with-libidn=[DIR]], [Support IDN (needs GNU Libidn)]), libidn=$withval, libidn=yes) if test "$libidn" != "no" ; then PKG_CHECK_MODULES(LIBIDN, libidn >= 0.0.0, [libidn=yes], [libidn=no]) if test "$libidn" != "yes" ; then libidn=no AC_MSG_WARN([Libidn not found]) else libidn=yes AC_DEFINE(LIBIDN, 1, [Define to 1 if you want Libidn.]) fi fi AC_MSG_CHECKING([if Libidn should be used]) AC_MSG_RESULT($libidn) </pre> <!-- ********************************************************** --> <!-- ******************** Utility Functions ****************** --> <!-- ********************************************************** --> <div class="node"> <p><hr> <a name="Utility-Functions"></a> Next: <a rel="next" accesskey="n" href="#Stringprep-Functions">Stringprep Functions</a>, Previous: <a rel="previous" accesskey="p" href="#Preparation">Preparation</a>, Up: <a rel="up" accesskey="u" href="#Top">Top</a> </div> <h2 class="chapter">3 Utility Functions</h2> <p><a name="index-Utility-Functions-42"></a> The rest of this library makes extensive use of Unicode characters. In order to interface this library with the outside world, your application may need to make various Unicode transformations. <h3 class="section">3.1 Header file <code>stringprep.h</code></h3> <p>To use the functions explained in this chapter, you need to include the file <samp><span class="file">stringprep.h</span></samp> using: <pre class="example"> #include <stringprep.h> </pre> <h3 class="section">3.2 Unicode Encoding Transformation</h3> <h4 class="subheading">stringprep_unichar_to_utf8</h4> <p><a name="stringprep_005funichar_005fto_005futf8"></a> <div class="defun"> — Function: int <b>stringprep_unichar_to_utf8</b> (<var>uint32_t c, char * outbuf</var>)<var><a name="index-stringprep_005funichar_005fto_005futf8-43"></a></var><br> <blockquote><p><var>c</var>: a ISO10646 character code <p><var>outbuf</var>: output buffer, must have at least 6 bytes of space. If <code>NULL</code>, the length will be computed and returned and nothing will be written to <code>outbuf</code>. <p>Converts a single character to UTF-8. <p><strong>Return value:</strong> number of bytes written. </p></blockquote></div> <h4 class="subheading">stringprep_utf8_to_unichar</h4> <p><a name="stringprep_005futf8_005fto_005funichar"></a> <div class="defun"> — Function: uint32_t <b>stringprep_utf8_to_unichar</b> (<var>const char * p</var>)<var><a name="index-stringprep_005futf8_005fto_005funichar-44"></a></var><br> <blockquote><p><var>p</var>: a pointer to Unicode character encoded as UTF-8 <p>Converts a sequence of bytes encoded as UTF-8 to a Unicode character. If <code>p</code> does not point to a valid UTF-8 encoded character, results are undefined. <p><strong>Return value:</strong> the resulting character. </p></blockquote></div> <h4 class="subheading">stringprep_ucs4_to_utf8</h4> <p><a name="stringprep_005fucs4_005fto_005futf8"></a> <div class="defun"> — Function: char * <b>stringprep_ucs4_to_utf8</b> (<var>const uint32_t * str, ssize_t len, size_t * items_read, size_t * items_written</var>)<var><a name="index-stringprep_005fucs4_005fto_005futf8-45"></a></var><br> <blockquote><p><var>str</var>: a UCS-4 encoded string <p><var>len</var>: the maximum length of <code>str</code> to use. If <code>len</code> < 0, then the string is terminated with a 0 character. <p><var>items_read</var>: location to store number of characters read read, or <code>NULL</code>. <p><var>items_written</var>: location to store number of bytes written or <code>NULL</code>. The value here stored does not include the trailing 0 byte. <p>Convert a string from a 32-bit fixed width representation as UCS-4. to UTF-8. The result will be terminated with a 0 byte. <p><strong>Return value:</strong> a pointer to a newly allocated UTF-8 string. This value must be freed with <code>free()</code>. If an error occurs, <code>NULL</code> will be returned and <code>error</code> set. </p></blockquote></div> <h4 class="subheading">stringprep_utf8_to_ucs4</h4> <p><a name="stringprep_005futf8_005fto_005fucs4"></a> <div class="defun"> — Function: uint32_t * <b>stringprep_utf8_to_ucs4</b> (<var>const char * str, ssize_t len, size_t * items_written</var>)<var><a name="index-stringprep_005futf8_005fto_005fucs4-46"></a></var><br> <blockquote><p><var>str</var>: a UTF-8 encoded string <p><var>len</var>: the maximum length of <code>str</code> to use. If <code>len</code> < 0, then the string is nul-terminated. <p><var>items_written</var>: location to store the number of characters in the result, or <code>NULL</code>. <p>Convert a string from UTF-8 to a 32-bit fixed width representation as UCS-4, assuming valid UTF-8 input. This function does no error checking on the input. <p><strong>Return value:</strong> a pointer to a newly allocated UCS-4 string. This value must be freed with <code>free()</code>. </p></blockquote></div> <h3 class="section">3.3 Unicode Normalization</h3> <h4 class="subheading">stringprep_ucs4_nfkc_normalize</h4> <p><a name="stringprep_005fucs4_005fnfkc_005fnormalize"></a> <div class="defun"> — Function: uint32_t * <b>stringprep_ucs4_nfkc_normalize</b> (<var>uint32_t * str, ssize_t len</var>)<var><a name="index-stringprep_005fucs4_005fnfkc_005fnormalize-47"></a></var><br> <blockquote><p><var>str</var>: a Unicode string. <p><var>len</var>: length of <code>str</code> array, or -1 if <code>str</code> is nul-terminated. <p>Converts UCS4 string into UTF-8 and runs <code>stringprep_utf8_nfkc_normalize()</code>. <p><strong>Return value:</strong> a newly allocated Unicode string, that is the NFKC normalized form of <code>str</code>. </p></blockquote></div> <h4 class="subheading">stringprep_utf8_nfkc_normalize</h4> <p><a name="stringprep_005futf8_005fnfkc_005fnormalize"></a> <div class="defun"> — Function: char * <b>stringprep_utf8_nfkc_normalize</b> (<var>const char * str, ssize_t len</var>)<var><a name="index-stringprep_005futf8_005fnfkc_005fnormalize-48"></a></var><br> <blockquote><p><var>str</var>: a UTF-8 encoded string. <p><var>len</var>: length of <code>str</code>, in bytes, or -1 if <code>str</code> is nul-terminated. <p>Converts a string into canonical form, standardizing such issues as whether a character with an accent is represented as a base character and combining accent or as a single precomposed character. <p>The normalization mode is NFKC (ALL COMPOSE). It standardizes differences that do not affect the text content, such as the above-mentioned accent representation. It standardizes the "compatibility" characters in Unicode, such as SUPERSCRIPT THREE to the standard forms (in this case DIGIT THREE). Formatting information may be lost but for most text operations such characters should be considered the same. It returns a result with composed forms rather than a maximally decomposed form. <p><strong>Return value:</strong> a newly allocated string, that is the NFKC normalized form of <code>str</code>. </p></blockquote></div> <h3 class="section">3.4 Character Set Conversion</h3> <h4 class="subheading">stringprep_locale_charset</h4> <p><a name="stringprep_005flocale_005fcharset"></a> <div class="defun"> — Function: const char * <b>stringprep_locale_charset</b> (<var> void</var>)<var><a name="index-stringprep_005flocale_005fcharset-49"></a></var><br> <blockquote> <p>Find out current locale charset. The function respect the CHARSET environment variable, but typically uses nl_langinfo(CODESET) when it is supported. It fall back on "ASCII" if CHARSET isn't set and nl_langinfo isn't supported or return anything. <p>Note that this function return the application's locale's preferred charset (or thread's locale's preffered charset, if your system support thread-specific locales). It does not return what the system may be using. Thus, if you receive data from external sources you cannot in general use this function to guess what charset it is encoded in. Use stringprep_convert from the external representation into the charset returned by this function, to have data in the locale encoding. <p><strong>Return value:</strong> Return the character set used by the current locale. It will never return NULL, but use "ASCII" as a fallback. </p></blockquote></div> <h4 class="subheading">stringprep_convert</h4> <p><a name="stringprep_005fconvert"></a> <div class="defun"> — Function: char * <b>stringprep_convert</b> (<var>const char * str, const char * to_codeset, const char * from_codeset</var>)<var><a name="index-stringprep_005fconvert-50"></a></var><br> <blockquote><p><var>str</var>: input zero-terminated string. <p><var>to_codeset</var>: name of destination character set. <p><var>from_codeset</var>: name of origin character set, as used by <code>str</code>. <p>Convert the string from one character set to another using the system's <code>iconv()</code> function. <p><strong>Return value:</strong> Returns newly allocated zero-terminated string which is <code>str</code> transcoded into to_codeset. </p></blockquote></div> <h4 class="subheading">stringprep_locale_to_utf8</h4> <p><a name="stringprep_005flocale_005fto_005futf8"></a> <div class="defun"> — Function: char * <b>stringprep_locale_to_utf8</b> (<var>const char * str</var>)<var><a name="index-stringprep_005flocale_005fto_005futf8-51"></a></var><br> <blockquote><p><var>str</var>: input zero terminated string. <p>Convert string encoded in the locale's character set into UTF-8 by using <code>stringprep_convert()</code>. <p><strong>Return value:</strong> Returns newly allocated zero-terminated string which is <code>str</code> transcoded into UTF-8. </p></blockquote></div> <h4 class="subheading">stringprep_utf8_to_locale</h4> <p><a name="stringprep_005futf8_005fto_005flocale"></a> <div class="defun"> — Function: char * <b>stringprep_utf8_to_locale</b> (<var>const char * str</var>)<var><a name="index-stringprep_005futf8_005fto_005flocale-52"></a></var><br> <blockquote><p><var>str</var>: input zero terminated string. <p>Convert string encoded in UTF-8 into the locale's character set by using <code>stringprep_convert()</code>. <p><strong>Return value:</strong> Returns newly allocated zero-terminated string which is <code>str</code> transcoded into the locale's character set. </p></blockquote></div> <!-- ********************************************************** --> <!-- ****************** Stringprep Functions ***************** --> <!-- ********************************************************** --> <div class="node"> <p><hr> <a name="Stringprep-Functions"></a> Next: <a rel="next" accesskey="n" href="#Punycode-Functions">Punycode Functions</a>, Previous: <a rel="previous" accesskey="p" href="#Utility-Functions">Utility Functions</a>, Up: <a rel="up" accesskey="u" href="#Top">Top</a> </div> <h2 class="chapter">4 Stringprep Functions</h2> <p><a name="index-Stringprep-Functions-53"></a> Stringprep describes a framework for preparing Unicode text strings in order to increase the likelihood that string input and string comparison work in ways that make sense for typical users throughout the world. The stringprep protocol is useful for protocol identifier values, company and personal names, internationalized domain names, and other text strings. <h3 class="section">4.1 Header file <code>stringprep.h</code></h3> <p>To use the functions explained in this chapter, you need to include the file <samp><span class="file">stringprep.h</span></samp> using: <pre class="example"> #include <stringprep.h> </pre> <h3 class="section">4.2 Defining A Stringprep Profile</h3> <p>Further types and structures are defined for applications that want to specify their own stringprep profile. As these are fairly obscure, and by necessity tied to the implementation, we do not document them here. Look into the <samp><span class="file">stringprep.h</span></samp> header file, and the <samp><span class="file">profiles.c</span></samp> source code for the details. <h3 class="section">4.3 Control Flags</h3> <div class="defun"> — Stringprep flags: Stringprep_profile_flags <b>STRINGPREP_NO_NFKC</b><var><a name="index-STRINGPREP_005fNO_005fNFKC-54"></a></var><br> <blockquote><p>Disable the NFKC normalization, as well as selecting the non-NFKC case folding tables. Usually the profile specifies BIDI and NFKC settings, and applications should not override it unless in special situations. </p></blockquote></div> <div class="defun"> — Stringprep flags: Stringprep_profile_flags <b>STRINGPREP_NO_BIDI</b><var><a name="index-STRINGPREP_005fNO_005fBIDI-55"></a></var><br> <blockquote><p>Disable the BIDI step. Usually the profile specifies BIDI and NFKC settings, and applications should not override it unless in special situations. </p></blockquote></div> <div class="defun"> — Stringprep flags: Stringprep_profile_flags <b>STRINGPREP_NO_UNASSIGNED</b><var><a name="index-STRINGPREP_005fNO_005fUNASSIGNED-56"></a></var><br> <blockquote><p>Make the library return with an error if string contains unassigned characters according to profile. </p></blockquote></div> <h3 class="section">4.4 Core Functions</h3> <h4 class="subheading">stringprep_4i</h4> <p><a name="stringprep_005f4i"></a> <div class="defun"> — Function: int <b>stringprep_4i</b> (<var>uint32_t * ucs4, size_t * len, size_t maxucs4len, Stringprep_profile_flags flags, const Stringprep_profile * profile</var>)<var><a name="index-stringprep_005f4i-57"></a></var><br> <blockquote><p><var>ucs4</var>: input/output array with string to prepare. <p><var>len</var>: on input, length of input array with Unicode code points, on exit, length of output array with Unicode code points. <p><var>maxucs4len</var>: maximum length of input/output array. <p><var>flags</var>: a <code>Stringprep_profile_flags</code> value, or 0. <p><var>profile</var>: pointer to <code>Stringprep_profile</code> to use. <p>Prepare the input UCS-4 string according to the stringprep profile, and write back the result to the input string. <p>The input is not required to be zero terminated (<code>ucs4</code>[<code>len</code>] = 0). The output will not be zero terminated unless <code>ucs4</code>[<code>len</code>] = 0. Instead, see <code>stringprep_4zi()</code> if your input is zero terminated or if you want the output to be. <p>Since the stringprep operation can expand the string, <code>maxucs4len</code> indicate how large the buffer holding the string is. This function will not read or write to code points outside that size. <p>The <code>flags</code> are one of <code>Stringprep_profile_flags</code> values, or 0. <p>The <code>profile</code> contain the <code>Stringprep_profile</code> instructions to perform. Your application can define new profiles, possibly re-using the generic stringprep tables that always will be part of the library, or use one of the currently supported profiles. <p><strong>Return value:</strong> Returns <code>STRINGPREP_OK</code> iff successful, or an <code>Stringprep_rc</code> error code. </p></blockquote></div> <h4 class="subheading">stringprep_4zi</h4> <p><a name="stringprep_005f4zi"></a> <div class="defun"> — Function: int <b>stringprep_4zi</b> (<var>uint32_t * ucs4, size_t maxucs4len, Stringprep_profile_flags flags, const Stringprep_profile * profile</var>)<var><a name="index-stringprep_005f4zi-58"></a></var><br> <blockquote><p><var>ucs4</var>: input/output array with zero terminated string to prepare. <p><var>maxucs4len</var>: maximum length of input/output array. <p><var>flags</var>: a <code>Stringprep_profile_flags</code> value, or 0. <p><var>profile</var>: pointer to <code>Stringprep_profile</code> to use. <p>Prepare the input zero terminated UCS-4 string according to the stringprep profile, and write back the result to the input string. <p>Since the stringprep operation can expand the string, <code>maxucs4len</code> indicate how large the buffer holding the string is. This function will not read or write to code points outside that size. <p>The <code>flags</code> are one of <code>Stringprep_profile_flags</code> values, or 0. <p>The <code>profile</code> contain the <code>Stringprep_profile</code> instructions to perform. Your application can define new profiles, possibly re-using the generic stringprep tables that always will be part of the library, or use one of the currently supported profiles. <p><strong>Return value:</strong> Returns <code>STRINGPREP_OK</code> iff successful, or an <code>Stringprep_rc</code> error code. </p></blockquote></div> <h4 class="subheading">stringprep</h4> <p><a name="stringprep"></a> <div class="defun"> — Function: int <b>stringprep</b> (<var>char * in, size_t maxlen, Stringprep_profile_flags flags, const Stringprep_profile * profile</var>)<var><a name="index-stringprep-59"></a></var><br> <blockquote><p><var>in</var>: input/ouput array with string to prepare. <p><var>maxlen</var>: maximum length of input/output array. <p><var>flags</var>: a <code>Stringprep_profile_flags</code> value, or 0. <p><var>profile</var>: pointer to <code>Stringprep_profile</code> to use. <p>Prepare the input zero terminated UTF-8 string according to the stringprep profile, and write back the result to the input string. <p>Note that you must convert strings entered in the systems locale into UTF-8 before using this function, see <code>stringprep_locale_to_utf8()</code>. <p>Since the stringprep operation can expand the string, <code>maxlen</code> indicate how large the buffer holding the string is. This function will not read or write to characters outside that size. <p>The <code>flags</code> are one of <code>Stringprep_profile_flags</code> values, or 0. <p>The <code>profile</code> contain the <code>Stringprep_profile</code> instructions to perform. Your application can define new profiles, possibly re-using the generic stringprep tables that always will be part of the library, or use one of the currently supported profiles. <p><strong>Return value:</strong> Returns <code>STRINGPREP_OK</code> iff successful, or an error code. </p></blockquote></div> <h4 class="subheading">stringprep_profile</h4> <p><a name="stringprep_005fprofile"></a> <div class="defun"> — Function: int <b>stringprep_profile</b> (<var>const char * in, char ** out, const char * profile, Stringprep_profile_flags flags</var>)<var><a name="index-stringprep_005fprofile-60"></a></var><br> <blockquote><p><var>in</var>: input array with UTF-8 string to prepare. <p><var>out</var>: output variable with pointer to newly allocate string. <p><var>profile</var>: name of stringprep profile to use. <p><var>flags</var>: a <code>Stringprep_profile_flags</code> value, or 0. <p>Prepare the input zero terminated UTF-8 string according to the stringprep profile, and return the result in a newly allocated variable. <p>Note that you must convert strings entered in the systems locale into UTF-8 before using this function, see <code>stringprep_locale_to_utf8()</code>. <p>The output <code>out</code> variable must be deallocated by the caller. <p>The <code>flags</code> are one of <code>Stringprep_profile_flags</code> values, or 0. <p>The <code>profile</code> specifies the name of the stringprep profile to use. It must be one of the internally supported stringprep profiles. <p><strong>Return value:</strong> Returns <code>STRINGPREP_OK</code> iff successful, or an error code. </p></blockquote></div> <h3 class="section">4.5 Error Handling</h3> <h4 class="subheading">stringprep_strerror</h4> <p><a name="stringprep_005fstrerror"></a> <div class="defun"> — Function: const char * <b>stringprep_strerror</b> (<var>Stringprep_rc rc</var>)<var><a name="index-stringprep_005fstrerror-61"></a></var><br> <blockquote><p><var>rc</var>: a <code>Stringprep_rc</code> return code. <p>Convert a return code integer to a text string. This string can be used to output a diagnostic message to the user. <p><strong>STRINGPREP_OK:</strong> Successful operation. This value is guaranteed to always be zero, the remaining ones are only guaranteed to hold non-zero values, for logical comparison purposes. <p><strong>STRINGPREP_CONTAINS_UNASSIGNED:</strong> String contain unassigned Unicode code points, which is forbidden by the profile. <p><strong>STRINGPREP_CONTAINS_PROHIBITED:</strong> String contain code points prohibited by the profile. <p><strong>STRINGPREP_BIDI_BOTH_L_AND_RAL:</strong> String contain code points with conflicting bidirection category. <p><strong>STRINGPREP_BIDI_LEADTRAIL_NOT_RAL:</strong> Leading and trailing character in string not of proper bidirectional category. <p><strong>STRINGPREP_BIDI_CONTAINS_PROHIBITED:</strong> Contains prohibited code points detected by bidirectional code. <p><strong>STRINGPREP_TOO_SMALL_BUFFER:</strong> Buffer handed to function was too small. This usually indicate a problem in the calling application. <p><strong>STRINGPREP_PROFILE_ERROR:</strong> The stringprep profile was inconsistent. This usually indicate an internal error in the library. <p><strong>STRINGPREP_FLAG_ERROR:</strong> The supplied flag conflicted with profile. This usually indicate a problem in the calling application. <p><strong>STRINGPREP_UNKNOWN_PROFILE:</strong> The supplied profile name was not known to the library. <p><strong>STRINGPREP_NFKC_FAILED:</strong> The Unicode NFKC operation failed. This usually indicate an internal error in the library. <p><strong>STRINGPREP_MALLOC_ERROR:</strong> The <code>malloc()</code> was out of memory. This is usually a fatal error. <p><strong>Return value:</strong> Returns a pointer to a statically allocated string containing a description of the error with the return code <code>rc</code>. </p></blockquote></div> <h3 class="section">4.6 Stringprep Profile Macros</h3> <div class="defun"> — Function: int <b>stringprep_nameprep_no_unassigned</b> (<var>char * in, int maxlen</var>)<var><a name="index-stringprep_005fnameprep_005fno_005funassigned-62"></a></var><br> <blockquote> <p><var>in</var>: input/ouput array with string to prepare. <p><var>maxlen</var>: maximum length of input/output array. <p>Prepare the input UTF-8 string according to the nameprep profile. The AllowUnassigned flag is false, use <code>stringprep_nameprep</code> for true AllowUnassigned. Returns 0 iff successful, or an error code. </p></blockquote></div> <div class="defun"> — Function: int <b>stringprep_iscsi</b> (<var>char * in, int maxlen</var>)<var><a name="index-stringprep_005fiscsi-63"></a></var><br> <blockquote> <p><var>in</var>: input/ouput array with string to prepare. <p><var>maxlen</var>: maximum length of input/output array. <p>Prepare the input UTF-8 string according to the draft iSCSI stringprep profile. Returns 0 iff successful, or an error code. </p></blockquote></div> <div class="defun"> — Function: int <b>stringprep_plain</b> (<var>char * in, int maxlen</var>)<var><a name="index-stringprep_005fplain-64"></a></var><br> <blockquote> <p><var>in</var>: input/ouput array with string to prepare. <p><var>maxlen</var>: maximum length of input/output array. <p>Prepare the input UTF-8 string according to the draft SASL ANONYMOUS profile. Returns 0 iff successful, or an error code. </p></blockquote></div> <div class="defun"> — Function: int <b>stringprep_xmpp_nodeprep</b> (<var>char * in, int maxlen</var>)<var><a name="index-stringprep_005fxmpp_005fnodeprep-65"></a></var><br> <blockquote> <p><var>in</var>: input/ouput array with string to prepare. <p><var>maxlen</var>: maximum length of input/output array. <p>Prepare the input UTF-8 string according to the draft XMPP node identifier profile. Returns 0 iff successful, or an error code. </p></blockquote></div> <div class="defun"> — Function: int <b>stringprep_xmpp_resourceprep</b> (<var>char * in, int maxlen</var>)<var><a name="index-stringprep_005fxmpp_005fresourceprep-66"></a></var><br> <blockquote> <p><var>in</var>: input/ouput array with string to prepare. <p><var>maxlen</var>: maximum length of input/output array. <p>Prepare the input UTF-8 string according to the draft XMPP resource identifier profile. Returns 0 iff successful, or an error code. </p></blockquote></div> <!-- ********************************************************** --> <!-- ******************* Punycode Functions ****************** --> <!-- ********************************************************** --> <div class="node"> <p><hr> <a name="Punycode-Functions"></a> Next: <a rel="next" accesskey="n" href="#IDNA-Functions">IDNA Functions</a>, Previous: <a rel="previous" accesskey="p" href="#Stringprep-Functions">Stringprep Functions</a>, Up: <a rel="up" accesskey="u" href="#Top">Top</a> </div> <h2 class="chapter">5 Punycode Functions</h2> <p><a name="index-Punycode-Functions-67"></a> Punycode is a simple and efficient transfer encoding syntax designed for use with Internationalized Domain Names in Applications. It uniquely and reversibly transforms a Unicode string into an ASCII string. ASCII characters in the Unicode string are represented literally, and non-ASCII characters are represented by ASCII characters that are allowed in host name labels (letters, digits, and hyphens). A general algorithm called Bootstring allows a string of basic code points to uniquely represent any string of code points drawn from a larger set. Punycode is an instance of Bootstring that uses particular parameter values, appropriate for IDNA. <h3 class="section">5.1 Header file <code>punycode.h</code></h3> <p>To use the functions explained in this chapter, you need to include the file <samp><span class="file">punycode.h</span></samp> using: <pre class="example"> #include <punycode.h> </pre> <h3 class="section">5.2 Unicode Code Point Data Type</h3> <p>The punycode function uses a special type to denote Unicode code points. It is guaranteed to always be a 32 bit unsigned integer. <div class="defun"> — Punycode Unicode code point: uint32_t <b>punycode_uint</b><var><a name="index-punycode_005fuint-68"></a></var><br> <blockquote><p>A unsigned integer that hold Unicode code points. </p></blockquote></div> <h3 class="section">5.3 Core Functions</h3> <p>Note that the current implementation will fail if the <code>input_length</code> exceed 4294967295 (the size of <code>punycode_uint</code>). This restriction may be removed in the future. Meanwhile applications are encouraged to not depend on this problem, and use <code>sizeof</code> to initialize <code>input_length</code> and <code>output_length</code>. <p>The functions provided are the following two entry points: <h4 class="subheading">punycode_encode</h4> <p><a name="punycode_005fencode"></a> <div class="defun"> — Function: int <b>punycode_encode</b> (<var>size_t input_length, const punycode_uint </var>[]<var> input, const unsigned char </var>[]<var> case_flags, size_t * output_length, char </var>[]<var> output</var>)<var><a name="index-punycode_005fencode-69"></a></var><br> <blockquote><p><var>input_length</var>: The number of code points in the <code>input</code> array and the number of flags in the <code>case_flags</code> array. <p><var>input</var>: An array of code points. They are presumed to be Unicode code points, but that is not strictly REQUIRED. The array contains code points, not code units. UTF-16 uses code units D800 through DFFF to refer to code points 10000..10FFFF. The code points D800..DFFF do not occur in any valid Unicode string. The code points that can occur in Unicode strings (0..D7FF and E000..10FFFF) are also called Unicode scalar values. <p><var>case_flags</var>: A <code>NULL</code> pointer or an array of boolean values parallel to the <code>input</code> array. Nonzero (true, flagged) suggests that the corresponding Unicode character be forced to uppercase after being decoded (if possible), and zero (false, unflagged) suggests that it be forced to lowercase (if possible). ASCII code points (0..7F) are encoded literally, except that ASCII letters are forced to uppercase or lowercase according to the corresponding case flags. If <code>case_flags</code> is a <code>NULL</code> pointer then ASCII letters are left as they are, and other code points are treated as unflagged. <p><var>output_length</var>: The caller passes in the maximum number of ASCII code points that it can receive. On successful return it will contain the number of ASCII code points actually output. <p><var>output</var>: An array of ASCII code points. It is *not* null-terminated; it will contain zeros if and only if the <code>input</code> contains zeros. (Of course the caller can leave room for a terminator and add one if needed.) <p>Converts a sequence of code points (presumed to be Unicode code points) to Punycode. <p><strong>Return value:</strong> The return value can be any of the <code>Punycode_status</code> values defined above except <code>PUNYCODE_BAD_INPUT</code>. If not <code>PUNYCODE_SUCCESS</code>, then <code>output_size</code> and <code>output</code> might contain garbage. </p></blockquote></div> <h4 class="subheading">punycode_decode</h4> <p><a name="punycode_005fdecode"></a> <div class="defun"> — Function: int <b>punycode_decode</b> (<var>size_t input_length, const char </var>[]<var> input, size_t * output_length, punycode_uint </var>[]<var> output, unsigned char </var>[]<var> case_flags</var>)<var><a name="index-punycode_005fdecode-70"></a></var><br> <blockquote><p><var>input_length</var>: The number of ASCII code points in the <code>input</code> array. <p><var>input</var>: An array of ASCII code points (0..7F). <p><var>output_length</var>: The caller passes in the maximum number of code points that it can receive into the <code>output</code> array (which is also the maximum number of flags that it can receive into the <code>case_flags</code> array, if <code>case_flags</code> is not a <code>NULL</code> pointer). On successful return it will contain the number of code points actually output (which is also the number of flags actually output, if case_flags is not a null pointer). The decoder will never need to output more code points than the number of ASCII code points in the input, because of the way the encoding is defined. The number of code points output cannot exceed the maximum possible value of a punycode_uint, even if the supplied <code>output_length</code> is greater than that. <p><var>output</var>: An array of code points like the input argument of <code>punycode_encode()</code> (see above). <p><var>case_flags</var>: A <code>NULL</code> pointer (if the flags are not needed by the caller) or an array of boolean values parallel to the <code>output</code> array. Nonzero (true, flagged) suggests that the corresponding Unicode character be forced to uppercase by the caller (if possible), and zero (false, unflagged) suggests that it be forced to lowercase (if possible). ASCII code points (0..7F) are output already in the proper case, but their flags will be set appropriately so that applying the flags would be harmless. <p>Converts Punycode to a sequence of code points (presumed to be Unicode code points). <p><strong>Return value:</strong> The return value can be any of the <code>Punycode_status</code> values defined above. If not <code>PUNYCODE_SUCCESS</code>, then <code>output_length</code>, <code>output</code>, and <code>case_flags</code> might contain garbage. </p></blockquote></div> <h3 class="section">5.4 Error Handling</h3> <h4 class="subheading">punycode_strerror</h4> <p><a name="punycode_005fstrerror"></a> <div class="defun"> — Function: const char * <b>punycode_strerror</b> (<var>Punycode_status rc</var>)<var><a name="index-punycode_005fstrerror-71"></a></var><br> <blockquote><p><var>rc</var>: an <code>Punycode_status</code> return code. <p>Convert a return code integer to a text string. This string can be used to output a diagnostic message to the user. <p><strong>PUNYCODE_SUCCESS:</strong> Successful operation. This value is guaranteed to always be zero, the remaining ones are only guaranteed to hold non-zero values, for logical comparison purposes. <p><strong>PUNYCODE_BAD_INPUT:</strong> Input is invalid. <p><strong>PUNYCODE_BIG_OUTPUT:</strong> Output would exceed the space provided. <p><strong>PUNYCODE_OVERFLOW:</strong> Input needs wider integers to process. <p><strong>Return value:</strong> Returns a pointer to a statically allocated string containing a description of the error with the return code <code>rc</code>. </p></blockquote></div> <!-- ********************************************************** --> <!-- ********************* IDNA Functions ********************* --> <!-- ********************************************************** --> <div class="node"> <p><hr> <a name="IDNA-Functions"></a> Next: <a rel="next" accesskey="n" href="#TLD-Functions">TLD Functions</a>, Previous: <a rel="previous" accesskey="p" href="#Punycode-Functions">Punycode Functions</a>, Up: <a rel="up" accesskey="u" href="#Top">Top</a> </div> <h2 class="chapter">6 IDNA Functions</h2> <p><a name="index-IDNA-Functions-72"></a> Until now, there has been no standard method for domain names to use characters outside the ASCII repertoire. The IDNA document defines internationalized domain names (IDNs) and a mechanism called IDNA for handling them in a standard fashion. IDNs use characters drawn from a large repertoire (Unicode), but IDNA allows the non-ASCII characters to be represented using only the ASCII characters already allowed in so-called host names today. This backward-compatible representation is required in existing protocols like DNS, so that IDNs can be introduced with no changes to the existing infrastructure. IDNA is only meant for processing domain names, not free text. <h3 class="section">6.1 Header file <code>idna.h</code></h3> <p>To use the functions explained in this chapter, you need to include the file <samp><span class="file">idna.h</span></samp> using: <pre class="example"> #include <idna.h> </pre> <h3 class="section">6.2 Control Flags</h3> <p>The IDNA <code>flags</code> parameter can take on the following values, or a bit-wise inclusive or of any subset of the parameters: <div class="defun"> — Return code: Idna_flags <b>IDNA_ALLOW_UNASSIGNED</b><var><a name="index-IDNA_005fALLOW_005fUNASSIGNED-73"></a></var><br> <blockquote><p>Allow unassigned Unicode code points. </p></blockquote></div> <div class="defun"> — Return code: Idna_flags <b>IDNA_USE_STD3_ASCII_RULES</b><var><a name="index-IDNA_005fUSE_005fSTD3_005fASCII_005fRULES-74"></a></var><br> <blockquote><p>Check output to make sure it is a STD3 conforming host name. </p></blockquote></div> <h3 class="section">6.3 Prefix String</h3> <div class="defun"> — Macro: #define <b>IDNA_ACE_PREFIX</b><var><a name="index-IDNA_005fACE_005fPREFIX-75"></a></var><br> <blockquote><p>String with the official IDNA prefix, <code>xn--</code>. </p></blockquote></div> <h3 class="section">6.4 Core Functions</h3> <p>The idea behind the IDNA function names are as follows: the <code>idna_to_ascii_4i</code> and <code>idna_to_unicode_44i</code> functions are the core IDNA primitives. The <code>4</code> indicate that the function takes UCS-4 strings (i.e., Unicode code points encoded in a 32-bit unsigned integer type) of the specified length. The <code>i</code> indicate that the data is written “inline” into the buffer. This means the caller is responsible for allocating (and deallocating) the string, and providing the library with the allocated length of the string. The output length is written in the output length variable. The remaining functions all contain the <code>z</code> indicator, which means the strings are zero terminated. All output strings are allocated by the library, and must be deallocated by the caller. The <code>4</code> indicator again means that the string is UCS-4, the <code>8</code> means the strings are UTF-8 and the <code>l</code> indicator means the strings are encoded in the encoding used by the current locale. <p>The functions provided are the following entry points: <h4 class="subheading">idna_to_ascii_4i</h4> <p><a name="idna_005fto_005fascii_005f4i"></a> <div class="defun"> — Function: int <b>idna_to_ascii_4i</b> (<var>const uint32_t * in, size_t inlen, char * out, int flags</var>)<var><a name="index-idna_005fto_005fascii_005f4i-76"></a></var><br> <blockquote><p><var>in</var>: input array with unicode code points. <p><var>inlen</var>: length of input array with unicode code points. <p><var>out</var>: output zero terminated string that must have room for at least 63 characters plus the terminating zero. <p><var>flags</var>: an <code>Idna_flags</code> value, e.g., <code>IDNA_ALLOW_UNASSIGNED</code> or <code>IDNA_USE_STD3_ASCII_RULES</code>. <p>The ToASCII operation takes a sequence of Unicode code points that make up one label and transforms it into a sequence of code points in the ASCII range (0..7F). If ToASCII succeeds, the original sequence and the resulting sequence are equivalent labels. <p>It is important to note that the ToASCII operation can fail. ToASCII fails if any step of it fails. If any step of the ToASCII operation fails on any label in a domain name, that domain name MUST NOT be used as an internationalized domain name. The method for deadling with this failure is application-specific. <p>The inputs to ToASCII are a sequence of code points, the AllowUnassigned flag, and the UseSTD3ASCIIRules flag. The output of ToASCII is either a sequence of ASCII code points or a failure condition. <p>ToASCII never alters a sequence of code points that are all in the ASCII range to begin with (although it could fail). Applying the ToASCII operation multiple times has exactly the same effect as applying it just once. <p><strong>Return value:</strong> Returns 0 on success, or an <code>Idna_rc</code> error code. </p></blockquote></div> <h4 class="subheading">idna_to_unicode_44i</h4> <p><a name="idna_005fto_005funicode_005f44i"></a> <div class="defun"> — Function: int <b>idna_to_unicode_44i</b> (<var>const uint32_t * in, size_t inlen, uint32_t * out, size_t * outlen, int flags</var>)<var><a name="index-idna_005fto_005funicode_005f44i-77"></a></var><br> <blockquote><p><var>in</var>: input array with unicode code points. <p><var>inlen</var>: length of input array with unicode code points. <p><var>out</var>: output array with unicode code points. <p><var>outlen</var>: on input, maximum size of output array with unicode code points, on exit, actual size of output array with unicode code points. <p><var>flags</var>: an <code>Idna_flags</code> value, e.g., <code>IDNA_ALLOW_UNASSIGNED</code> or <code>IDNA_USE_STD3_ASCII_RULES</code>. <p>The ToUnicode operation takes a sequence of Unicode code points that make up one label and returns a sequence of Unicode code points. If the input sequence is a label in ACE form, then the result is an equivalent internationalized label that is not in ACE form, otherwise the original sequence is returned unaltered. <p>ToUnicode never fails. If any step fails, then the original input sequence is returned immediately in that step. <p>The Punycode decoder can never output more code points than it inputs, but Nameprep can, and therefore ToUnicode can. Note that the number of octets needed to represent a sequence of code points depends on the particular character encoding used. <p>The inputs to ToUnicode are a sequence of code points, the AllowUnassigned flag, and the UseSTD3ASCIIRules flag. The output of ToUnicode is always a sequence of Unicode code points. <p><strong>Return value:</strong> Returns <code>Idna_rc</code> error condition, but it must only be used for debugging purposes. The output buffer is always guaranteed to contain the correct data according to the specification (sans malloc induced errors). NB! This means that you normally ignore the return code from this function, as checking it means breaking the standard. </p></blockquote></div> <h3 class="section">6.5 Simplified ToASCII Interface</h3> <h4 class="subheading">idna_to_ascii_4z</h4> <p><a name="idna_005fto_005fascii_005f4z"></a> <div class="defun"> — Function: int <b>idna_to_ascii_4z</b> (<var>const uint32_t * input, char ** output, int flags</var>)<var><a name="index-idna_005fto_005fascii_005f4z-78"></a></var><br> <blockquote><p><var>input</var>: zero terminated input Unicode string. <p><var>output</var>: pointer to newly allocated output string. <p><var>flags</var>: an <code>Idna_flags</code> value, e.g., <code>IDNA_ALLOW_UNASSIGNED</code> or <code>IDNA_USE_STD3_ASCII_RULES</code>. <p>Convert UCS-4 domain name to ASCII string. The domain name may contain several labels, separated by dots. The output buffer must be deallocated by the caller. <p><strong>Return value:</strong> Returns <code>IDNA_SUCCESS</code> on success, or error code. </p></blockquote></div> <h4 class="subheading">idna_to_ascii_8z</h4> <p><a name="idna_005fto_005fascii_005f8z"></a> <div class="defun"> — Function: int <b>idna_to_ascii_8z</b> (<var>const char * input, char ** output, int flags</var>)<var><a name="index-idna_005fto_005fascii_005f8z-79"></a></var><br> <blockquote><p><var>input</var>: zero terminated input UTF-8 string. <p><var>output</var>: pointer to newly allocated output string. <p><var>flags</var>: an <code>Idna_flags</code> value, e.g., <code>IDNA_ALLOW_UNASSIGNED</code> or <code>IDNA_USE_STD3_ASCII_RULES</code>. <p>Convert UTF-8 domain name to ASCII string. The domain name may contain several labels, separated by dots. The output buffer must be deallocated by the caller. <p><strong>Return value:</strong> Returns <code>IDNA_SUCCESS</code> on success, or error code. </p></blockquote></div> <h4 class="subheading">idna_to_ascii_lz</h4> <p><a name="idna_005fto_005fascii_005flz"></a> <div class="defun"> — Function: int <b>idna_to_ascii_lz</b> (<var>const char * input, char ** output, int flags</var>)<var><a name="index-idna_005fto_005fascii_005flz-80"></a></var><br> <blockquote><p><var>input</var>: zero terminated input string encoded in the current locale's character set. <p><var>output</var>: pointer to newly allocated output string. <p><var>flags</var>: an <code>Idna_flags</code> value, e.g., <code>IDNA_ALLOW_UNASSIGNED</code> or <code>IDNA_USE_STD3_ASCII_RULES</code>. <p>Convert domain name in the locale's encoding to ASCII string. The domain name may contain several labels, separated by dots. The output buffer must be deallocated by the caller. <p><strong>Return value:</strong> Returns <code>IDNA_SUCCESS</code> on success, or error code. </p></blockquote></div> <h3 class="section">6.6 Simplified ToUnicode Interface</h3> <h4 class="subheading">idna_to_unicode_4z4z</h4> <p><a name="idna_005fto_005funicode_005f4z4z"></a> <div class="defun"> — Function: int <b>idna_to_unicode_4z4z</b> (<var>const uint32_t * input, uint32_t ** output, int flags</var>)<var><a name="index-idna_005fto_005funicode_005f4z4z-81"></a></var><br> <blockquote><p><var>input</var>: zero-terminated Unicode string. <p><var>output</var>: pointer to newly allocated output Unicode string. <p><var>flags</var>: an <code>Idna_flags</code> value, e.g., <code>IDNA_ALLOW_UNASSIGNED</code> or <code>IDNA_USE_STD3_ASCII_RULES</code>. <p>Convert possibly ACE encoded domain name in UCS-4 format into a UCS-4 string. The domain name may contain several labels, separated by dots. The output buffer must be deallocated by the caller. <p><strong>Return value:</strong> Returns <code>IDNA_SUCCESS</code> on success, or error code. </p></blockquote></div> <h4 class="subheading">idna_to_unicode_8z4z</h4> <p><a name="idna_005fto_005funicode_005f8z4z"></a> <div class="defun"> — Function: int <b>idna_to_unicode_8z4z</b> (<var>const char * input, uint32_t ** output, int flags</var>)<var><a name="index-idna_005fto_005funicode_005f8z4z-82"></a></var><br> <blockquote><p><var>input</var>: zero-terminated UTF-8 string. <p><var>output</var>: pointer to newly allocated output Unicode string. <p><var>flags</var>: an <code>Idna_flags</code> value, e.g., <code>IDNA_ALLOW_UNASSIGNED</code> or <code>IDNA_USE_STD3_ASCII_RULES</code>. <p>Convert possibly ACE encoded domain name in UTF-8 format into a UCS-4 string. The domain name may contain several labels, separated by dots. The output buffer must be deallocated by the caller. <p><strong>Return value:</strong> Returns <code>IDNA_SUCCESS</code> on success, or error code. </p></blockquote></div> <h4 class="subheading">idna_to_unicode_8z8z</h4> <p><a name="idna_005fto_005funicode_005f8z8z"></a> <div class="defun"> — Function: int <b>idna_to_unicode_8z8z</b> (<var>const char * input, char ** output, int flags</var>)<var><a name="index-idna_005fto_005funicode_005f8z8z-83"></a></var><br> <blockquote><p><var>input</var>: zero-terminated UTF-8 string. <p><var>output</var>: pointer to newly allocated output UTF-8 string. <p><var>flags</var>: an <code>Idna_flags</code> value, e.g., <code>IDNA_ALLOW_UNASSIGNED</code> or <code>IDNA_USE_STD3_ASCII_RULES</code>. <p>Convert possibly ACE encoded domain name in UTF-8 format into a UTF-8 string. The domain name may contain several labels, separated by dots. The output buffer must be deallocated by the caller. <p><strong>Return value:</strong> Returns <code>IDNA_SUCCESS</code> on success, or error code. </p></blockquote></div> <h4 class="subheading">idna_to_unicode_8zlz</h4> <p><a name="idna_005fto_005funicode_005f8zlz"></a> <div class="defun"> — Function: int <b>idna_to_unicode_8zlz</b> (<var>const char * input, char ** output, int flags</var>)<var><a name="index-idna_005fto_005funicode_005f8zlz-84"></a></var><br> <blockquote><p><var>input</var>: zero-terminated UTF-8 string. <p><var>output</var>: pointer to newly allocated output string encoded in the current locale's character set. <p><var>flags</var>: an <code>Idna_flags</code> value, e.g., <code>IDNA_ALLOW_UNASSIGNED</code> or <code>IDNA_USE_STD3_ASCII_RULES</code>. <p>Convert possibly ACE encoded domain name in UTF-8 format into a string encoded in the current locale's character set. The domain name may contain several labels, separated by dots. The output buffer must be deallocated by the caller. <p><strong>Return value:</strong> Returns <code>IDNA_SUCCESS</code> on success, or error code. </p></blockquote></div> <h4 class="subheading">idna_to_unicode_lzlz</h4> <p><a name="idna_005fto_005funicode_005flzlz"></a> <div class="defun"> — Function: int <b>idna_to_unicode_lzlz</b> (<var>const char * input, char ** output, int flags</var>)<var><a name="index-idna_005fto_005funicode_005flzlz-85"></a></var><br> <blockquote><p><var>input</var>: zero-terminated string encoded in the current locale's character set. <p><var>output</var>: pointer to newly allocated output string encoded in the current locale's character set. <p><var>flags</var>: an <code>Idna_flags</code> value, e.g., <code>IDNA_ALLOW_UNASSIGNED</code> or <code>IDNA_USE_STD3_ASCII_RULES</code>. <p>Convert possibly ACE encoded domain name in the locale's character set into a string encoded in the current locale's character set. The domain name may contain several labels, separated by dots. The output buffer must be deallocated by the caller. <p><strong>Return value:</strong> Returns <code>IDNA_SUCCESS</code> on success, or error code. </p></blockquote></div> <h3 class="section">6.7 Error Handling</h3> <h4 class="subheading">idna_strerror</h4> <p><a name="idna_005fstrerror"></a> <div class="defun"> — Function: const char * <b>idna_strerror</b> (<var>Idna_rc rc</var>)<var><a name="index-idna_005fstrerror-86"></a></var><br> <blockquote><p><var>rc</var>: an <code>Idna_rc</code> return code. <p>Convert a return code integer to a text string. This string can be used to output a diagnostic message to the user. <p><strong>IDNA_SUCCESS:</strong> Successful operation. This value is guaranteed to always be zero, the remaining ones are only guaranteed to hold non-zero values, for logical comparison purposes. <p><strong>IDNA_STRINGPREP_ERROR:</strong> Error during string preparation. <p><strong>IDNA_PUNYCODE_ERROR:</strong> Error during punycode operation. <p><strong>IDNA_CONTAINS_NON_LDH:</strong> For IDNA_USE_STD3_ASCII_RULES, indicate that the string contains non-LDH ASCII characters. <p><strong>IDNA_CONTAINS_MINUS:</strong> For IDNA_USE_STD3_ASCII_RULES, indicate that the string contains a leading or trailing hyphen-minus (U+002D). <p><strong>IDNA_INVALID_LENGTH:</strong> The final output string is not within the (inclusive) range 1 to 63 characters. <p><strong>IDNA_NO_ACE_PREFIX:</strong> The string does not contain the ACE prefix (for ToUnicode). <p><strong>IDNA_ROUNDTRIP_VERIFY_ERROR:</strong> The ToASCII operation on output string does not equal the input. <p><strong>IDNA_CONTAINS_ACE_PREFIX:</strong> The input contains the ACE prefix (for ToASCII). <p><strong>IDNA_ICONV_ERROR:</strong> Could not convert string in locale encoding. <p><strong>IDNA_MALLOC_ERROR:</strong> Could not allocate buffer (this is typically a fatal error). <p><strong>IDNA_DLOPEN_ERROR:</strong> Could not dlopen the libcidn DSO (only used internally in libc). <p><strong>Return value:</strong> Returns a pointer to a statically allocated string containing a description of the error with the return code <code>rc</code>. </p></blockquote></div> <!-- ********************************************************** --> <!-- ********************** TLD Functions ********************* --> <!-- ********************************************************** --> <div class="node"> <p><hr> <a name="TLD-Functions"></a> Next: <a rel="next" accesskey="n" href="#PR29-Functions">PR29 Functions</a>, Previous: <a rel="previous" accesskey="p" href="#IDNA-Functions">IDNA Functions</a>, Up: <a rel="up" accesskey="u" href="#Top">Top</a> </div> <h2 class="chapter">7 TLD Functions</h2> <p><a name="index-TLD-Functions-87"></a> Organizations that manage some Top Level Domains (<acronym>TLD</acronym>s) have published tables with characters they accept within the domain. The reason may be to reduce complexity that come from using the full Unicode range, and to protect themselves from future (backwards incompatible) changes in the IDN or Unicode specifications. Libidn implement an infrastructure for defining and checking strings against such tables. Libidn also ship some tables from <acronym>TLD</acronym>s that we have managed to get permission to use them from. Because these tables are even less static than Unicode or StringPrep tables, it is likely that they will be updated from time to time (even in backwards incompatibe ways). The Libidn interface provide a “version” field for each <acronym>TLD</acronym> table, which can be compared for equality to guarantee the same operation over time. <p>From a design point of view, you can regard the <acronym>TLD</acronym> tables for IDN as the “localization” step that come after the “internationalization” step provided by the IETF standards. <p>The TLD functionality rely on up-to-date tables. The latest version of Libidn aim to provide these, but tables with unclear copying conditions, or generally experimental tables, are not included. Some such tables can be found at <a href="http://tldchk.berlios.de">http://tldchk.berlios.de</a>. <h3 class="section">7.1 Header file <code>tld.h</code></h3> <p>To use the functions explained in this chapter, you need to include the file <samp><span class="file">tld.h</span></samp> using: <pre class="example"> #include <tld.h> </pre> <!-- @section Data Types --> <!-- @deftp {Data type} {Tld_table_element} @var{start} @var{end} --> <!-- @example --> <!-- /* Interval of valid code points in the TLD. */ --> <!-- struct Tld_table_element --> <!-- @{ --> <!-- uint32_t start; /* Start of range. */ --> <!-- uint32_t end; /* End of range, end == start if single. */ --> <!-- @}; --> <!-- typedef struct Tld_table_element Tld_table_element; --> <!-- @end example --> <!-- This @code{struct} contain the @var{start} and @var{end} positions --> <!-- (inclusive) of a range. If the range is a single (i.e., starts and --> <!-- ends in the same character), then set @var{end} to the same as --> <!-- @var{start}. This structure is normally used as an array. --> <!-- @end deftp --> <!-- @deftp {Data type} {Tld_table} @var{name} @var{version} @var{nvalid} @var{valid} --> <!-- @example --> <!-- /* List valid code points in a TLD. */ --> <!-- struct Tld_table --> <!-- @{ --> <!-- char *name; /* TLD name, e.g., "no". */ --> <!-- char *version; /* Version string from TLD file. */ --> <!-- size_t nvalid; /* Number of entries in data. */ --> <!-- Tld_table_element *valid[]; /* Sorted array of valid code points. */ --> <!-- @}; --> <!-- typedef struct Tld_table Tld_table; --> <!-- @end example --> <!-- In this @code{struct}, the @var{name} field is a string (@samp{char*}) --> <!-- indicating the TLD name (e.g., ``no''). The @var{version} field is a --> <!-- string (@samp{char*}) containing a free form humanly readable string --> <!-- that can be used for equality comparison to compare different versions --> <!-- of the table. The @var{nvalid} field indicate how many entries there --> <!-- are in @var{valid}, which brings us finally to @var{valid} that --> <!-- contain the actual code points that are valid for this TLD (see --> <!-- @code{Tld_table_element} above). --> <!-- @end deftp --> <h3 class="section">7.2 Core Functions</h3> <h4 class="subheading">tld_check_4t</h4> <p><a name="tld_005fcheck_005f4t"></a> <div class="defun"> — Function: int <b>tld_check_4t</b> (<var>const uint32_t * in, size_t inlen, size_t * errpos, const Tld_table * tld</var>)<var><a name="index-tld_005fcheck_005f4t-88"></a></var><br> <blockquote><p><var>in</var>: Array of unicode code points to process. Does not need to be zero terminated. <p><var>inlen</var>: Number of unicode code points. <p><var>errpos</var>: Position of offending character is returned here. <p><var>tld</var>: A <code>Tld_table</code> data structure representing the restrictions for which the input should be tested. <p>Test each of the code points in <code>in</code> for whether or not they are allowed by the data structure in <code>tld</code>, return the position of the first character for which this is not the case in <code>errpos</code>. <p><strong>Return value:</strong> Returns the <code>Tld_rc</code> value <code>TLD_SUCCESS</code> if all code points are valid or when <code>tld</code> is null, <code>TLD_INVALID</code> if a character is not allowed, or additional error codes on general failure conditions. </p></blockquote></div> <h4 class="subheading">tld_check_4tz</h4> <p><a name="tld_005fcheck_005f4tz"></a> <div class="defun"> — Function: int <b>tld_check_4tz</b> (<var>const uint32_t * in, size_t * errpos, const Tld_table * tld</var>)<var><a name="index-tld_005fcheck_005f4tz-89"></a></var><br> <blockquote><p><var>in</var>: Zero terminated array of unicode code points to process. <p><var>errpos</var>: Position of offending character is returned here. <p><var>tld</var>: A <code>Tld_table</code> data structure representing the restrictions for which the input should be tested. <p>Test each of the code points in <code>in</code> for whether or not they are allowed by the data structure in <code>tld</code>, return the position of the first character for which this is not the case in <code>errpos</code>. <p><strong>Return value:</strong> Returns the <code>Tld_rc</code> value <code>TLD_SUCCESS</code> if all code points are valid or when <code>tld</code> is null, <code>TLD_INVALID</code> if a character is not allowed, or additional error codes on general failure conditions. </p></blockquote></div> <h3 class="section">7.3 Utility Functions</h3> <h4 class="subheading">tld_get_4</h4> <p><a name="tld_005fget_005f4"></a> <div class="defun"> — Function: int <b>tld_get_4</b> (<var>const uint32_t * in, size_t inlen, char ** out</var>)<var><a name="index-tld_005fget_005f4-90"></a></var><br> <blockquote><p><var>in</var>: Array of unicode code points to process. Does not need to be zero terminated. <p><var>inlen</var>: Number of unicode code points. <p><var>out</var>: Zero terminated ascii result string pointer. <p>Isolate the top-level domain of <code>in</code> and return it as an ASCII string in <code>out</code>. <p><strong>Return value:</strong> Return <code>TLD_SUCCESS</code> on success, or the corresponding <code>Tld_rc</code> error code otherwise. </p></blockquote></div> <h4 class="subheading">tld_get_4z</h4> <p><a name="tld_005fget_005f4z"></a> <div class="defun"> — Function: int <b>tld_get_4z</b> (<var>const uint32_t * in, char ** out</var>)<var><a name="index-tld_005fget_005f4z-91"></a></var><br> <blockquote><p><var>in</var>: Zero terminated array of unicode code points to process. <p><var>out</var>: Zero terminated ascii result string pointer. <p>Isolate the top-level domain of <code>in</code> and return it as an ASCII string in <code>out</code>. <p><strong>Return value:</strong> Return <code>TLD_SUCCESS</code> on success, or the corresponding <code>Tld_rc</code> error code otherwise. </p></blockquote></div> <h4 class="subheading">tld_get_z</h4> <p><a name="tld_005fget_005fz"></a> <div class="defun"> — Function: int <b>tld_get_z</b> (<var>const char * in, char ** out</var>)<var><a name="index-tld_005fget_005fz-92"></a></var><br> <blockquote><p><var>in</var>: Zero terminated character array to process. <p><var>out</var>: Zero terminated ascii result string pointer. <p>Isolate the top-level domain of <code>in</code> and return it as an ASCII string in <code>out</code>. The input string <code>in</code> may be UTF-8, ISO-8859-1 or any ASCII compatible character encoding. <p><strong>Return value:</strong> Return <code>TLD_SUCCESS</code> on success, or the corresponding <code>Tld_rc</code> error code otherwise. </p></blockquote></div> <h4 class="subheading">tld_get_table</h4> <p><a name="tld_005fget_005ftable"></a> <div class="defun"> — Function: const Tld_table * <b>tld_get_table</b> (<var>const char * tld, const Tld_table ** tables</var>)<var><a name="index-tld_005fget_005ftable-93"></a></var><br> <blockquote><p><var>tld</var>: TLD name (e.g. "com") as zero terminated ASCII byte string. <p><var>tables</var>: Zero terminated array of <code>Tld_table</code> info-structures for TLDs. <p>Get the TLD table for a named TLD by searching through the given TLD table array. <p><strong>Return value:</strong> Return structure corresponding to TLD <code>tld</code> by going thru <code>tables</code>, or return <code>NULL</code> if no such structure is found. </p></blockquote></div> <h4 class="subheading">tld_default_table</h4> <p><a name="tld_005fdefault_005ftable"></a> <div class="defun"> — Function: const Tld_table * <b>tld_default_table</b> (<var>const char * tld, const Tld_table ** overrides</var>)<var><a name="index-tld_005fdefault_005ftable-94"></a></var><br> <blockquote><p><var>tld</var>: TLD name (e.g. "com") as zero terminated ASCII byte string. <p><var>overrides</var>: Additional zero terminated array of <code>Tld_table</code> info-structures for TLDs, or <code>NULL</code> to only use library deault tables. <p>Get the TLD table for a named TLD, using the internal defaults, possibly overrided by the (optional) supplied tables. <p><strong>Return value:</strong> Return structure corresponding to TLD <code>tld_str</code>, first looking through <code>overrides</code> then thru built-in list, or <code>NULL</code> if no such structure found. </p></blockquote></div> <h3 class="section">7.4 High-Level Wrapper Functions</h3> <h4 class="subheading">tld_check_4</h4> <p><a name="tld_005fcheck_005f4"></a> <div class="defun"> — Function: int <b>tld_check_4</b> (<var>const uint32_t * in, size_t inlen, size_t * errpos, const Tld_table ** overrides</var>)<var><a name="index-tld_005fcheck_005f4-95"></a></var><br> <blockquote><p><var>in</var>: Array of unicode code points to process. Does not need to be zero terminated. <p><var>inlen</var>: Number of unicode code points. <p><var>errpos</var>: Position of offending character is returned here. <p><var>overrides</var>: A <code>Tld_table</code> array of additional domain restriction structures that complement and supersede the built-in information. <p>Test each of the code points in <code>in</code> for whether or not they are allowed by the information in <code>overrides</code> or by the built-in TLD restriction data. When data for the same TLD is available both internally and in <code>overrides</code>, the information in <code>overrides</code> takes precedence. If several entries for a specific TLD are found, the first one is used. If <code>overrides</code> is <code>NULL</code>, only the built-in information is used. The position of the first offending character is returned in <code>errpos</code>. <p><strong>Return value:</strong> Returns the <code>Tld_rc</code> value <code>TLD_SUCCESS</code> if all code points are valid or when <code>tld</code> is null, <code>TLD_INVALID</code> if a character is not allowed, or additional error codes on general failure conditions. </p></blockquote></div> <h4 class="subheading">tld_check_4z</h4> <p><a name="tld_005fcheck_005f4z"></a> <div class="defun"> — Function: int <b>tld_check_4z</b> (<var>const uint32_t * in, size_t * errpos, const Tld_table ** overrides</var>)<var><a name="index-tld_005fcheck_005f4z-96"></a></var><br> <blockquote><p><var>in</var>: Zero-terminated array of unicode code points to process. <p><var>errpos</var>: Position of offending character is returned here. <p><var>overrides</var>: A <code>Tld_table</code> array of additional domain restriction structures that complement and supersede the built-in information. <p>Test each of the code points in <code>in</code> for whether or not they are allowed by the information in <code>overrides</code> or by the built-in TLD restriction data. When data for the same TLD is available both internally and in <code>overrides</code>, the information in <code>overrides</code> takes precedence. If several entries for a specific TLD are found, the first one is used. If <code>overrides</code> is <code>NULL</code>, only the built-in information is used. The position of the first offending character is returned in <code>errpos</code>. <p><strong>Return value:</strong> Returns the <code>Tld_rc</code> value <code>TLD_SUCCESS</code> if all code points are valid or when <code>tld</code> is null, <code>TLD_INVALID</code> if a character is not allowed, or additional error codes on general failure conditions. </p></blockquote></div> <h4 class="subheading">tld_check_8z</h4> <p><a name="tld_005fcheck_005f8z"></a> <div class="defun"> — Function: int <b>tld_check_8z</b> (<var>const char * in, size_t * errpos, const Tld_table ** overrides</var>)<var><a name="index-tld_005fcheck_005f8z-97"></a></var><br> <blockquote><p><var>in</var>: Zero-terminated UTF8 string to process. <p><var>errpos</var>: Position of offending character is returned here. <p><var>overrides</var>: A <code>Tld_table</code> array of additional domain restriction structures that complement and supersede the built-in information. <p>Test each of the characters in <code>in</code> for whether or not they are allowed by the information in <code>overrides</code> or by the built-in TLD restriction data. When data for the same TLD is available both internally and in <code>overrides</code>, the information in <code>overrides</code> takes precedence. If several entries for a specific TLD are found, the first one is used. If <code>overrides</code> is <code>NULL</code>, only the built-in information is used. The position of the first offending character is returned in <code>errpos</code>. Note that the error position refers to the decoded character offset rather than the byte position in the string. <p><strong>Return value:</strong> Returns the <code>Tld_rc</code> value <code>TLD_SUCCESS</code> if all characters are valid or when <code>tld</code> is null, <code>TLD_INVALID</code> if a character is not allowed, or additional error codes on general failure conditions. </p></blockquote></div> <h4 class="subheading">tld_check_lz</h4> <p><a name="tld_005fcheck_005flz"></a> <div class="defun"> — Function: int <b>tld_check_lz</b> (<var>const char * in, size_t * errpos, const Tld_table ** overrides</var>)<var><a name="index-tld_005fcheck_005flz-98"></a></var><br> <blockquote><p><var>in</var>: Zero-terminated string in the current locales encoding to process. <p><var>errpos</var>: Position of offending character is returned here. <p><var>overrides</var>: A <code>Tld_table</code> array of additional domain restriction structures that complement and supersede the built-in information. <p>Test each of the characters in <code>in</code> for whether or not they are allowed by the information in <code>overrides</code> or by the built-in TLD restriction data. When data for the same TLD is available both internally and in <code>overrides</code>, the information in <code>overrides</code> takes precedence. If several entries for a specific TLD are found, the first one is used. If <code>overrides</code> is <code>NULL</code>, only the built-in information is used. The position of the first offending character is returned in <code>errpos</code>. Note that the error position refers to the decoded character offset rather than the byte position in the string. <p><strong>Return value:</strong> Returns the <code>Tld_rc</code> value <code>TLD_SUCCESS</code> if all characters are valid or when <code>tld</code> is null, <code>TLD_INVALID</code> if a character is not allowed, or additional error codes on general failure conditions. </p></blockquote></div> <h3 class="section">7.5 Error Handling</h3> <h4 class="subheading">tld_strerror</h4> <p><a name="tld_005fstrerror"></a> <div class="defun"> — Function: const char * <b>tld_strerror</b> (<var>Tld_rc rc</var>)<var><a name="index-tld_005fstrerror-99"></a></var><br> <blockquote><p><var>rc</var>: tld return code <p>Convert a return code integer to a text string. This string can be used to output a diagnostic message to the user. <p><strong>TLD_SUCCESS:</strong> Successful operation. This value is guaranteed to always be zero, the remaining ones are only guaranteed to hold non-zero values, for logical comparison purposes. <p><strong>TLD_INVALID:</strong> Invalid character found. <p><strong>TLD_NODATA:</strong> No input data was provided. <p><strong>TLD_MALLOC_ERROR:</strong> Error during memory allocation. <p><strong>TLD_ICONV_ERROR:</strong> Error during iconv string conversion. <p><strong>TLD_NO_TLD:</strong> No top-level domain found in domain string. <p><strong>Return value:</strong> Returns a pointer to a statically allocated string containing a description of the error with the return code <code>rc</code>. </p></blockquote></div> <!-- ********************************************************** --> <!-- ********************** PR29 Functions ******************** --> <!-- ********************************************************** --> <div class="node"> <p><hr> <a name="PR29-Functions"></a> Next: <a rel="next" accesskey="n" href="#Examples">Examples</a>, Previous: <a rel="previous" accesskey="p" href="#TLD-Functions">TLD Functions</a>, Up: <a rel="up" accesskey="u" href="#Top">Top</a> </div> <h2 class="chapter">8 PR29 Functions</h2> <p><a name="index-PR29-Functions-100"></a> A deficiency in the specification of Unicode Normalization Forms has been found. The consequence is that some strings can be normalized into different strings by different implementations. In other words, two different implementations may return different output for the same input (because the interpretation of the specification is ambiguous). Further, an implementation invoked again on the one of the output strings may return a different string (because one of the interpretation of the ambiguous specification make normalization non-idempotent). Fortunately, only a select few character sequence exhibit this problem, and none of them are expected to occur in natural languages (due to different linguistic uses of the involved characters). <p>A full discussion of the problem may be found at: <p><a href="http://www.unicode.org/review/pr-29.html">http://www.unicode.org/review/pr-29.html</a> <p>The PR29 functions below allow you to detect the problem sequence. So when would you want to use these functions? For most applications, such as those using Nameprep for IDN, this is likely only to be an interoperability problem. Thus, you may not want to care about it, as the character sequences will rarely occur naturally. However, if you are using a profile, such as SASLPrep, to process authentication tokens; authorization tokens; or passwords, there is a real danger that attackers may try to use the peculiarities in these strings to attack parts of your system. As only a small number of strings, and no naturally occurring strings, exhibit this problem, the conservative approach of rejecting the strings is recommended. If this approach is not used, you should instead verify that all parts of your system, that process the tokens and passwords, use a NFKC implementation that produce the same output for the same input. <p>Technically inclined readers may be interested in knowing more about the implementation aspects of the PR29 flaw. See <a href="#PR29-discussion">PR29 discussion</a>. <h3 class="section">8.1 Header file <code>pr29.h</code></h3> <p>To use the functions explained in this chapter, you need to include the file <samp><span class="file">pr29.h</span></samp> using: <pre class="example"> #include <pr29.h> </pre> <h3 class="section">8.2 Core Functions</h3> <h4 class="subheading">pr29_4</h4> <p><a name="pr29_005f4"></a> <div class="defun"> — Function: int <b>pr29_4</b> (<var>const uint32_t * in, size_t len</var>)<var><a name="index-pr29_005f4-101"></a></var><br> <blockquote><p><var>in</var>: input array with unicode code points. <p><var>len</var>: length of input array with unicode code points. <p>Check the input to see if it may be normalized into different strings by different NFKC implementations, due to an anomaly in the NFKC specifications. <p><strong>Return value:</strong> Returns the <code>Pr29_rc</code> value <code>PR29_SUCCESS</code> on success, and <code>PR29_PROBLEM</code> if the input sequence is a "problem sequence" (i.e., may be normalized into different strings by different implementations). </p></blockquote></div> <h3 class="section">8.3 Utility Functions</h3> <h4 class="subheading">pr29_4z</h4> <p><a name="pr29_005f4z"></a> <div class="defun"> — Function: int <b>pr29_4z</b> (<var>const uint32_t * in</var>)<var><a name="index-pr29_005f4z-102"></a></var><br> <blockquote><p><var>in</var>: zero terminated array of Unicode code points. <p>Check the input to see if it may be normalized into different strings by different NFKC implementations, due to an anomaly in the NFKC specifications. <p><strong>Return value:</strong> Returns the <code>Pr29_rc</code> value <code>PR29_SUCCESS</code> on success, and <code>PR29_PROBLEM</code> if the input sequence is a "problem sequence" (i.e., may be normalized into different strings by different implementations). </p></blockquote></div> <h4 class="subheading">pr29_8z</h4> <p><a name="pr29_005f8z"></a> <div class="defun"> — Function: int <b>pr29_8z</b> (<var>const char * in</var>)<var><a name="index-pr29_005f8z-103"></a></var><br> <blockquote><p><var>in</var>: zero terminated input UTF-8 string. <p>Check the input to see if it may be normalized into different strings by different NFKC implementations, due to an anomaly in the NFKC specifications. <p><strong>Return value:</strong> Returns the <code>Pr29_rc</code> value <code>PR29_SUCCESS</code> on success, and <code>PR29_PROBLEM</code> if the input sequence is a "problem sequence" (i.e., may be normalized into different strings by different implementations), or <code>PR29_STRINGPREP_ERROR</code> if there was a problem converting the string from UTF-8 to UCS-4. </p></blockquote></div> <h3 class="section">8.4 Error Handling</h3> <h4 class="subheading">pr29_strerror</h4> <p><a name="pr29_005fstrerror"></a> <div class="defun"> — Function: const char * <b>pr29_strerror</b> (<var>Pr29_rc rc</var>)<var><a name="index-pr29_005fstrerror-104"></a></var><br> <blockquote><p><var>rc</var>: an <code>Pr29_rc</code> return code. <p>Convert a return code integer to a text string. This string can be used to output a diagnostic message to the user. <p><strong>PR29_SUCCESS:</strong> Successful operation. This value is guaranteed to always be zero, the remaining ones are only guaranteed to hold non-zero values, for logical comparison purposes. <p><strong>PR29_PROBLEM:</strong> A problem sequence was encountered. <p><strong>PR29_STRINGPREP_ERROR:</strong> The character set conversion failed (only for <code>pr29_8()</code> and <code>pr29_8z()</code>). <p><strong>Return value:</strong> Returns a pointer to a statically allocated string containing a description of the error with the return code <code>rc</code>. </p></blockquote></div> <!-- ********************************************************** --> <!-- *********************** Examples *********************** --> <!-- ********************************************************** --> <div class="node"> <p><hr> <a name="Examples"></a> Next: <a rel="next" accesskey="n" href="#Invoking-idn">Invoking idn</a>, Previous: <a rel="previous" accesskey="p" href="#PR29-Functions">PR29 Functions</a>, Up: <a rel="up" accesskey="u" href="#Top">Top</a> </div> <h2 class="chapter">9 Examples</h2> <p><a name="index-Examples-105"></a> This chapter contains example code which illustrate how `Libidn' can be used when writing your own application. <ul class="menu"> <li><a accesskey="1" href="#Example-1">Example 1</a>: Example using stringprep. <li><a accesskey="2" href="#Example-2">Example 2</a>: Example using punycode. <li><a accesskey="3" href="#Example-3">Example 3</a>: Example using IDNA ToASCII. <li><a accesskey="4" href="#Example-4">Example 4</a>: Example using IDNA ToUnicode. <li><a accesskey="5" href="#Example-5">Example 5</a>: Example using TLD checking. </ul> <div class="node"> <p><hr> <a name="Example-1"></a> Next: <a rel="next" accesskey="n" href="#Example-2">Example 2</a>, Up: <a rel="up" accesskey="u" href="#Examples">Examples</a> </div> <h3 class="section">9.1 Example 1</h3> <p>This example demonstrates how the stringprep functions are used. <pre class="verbatim">/* example.c --- Example code showing how to use stringprep(). * Copyright (C) 2002, 2003, 2004, 2005, 2006, 2007 Simon Josefsson * * This file is part of GNU Libidn. * * GNU Libidn is free software; you can redistribute it and/or * modify it under the terms of the GNU Lesser General Public * License as published by the Free Software Foundation; either * version 2.1 of the License, or (at your option) any later version. * * GNU Libidn is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU * Lesser General Public License for more details. * * You should have received a copy of the GNU Lesser General Public * License along with GNU Libidn; if not, write to the Free Software * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA * */ #include <stdio.h> #include <stdlib.h> #include <string.h> #include <locale.h> /* setlocale() */ #include <stringprep.h> /* * Compiling using libtool and pkg-config is recommended: * * $ libtool cc -o example example.c `pkg-config --cflags --libs libidn` * $ ./example * Input string encoded as `ISO-8859-1': ª * Before locale2utf8 (length 2): aa 0a * Before stringprep (length 3): c2 aa 0a * After stringprep (length 2): 61 0a * $ * */ int main (int argc, char *argv[]) { char buf[BUFSIZ]; char *p; int rc; size_t i; setlocale (LC_ALL, ""); printf ("Input string encoded as `%s': ", stringprep_locale_charset ()); fflush (stdout); fgets (buf, BUFSIZ, stdin); printf ("Before locale2utf8 (length %d): ", strlen (buf)); for (i = 0; i < strlen (buf); i++) printf ("%02x ", buf[i] & 0xFF); printf ("\n"); p = stringprep_locale_to_utf8 (buf); if (p) { strcpy (buf, p); free (p); } else printf ("Could not convert string to UTF-8, continuing anyway...\n"); printf ("Before stringprep (length %d): ", strlen (buf)); for (i = 0; i < strlen (buf); i++) printf ("%02x ", buf[i] & 0xFF); printf ("\n"); rc = stringprep (buf, BUFSIZ, 0, stringprep_nameprep); if (rc != STRINGPREP_OK) printf ("Stringprep failed (%d): %s\n", rc, stringprep_strerror (rc)); else { printf ("After stringprep (length %d): ", strlen (buf)); for (i = 0; i < strlen (buf); i++) printf ("%02x ", buf[i] & 0xFF); printf ("\n"); } return 0; } </pre> <div class="node"> <p><hr> <a name="Example-2"></a> Next: <a rel="next" accesskey="n" href="#Example-3">Example 3</a>, Previous: <a rel="previous" accesskey="p" href="#Example-1">Example 1</a>, Up: <a rel="up" accesskey="u" href="#Examples">Examples</a> </div> <h3 class="section">9.2 Example 2</h3> <p>This example demonstrates how the punycode functions are used. <pre class="verbatim">/* example2.c --- Example code showing how to use punycode. * Copyright (C) 2002, 2003, 2004, 2005, 2006, 2007 Simon Josefsson * Copyright (C) 2002 Adam M. Costello * * This file is part of GNU Libidn. * * GNU Libidn is free software; you can redistribute it and/or * modify it under the terms of the GNU Lesser General Public * License as published by the Free Software Foundation; either * version 2.1 of the License, or (at your option) any later version. * * GNU Libidn is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU * Lesser General Public License for more details. * * You should have received a copy of the GNU Lesser General Public * License along with GNU Libidn; if not, write to the Free Software * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA * */ #include <locale.h> /* setlocale() */ /* * This file is derived from RFC 3492 written by Adam M. Costello. * * Disclaimer and license: Regarding this entire document or any * portion of it (including the pseudocode and C code), the author * makes no guarantees and is not responsible for any damage resulting * from its use. The author grants irrevocable permission to anyone * to use, modify, and distribute it in any way that does not diminish * the rights of anyone else to use, modify, and distribute it, * provided that redistributed derivative works do not contain * misleading author or version information. Derivative works need * not be licensed under similar terms. * */ #include <assert.h> #include <stdio.h> #include <stdlib.h> #include <string.h> #include <punycode.h> /* For testing, we'll just set some compile-time limits rather than */ /* use malloc(), and set a compile-time option rather than using a */ /* command-line option. */ enum { unicode_max_length = 256, ace_max_length = 256 }; static void usage (char **argv) { fprintf (stderr, "\n" "%s -e reads code points and writes a Punycode string.\n" "%s -d reads a Punycode string and writes code points.\n" "\n" "Input and output are plain text in the native character set.\n" "Code points are in the form u+hex separated by whitespace.\n" "Although the specification allows Punycode strings to contain\n" "any characters from the ASCII repertoire, this test code\n" "supports only the printable characters, and needs the Punycode\n" "string to be followed by a newline.\n" "The case of the u in u+hex is the force-to-uppercase flag.\n", argv[0], argv[0]); exit (EXIT_FAILURE); } static void fail (const char *msg) { fputs (msg, stderr); exit (EXIT_FAILURE); } static const char too_big[] = "input or output is too large, recompile with larger limits\n"; static const char invalid_input[] = "invalid input\n"; static const char overflow[] = "arithmetic overflow\n"; static const char io_error[] = "I/O error\n"; /* The following string is used to convert printable */ /* characters between ASCII and the native charset: */ static const char print_ascii[] = "\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n" "\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n" " !\"#$%&'()*+,-./" "0123456789:;<=>?" "\0x40" /* at sign */ "ABCDEFGHIJKLMNO" "PQRSTUVWXYZ[\\]^_" "`abcdefghijklmno" "pqrstuvwxyz{|}~\n"; int main (int argc, char **argv) { enum punycode_status status; int r; size_t input_length, output_length, j; unsigned char case_flags[unicode_max_length]; setlocale (LC_ALL, ""); if (argc != 2) usage (argv); if (argv[1][0] != '-') usage (argv); if (argv[1][2] != 0) usage (argv); if (argv[1][1] == 'e') { uint32_t input[unicode_max_length]; unsigned long codept; char output[ace_max_length + 1], uplus[3]; int c; /* Read the input code points: */ input_length = 0; for (;;) { r = scanf ("%2s%lx", uplus, &codept); if (ferror (stdin)) fail (io_error); if (r == EOF || r == 0) break; if (r != 2 || uplus[1] != '+' || codept > (uint32_t) - 1) { fail (invalid_input); } if (input_length == unicode_max_length) fail (too_big); if (uplus[0] == 'u') case_flags[input_length] = 0; else if (uplus[0] == 'U') case_flags[input_length] = 1; else fail (invalid_input); input[input_length++] = codept; } /* Encode: */ output_length = ace_max_length; status = punycode_encode (input_length, input, case_flags, &output_length, output); if (status == punycode_bad_input) fail (invalid_input); if (status == punycode_big_output) fail (too_big); if (status == punycode_overflow) fail (overflow); assert (status == punycode_success); /* Convert to native charset and output: */ for (j = 0; j < output_length; ++j) { c = output[j]; assert (c >= 0 && c <= 127); if (print_ascii[c] == 0) fail (invalid_input); output[j] = print_ascii[c]; } output[j] = 0; r = puts (output); if (r == EOF) fail (io_error); return EXIT_SUCCESS; } if (argv[1][1] == 'd') { char input[ace_max_length + 2], *p, *pp; uint32_t output[unicode_max_length]; /* Read the Punycode input string and convert to ASCII: */ fgets (input, ace_max_length + 2, stdin); if (ferror (stdin)) fail (io_error); if (feof (stdin)) fail (invalid_input); input_length = strlen (input) - 1; if (input[input_length] != '\n') fail (too_big); input[input_length] = 0; for (p = input; *p != 0; ++p) { pp = strchr (print_ascii, *p); if (pp == 0) fail (invalid_input); *p = pp - print_ascii; } /* Decode: */ output_length = unicode_max_length; status = punycode_decode (input_length, input, &output_length, output, case_flags); if (status == punycode_bad_input) fail (invalid_input); if (status == punycode_big_output) fail (too_big); if (status == punycode_overflow) fail (overflow); assert (status == punycode_success); /* Output the result: */ for (j = 0; j < output_length; ++j) { r = printf ("%s+%04lX\n", case_flags[j] ? "U" : "u", (unsigned long) output[j]); if (r < 0) fail (io_error); } return EXIT_SUCCESS; } usage (argv); return EXIT_SUCCESS; /* not reached, but quiets compiler warning */ } </pre> <div class="node"> <p><hr> <a name="Example-3"></a> Next: <a rel="next" accesskey="n" href="#Example-4">Example 4</a>, Previous: <a rel="previous" accesskey="p" href="#Example-2">Example 2</a>, Up: <a rel="up" accesskey="u" href="#Examples">Examples</a> </div> <h3 class="section">9.3 Example 3</h3> <p>This example demonstrates how the library is used to convert internationalized domain names into ASCII compatible names. <pre class="verbatim">/* example3.c --- Example ToASCII() code showing how to use Libidn. * Copyright (C) 2002, 2003, 2004, 2005, 2006, 2007 Simon Josefsson * * This file is part of GNU Libidn. * * GNU Libidn is free software; you can redistribute it and/or * modify it under the terms of the GNU Lesser General Public * License as published by the Free Software Foundation; either * version 2.1 of the License, or (at your option) any later version. * * GNU Libidn is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU * Lesser General Public License for more details. * * You should have received a copy of the GNU Lesser General Public * License along with GNU Libidn; if not, write to the Free Software * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA * */ #include <stdio.h> #include <stdlib.h> #include <string.h> #include <locale.h> /* setlocale() */ #include <stringprep.h> /* stringprep_locale_charset() */ #include <idna.h> /* idna_to_ascii_lz() */ /* * Compiling using libtool and pkg-config is recommended: * * $ libtool cc -o example3 example3.c `pkg-config --cflags --libs libidn` * $ ./example3 * Input domain encoded as `ISO-8859-1': www.räksmörgåsª.example * Read string (length 23): 77 77 77 2e 72 e4 6b 73 6d f6 72 67 e5 73 aa 2e 65 78 61 6d 70 6c 65 * ACE label (length 33): 'www.xn--rksmrgsa-0zap8p.example' * 77 77 77 2e 78 6e 2d 2d 72 6b 73 6d 72 67 73 61 2d 30 7a 61 70 38 70 2e 65 78 61 6d 70 6c 65 * $ * */ int main (int argc, char *argv[]) { char buf[BUFSIZ]; char *p; int rc; size_t i; setlocale (LC_ALL, ""); printf ("Input domain encoded as `%s': ", stringprep_locale_charset ()); fflush (stdout); fgets (buf, BUFSIZ, stdin); buf[strlen (buf) - 1] = '\0'; printf ("Read string (length %d): ", strlen (buf)); for (i = 0; i < strlen (buf); i++) printf ("%02x ", buf[i] & 0xFF); printf ("\n"); rc = idna_to_ascii_lz (buf, &p, 0); if (rc != IDNA_SUCCESS) { printf ("ToASCII() failed (%d): %s\n", rc, idna_strerror (rc)); exit (1); } printf ("ACE label (length %d): '%s'\n", strlen (p), p); for (i = 0; i < strlen (p); i++) printf ("%02x ", p[i] & 0xFF); printf ("\n"); free (p); return 0; } </pre> <div class="node"> <p><hr> <a name="Example-4"></a> Next: <a rel="next" accesskey="n" href="#Example-5">Example 5</a>, Previous: <a rel="previous" accesskey="p" href="#Example-3">Example 3</a>, Up: <a rel="up" accesskey="u" href="#Examples">Examples</a> </div> <h3 class="section">9.4 Example 4</h3> <p>This example demonstrates how the library is used to convert ASCII compatible names to internationalized domain names. <pre class="verbatim">/* example4.c --- Example ToUnicode() code showing how to use Libidn. * Copyright (C) 2002, 2003, 2004, 2005, 2006, 2007 Simon Josefsson * * This file is part of GNU Libidn. * * GNU Libidn is free software; you can redistribute it and/or * modify it under the terms of the GNU Lesser General Public * License as published by the Free Software Foundation; either * version 2.1 of the License, or (at your option) any later version. * * GNU Libidn is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU * Lesser General Public License for more details. * * You should have received a copy of the GNU Lesser General Public * License along with GNU Libidn; if not, write to the Free Software * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA * */ #include <stdio.h> #include <stdlib.h> #include <string.h> #include <locale.h> /* setlocale() */ #include <stringprep.h> /* stringprep_locale_charset() */ #include <idna.h> /* idna_to_unicode_lzlz() */ /* * Compiling using libtool and pkg-config is recommended: * * $ libtool cc -o example4 example4.c `pkg-config --cflags --libs libidn` * $ ./example4 * Input domain encoded as `ISO-8859-1': www.xn--rksmrgsa-0zap8p.example * Read string (length 33): 77 77 77 2e 78 6e 2d 2d 72 6b 73 6d 72 67 73 61 2d 30 7a 61 70 38 70 2e 65 78 61 6d 70 6c 65 * ACE label (length 23): 'www.räksmörgåsa.example' * 77 77 77 2e 72 e4 6b 73 6d f6 72 67 e5 73 61 2e 65 78 61 6d 70 6c 65 * $ * */ int main (int argc, char *argv[]) { char buf[BUFSIZ]; char *p; int rc; size_t i; setlocale (LC_ALL, ""); printf ("Input domain encoded as `%s': ", stringprep_locale_charset ()); fflush (stdout); fgets (buf, BUFSIZ, stdin); buf[strlen (buf) - 1] = '\0'; printf ("Read string (length %d): ", strlen (buf)); for (i = 0; i < strlen (buf); i++) printf ("%02x ", buf[i] & 0xFF); printf ("\n"); rc = idna_to_unicode_lzlz (buf, &p, 0); if (rc != IDNA_SUCCESS) { printf ("ToUnicode() failed (%d): %s\n", rc, idna_strerror (rc)); exit (1); } printf ("ACE label (length %d): '%s'\n", strlen (p), p); for (i = 0; i < strlen (p); i++) printf ("%02x ", p[i] & 0xFF); printf ("\n"); free (p); return 0; } </pre> <div class="node"> <p><hr> <a name="Example-5"></a> Previous: <a rel="previous" accesskey="p" href="#Example-4">Example 4</a>, Up: <a rel="up" accesskey="u" href="#Examples">Examples</a> </div> <h3 class="section">9.5 Example 5</h3> <p>This example demonstrates how the library is used to check a string for invalid characters within a specific TLD. <pre class="verbatim">/* example5.c --- Example TLD checking. * Copyright (C) 2004, 2005, 2006, 2007 Simon Josefsson * * This file is part of GNU Libidn. * * GNU Libidn is free software; you can redistribute it and/or * modify it under the terms of the GNU Lesser General Public * License as published by the Free Software Foundation; either * version 2.1 of the License, or (at your option) any later version. * * GNU Libidn is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU * Lesser General Public License for more details. * * You should have received a copy of the GNU Lesser General Public * License along with GNU Libidn; if not, write to the Free Software * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA * */ #include <stdio.h> #include <stdlib.h> #include <string.h> /* Get stringprep_locale_charset, etc. */ #include <stringprep.h> /* Get idna_to_ascii_8z, etc. */ #include <idna.h> /* Get tld_check_4z. */ #include <tld.h> /* * Compiling using libtool and pkg-config is recommended: * * $ libtool cc -o example5 example5.c `pkg-config --cflags --libs libidn` * $ ./example5 * Input domain encoded as `UTF-8': fooß.no * Read string (length 8): 66 6f 6f c3 9f 2e 6e 6f * ToASCII string (length 8): fooss.no * ToUnicode string: U+0066 U+006f U+006f U+0073 U+0073 U+002e U+006e U+006f * Domain accepted by TLD check * * $ ./example5 * Input domain encoded as `UTF-8': gr€€n.no * Read string (length 12): 67 72 e2 82 ac e2 82 ac 6e 2e 6e 6f * ToASCII string (length 16): xn--grn-l50aa.no * ToUnicode string: U+0067 U+0072 U+20ac U+20ac U+006e U+002e U+006e U+006f * Domain rejected by TLD check, Unicode position 2 * */ int main (int argc, char *argv[]) { char buf[BUFSIZ]; char *p; uint32_t *r; int rc; size_t errpos, i; printf ("Input domain encoded as `%s': ", stringprep_locale_charset ()); fflush (stdout); fgets (buf, BUFSIZ, stdin); buf[strlen (buf) - 1] = '\0'; printf ("Read string (length %d): ", strlen (buf)); for (i = 0; i < strlen (buf); i++) printf ("%02x ", buf[i] & 0xFF); printf ("\n"); p = stringprep_locale_to_utf8 (buf); if (p) { strcpy (buf, p); free (p); } else printf ("Could not convert string to UTF-8, continuing anyway...\n"); rc = idna_to_ascii_8z (buf, &p, 0); if (rc != IDNA_SUCCESS) { printf ("idna_to_ascii_8z failed (%d): %s\n", rc, idna_strerror (rc)); return 2; } printf ("ToASCII string (length %d): %s\n", strlen (p), p); rc = idna_to_unicode_8z4z (p, &r, 0); free (p); if (rc != IDNA_SUCCESS) { printf ("idna_to_unicode_8z4z failed (%d): %s\n", rc, idna_strerror (rc)); return 2; } printf ("ToUnicode string: "); for (i = 0; r[i]; i++) printf ("U+%04x ", r[i]); printf ("\n"); rc = tld_check_4z (r, &errpos, NULL); free (r); if (rc == TLD_INVALID) { printf ("Domain rejected by TLD check, Unicode position %d\n", errpos); return 1; } else if (rc != TLD_SUCCESS) { printf ("tld_check_4z() failed (%d): %s\n", rc, tld_strerror (rc)); return 2; } printf ("Domain accepted by TLD check\n"); return 0; } </pre> <!-- ********************************************************** --> <!-- ********************* Invoking idn ********************* --> <!-- ********************************************************** --> <div class="node"> <p><hr> <a name="Invoking-idn"></a> Next: <a rel="next" accesskey="n" href="#Emacs-API">Emacs API</a>, Previous: <a rel="previous" accesskey="p" href="#Examples">Examples</a>, Up: <a rel="up" accesskey="u" href="#Top">Top</a> </div> <h2 class="chapter">10 Invoking idn</h2> <p><a name="index-idn-106"></a><a name="index-invoking-_0040command_007bidn_007d-107"></a><a name="index-command-line-108"></a> <h3 class="section">10.1 Name</h3> <p>GNU Libidn (idn) – Internationalized Domain Names command line tool <h3 class="section">10.2 Description</h3> <p><code>idn</code> allows internationalized string preparation (`<samp><span class="samp">stringprep</span></samp>'), encoding and decoding of punycode data, and IDNA ToASCII/ToUnicode operations to be performed on the command line. <p>If strings are specified on the command line, they are used as input and the computed output is printed to standard output <code>stdout</code>. If no strings are specified on the command line, the program read data, line by line, from the standard input <code>stdin</code>, and print the computed output to standard output. What processing is performed (e.g., ToASCII, or Punycode encode) is indicated by options. If any errors are encountered, the execution of the applications is aborted. <p>All strings are expected to be encoded in the preferred charset used by your locale. Use <code>--debug</code> to find out what this charset is. You can override the charset used by setting environment variable <code>CHARSET</code>. <p>To process a string that starts with <code>-</code>, for example <code>-foo</code>, use <code>--</code> to signal the end of parameters, as in <code>idn --quiet -a -- -foo</code>. <h3 class="section">10.3 Options</h3> <p><code>idn</code> recognizes these commands: <pre class="verbatim"> -h, --help Print help and exit -V, --version Print version and exit -s, --stringprep Prepare string according to nameprep profile -d, --punycode-decode Decode Punycode -e, --punycode-encode Encode Punycode -a, --idna-to-ascii Convert to ACE according to IDNA (default) -u, --idna-to-unicode Convert from ACE according to IDNA --allow-unassigned Toggle IDNA AllowUnassigned flag (default=off) --usestd3asciirules Toggle IDNA UseSTD3ASCIIRules flag (default=off) -t, --tld Check string for TLD specific rules Only for --idna-to-ascii and --idna-to-unicode (default=on) -p, --profile=STRING Use specified stringprep profile instead Valid stringprep profiles are `Nameprep', `iSCSI', `Nodeprep', `Resourceprep', `trace', and `SASLprep'. --debug Print debugging information (default=off) --quiet Silent operation (default=off) </pre> <h3 class="section">10.4 Environment Variables</h3> <p>The <var>CHARSET</var> environment variable can be used to override what character set to be used for decoding incoming data (i.e., on the command line or on the standard input stream), and to encode data to the standard output. If your system is set up correctly, however, the application will guess which character set is used automatically. Example usage: <pre class="example"> $ CHARSET=ISO-8859-1 idn --punycode-encode ... </pre> <h3 class="section">10.5 Examples</h3> <p>Standard usage, reading input from standard input: <pre class="example"> jas@latte:~$ idn libidn 0.3.5 Copyright 2002, 2003 Simon Josefsson. GNU Libidn comes with NO WARRANTY, to the extent permitted by law. You may redistribute copies of GNU Libidn under the terms of the GNU Lesser General Public License. For more information about these matters, see the file named COPYING.LIB. Type each input string on a line by itself, terminated by a newline character. räksmörgås.se xn--rksmrgs-5wao1o.se jas@latte:~$ </pre> <p>Reading input from command line, and disabling copyright and license information: <pre class="example"> jas@latte:~$ idn --quiet räksmörgås.se blåbærgrød.no xn--rksmrgs-5wao1o.se xn--blbrgrd-fxak7p.no jas@latte:~$ </pre> <p>Accessing a specific StringPrep profile directly: <pre class="example"> jas@latte:~$ idn --quiet --profile=SASLprep --stringprep teßtª teßta jas@latte:~$ </pre> <h3 class="section">10.6 Troubleshooting</h3> <p>Getting character data encoded right, and making sure Libidn use the same encoding, can be difficult. The reason for this is that most systems encode character data in more than one character encoding, i.e., using <code>UTF-8</code> together with <code>ISO-8859-1</code> or <code>ISO-2022-JP</code>. This problem is likely to continue to exist until only one character encoding come out as the evolutionary winner, or (more likely, at least to some extents) forever. <p>The first step to troubleshooting character encoding problems with Libidn is to use the `<samp><span class="samp">--debug</span></samp>' parameter to find out which character set encoding `<samp><span class="samp">idn</span></samp>' believe your locale uses. <pre class="example"> jas@latte:~$ idn --debug --quiet "" system locale uses charset `UTF-8'. jas@latte:~$ </pre> <p>If it prints <code>ANSI_X3.4-1968</code> (i.e., <code>US-ASCII</code>), this indicate you have not configured your locale properly. To configure the locale, you can, for example, use `<samp><span class="samp">LANG=sv_SE.UTF-8; export LANG</span></samp>' at a <code>/bin/sh</code> prompt, to set up your locale for a Swedish environment using <code>UTF-8</code> as the encoding. <p>Sometimes `<samp><span class="samp">idn</span></samp>' appear to be unable to translate from your system locale into <code>UTF-8</code> (which is used internally), and you get an error like the following: <pre class="example"> jas@latte:~$ idn --quiet foo idn: could not convert from ISO-8859-1 to UTF-8. jas@latte:~$ </pre> <p>The simplest explanation is that you haven't installed the `<samp><span class="samp">iconv</span></samp>' conversion tools. You can find it as a standalone library in <acronym>GNU</acronym> Libiconv (<a href="http://www.gnu.org/software/libiconv/">http://www.gnu.org/software/libiconv/</a>). On many <acronym>GNU</acronym>/Linux systems, this library is part of the system, but you may have to install additional packages (e.g., `<samp><span class="samp">glibc-locale</span></samp>' for Debian) to be able to use it. <p>Another explanation is that the error is correct and you are feeding `<samp><span class="samp">idn</span></samp>' invalid data. This can happen inadvertently if you are not careful with the character set encodings you use. For example, if your shell run in a <code>ISO-8859-1</code> environment, and you invoke `<samp><span class="samp">idn</span></samp>' with the `<samp><span class="samp">CHARSET</span></samp>' environment variable as follows, you will feed it <code>ISO-8859-1</code> characters but force it to believe they are <code>UTF-8</code>. Naturally this will lead to an error, unless the byte sequences happen to be parsable as <code>UTF-8</code>. Note that even if you don't get an error, the output may be incorrect in this situation, because <code>ISO-8859-1</code> and <code>UTF-8</code> does not in general encode the same characters as the same byte sequences. <pre class="example"> jas@latte:~$ idn --quiet --debug "" system locale uses charset `ISO-8859-1'. jas@latte:~$ CHARSET=UTF-8 idn --quiet --debug räksmörgås system locale uses charset `UTF-8'. input[0] = U+0072 input[1] = U+4af3 input[2] = U+006d input[3] = U+1b29e5 input[4] = U+0073 output[0] = U+0078 output[1] = U+006e output[2] = U+002d output[3] = U+002d output[4] = U+0072 output[5] = U+006d output[6] = U+0073 output[7] = U+002d output[8] = U+0068 output[9] = U+0069 output[10] = U+0036 output[11] = U+0064 output[12] = U+0035 output[13] = U+0039 output[14] = U+0037 output[15] = U+0035 output[16] = U+0035 output[17] = U+0032 output[18] = U+0061 xn--rms-hi6d597552a jas@latte:~$ </pre> <p>The sense moral here is to forget about `<samp><span class="samp">CHARSET</span></samp>' (configure your locales properly instead) unless you know what you are doing, and if you want to use it, do it carefully, after verifying with `<samp><span class="samp">--debug</span></samp>' that you get the desired results. <div class="node"> <p><hr> <a name="Emacs-API"></a> Next: <a rel="next" accesskey="n" href="#Java-API">Java API</a>, Previous: <a rel="previous" accesskey="p" href="#Invoking-idn">Invoking idn</a>, Up: <a rel="up" accesskey="u" href="#Top">Top</a> </div> <h2 class="chapter">11 Emacs API</h2> <p>Included in Libidn are <samp><span class="file">punycode.el</span></samp> and <samp><span class="file">idna.el</span></samp> that provides an Emacs Lisp API to (a limited set of) the Libidn API. This section describes the API. Currently the IDNA API always set the <code>UseSTD3ASCIIRules</code> flag and clear the <code>AllowUnassigned</code> flag, in the future there may be functionality to specify these flags via the API. <h3 class="section">11.1 Punycode Emacs API</h3> <div class="defun"> — Variable: <b>punycode-program</b><var><a name="index-punycode_002dprogram-109"></a></var><br> <blockquote><p>Name of the GNU Libidn <samp><span class="file">idn</span></samp> application. The default is `<samp><span class="samp">idn</span></samp>'. This variable can be customized. </p></blockquote></div> <div class="defun"> — Variable: <b>punycode-environment</b><var><a name="index-punycode_002denvironment-110"></a></var><br> <blockquote><p>List of environment variable definitions prepended to `<samp><span class="samp">process-environment</span></samp>'. The default is `<samp><span class="samp">("CHARSET=UTF-8")</span></samp>'. This variable can be customized. </p></blockquote></div> <div class="defun"> — Variable: <b>punycode-encode-parameters</b><var><a name="index-punycode_002dencode_002dparameters-111"></a></var><br> <blockquote><p>List of parameters passed to <var>punycode-program</var> to invoke punycode encoding mode. The default is `<samp><span class="samp">("--quiet" "--punycode-encode")</span></samp>'. This variable can be customized. </p></blockquote></div> <div class="defun"> — Variable: <b>punycode-decode-parameters</b><var><a name="index-punycode_002ddecode_002dparameters-112"></a></var><br> <blockquote><p>Parameters passed to <var>punycode-program</var> to invoke punycode decoding mode. The default is `<samp><span class="samp">("--quiet" "--punycode-decode")</span></samp>'. This variable can be customized. </p></blockquote></div> <div class="defun"> — Function: <b>punycode-encode</b><var> string<a name="index-punycode_002dencode-113"></a></var><br> <blockquote><p>Returns a Punycode encoding of the <var>string</var>, after converting the input into UTF-8. </p></blockquote></div> <div class="defun"> — Function: <b>punycode-decode</b><var> string<a name="index-punycode_002ddecode-114"></a></var><br> <blockquote><p>Returns a possibly multibyte string which is the decoding of the <var>string</var> which is a punycode encoded string. </p></blockquote></div> <h3 class="section">11.2 IDNA Emacs API</h3> <div class="defun"> — Variable: <b>idna-program</b><var><a name="index-idna_002dprogram-115"></a></var><br> <blockquote><p>Name of the GNU Libidn <samp><span class="file">idn</span></samp> application. The default is `<samp><span class="samp">idn</span></samp>'. This variable can be customized. </p></blockquote></div> <div class="defun"> — Variable: <b>idna-environment</b><var><a name="index-idna_002denvironment-116"></a></var><br> <blockquote><p>List of environment variable definitions prepended to `<samp><span class="samp">process-environment</span></samp>'. The default is `<samp><span class="samp">("CHARSET=UTF-8")</span></samp>'. This variable can be customized. </p></blockquote></div> <div class="defun"> — Variable: <b>idna-to-ascii-parameters</b><var><a name="index-idna_002dto_002dascii_002dparameters-117"></a></var><br> <blockquote><p>List of parameters passed to <var>idna-program</var> to invoke IDNA ToASCII mode. The default is `<samp><span class="samp">("--quiet" "--idna-to-ascii" "--usestd3asciirules")</span></samp>'. This variable can be customized. </p></blockquote></div> <div class="defun"> — Variable: <b>idna-to-unicode-parameters</b><var><a name="index-idna_002dto_002dunicode_002dparameters-118"></a></var><br> <blockquote><p>Parameters passed <var>idna-program</var> to invoke IDNA ToUnicode mode. The default is `<samp><span class="samp">("--quiet" "--idna-to-unicode" "--usestd3asciirules")</span></samp>'. This variable can be customized. </p></blockquote></div> <div class="defun"> — Function: <b>idna-to-ascii</b><var> string<a name="index-idna_002dto_002dascii-119"></a></var><br> <blockquote><p>Returns an ASCII Compatible Encoding (ACE) of the string computed by the IDNA ToASCII operation on the input <var>string</var>, after converting the input to UTF-8. </p></blockquote></div> <div class="defun"> — Function: <b>idna-to-unicode</b><var> string<a name="index-idna_002dto_002dunicode-120"></a></var><br> <blockquote><p>Returns a possibly multibyte string which is the output of the IDNA ToUnicode operation computed on the input <var>string</var>. </p></blockquote></div> <div class="node"> <p><hr> <a name="Java-API"></a> Next: <a rel="next" accesskey="n" href="#C_0023-API">C# API</a>, Previous: <a rel="previous" accesskey="p" href="#Emacs-API">Emacs API</a>, Up: <a rel="up" accesskey="u" href="#Top">Top</a> </div> <h2 class="chapter">12 Java API</h2> <p>Libidn has been ported to the Java programming language, and as a consequence most of the API is available to native Java applications. This section contain notes on this support, complete documentation is pending. <p>The Java library, if Libidn has been built with Java support (see <a href="#Downloading-and-Installing">Downloading and Installing</a>), will be placed in <samp><span class="file">java/libidn.jar</span></samp>. The source code is located in <samp><span class="file">java/gnu/inet/encoding/</span></samp>. <h3 class="section">12.1 Overview</h3> <p>This package provides a Java implementation of the Internationalized Domain Names in Applications (IDNA) standard. It is written entirely in Java and does not require any additional libraries to be set up. <p>The gnu.inet.encoding.IDNA class offers two public functions, toASCII and toUnicode which can be used as follows: <pre class="example"> gnu.inet.encoding.IDNA.toASCII("blöds.züg"); gnu.inet.encoding.IDNA.toUnicode("xn--blds-6qa.xn--zg-xka"); </pre> <h3 class="section">12.2 Miscellaneous Programs</h3> <p>The <samp><span class="file">misc/</span></samp> directory contains several programs that are related to the Java part of GNU Libidn, but that don't need to be included in the main source tree. <h4 class="subsection">12.2.1 GenerateRFC3454</h4> <p>This program parses RFC3454 and creates the RFC3454.java program that is required during the StringPrep phase. <p>The RFC can be found at various locations, for example at <a href="http://www.ietf.org/rfc/rfc3454.txt">http://www.ietf.org/rfc/rfc3454.txt</a>. <p>Invoke the program as follows: <pre class="example"> $ java GenerateRFC3454 Creating RFC3454.java... Ok. </pre> <h4 class="subsection">12.2.2 GenerateNFKC</h4> <p>The GenerateNFKC program parses the Unicode character database file and generates all the tables required for NFKC. This program requires the two files UnicodeData.txt and CompositionExclusions.txt of version 3.2 of the Unicode files. Note that RFC3454 (Stringprep) defines that Unicode version 3.2 is to be used, not the latest version. <p>The Unicode data files can be found at <a href="http://www.unicode.org/Public/">http://www.unicode.org/Public/</a>. <p>Invoke the program as follows: <pre class="example"> $ java GenerateNFKC Creating CombiningClass.java... Ok. Creating DecompositionKeys.java... Ok. Creating DecompositionMappings.java... Ok. Creating Composition.java... Ok. </pre> <h4 class="subsection">12.2.3 TestIDNA</h4> <p>The TestIDNA program allows to test the IDNA implementation manually or against Simon Josefsson's test vectors. <p>The test vectors can be found at the Libidn homepage, <a href="http://www.gnu.org/software/libidn/">http://www.gnu.org/software/libidn/</a>. <p>To test the tranformation manually, use: <pre class="example"> $ java -cp .:../libidn.jar TestIDNA -a <string to test> Input: <string to test> Output: <toASCII(string to test)> $ java -cp .:../libidn.jar TestIDNA -u <string to test> Input: <string to test> Output: <toUnicode(string to test)> </pre> <p>To test against draft-josefsson-idn-test-vectors.html, use: <pre class="example"> $ java -cp .:../libidn.jar TestIDNA -t No errors detected! </pre> <h4 class="subsection">12.2.4 TestNFKC</h4> <p>The TestNFKC program allows to test the NFKC implementation manually or against the NormalizationTest.txt file from the Unicode data files. <p>To test the normalization manually, use: <pre class="example"> $ java -cp .:../libidn.jar TestNFKC <string to test> Input: <string to test> Output: <nfkc version of the string to test> </pre> <p>To test against NormalizationTest.txt: <pre class="example"> $ java -cp .:../libidn.jar TestNFKC No errors detected! </pre> <h3 class="section">12.3 Possible Problems</h3> <p>Beware of Bugs: This Java API needs a lot more testing, especially with "exotic" character sets. While it works for me, it may not work for you. <p>Encoding of your Java sources: If you are using non-ASCII characters in your Java source code, make sure javac compiles your programs with the correct encoding. If necessary specify the encoding using the -encoding parameter. <p>Java Unicode handling: Java 1.4 only handles 16-bit Unicode code points (i.e. characters in the Basic Multilingual Plane), this implementation therefore ignores all references to so-called Supplementary Characters (U+10000 to U+10FFFF). Starting from Java 1.5, these characters will also be supported by Java, but this will require changes to this library. See also the next section. <h3 class="section">12.4 A Note on Java and Unicode</h3> <p>This library uses Java's builtin 'char' datatype. Up to Java 1.4, this datatype only supports 16-bit Unicode code points, also called the Basic Multilingual Plane. For this reason, this library doesn't work for Supplementary Characters (i.e. characters from U+10000 to U+10FFFF). All references to such characters are silently ignored. <p>Starting from Java 1.5, also Supplementary Characters will be supported. However, this will require changes in the present version of the library. Java 1.5 is currently in beta status. <p>For more information refer to the documentation of java.lang.Character in the JDK API. <div class="node"> <p><hr> <a name="C%23-API"></a> <a name="C_0023-API"></a> Next: <a rel="next" accesskey="n" href="#Acknowledgements">Acknowledgements</a>, Previous: <a rel="previous" accesskey="p" href="#Java-API">Java API</a>, Up: <a rel="up" accesskey="u" href="#Top">Top</a> </div> <h2 class="chapter">13 C# API</h2> <p>The Libidn library has been ported to the C# language. The port reside in the top-level <samp><span class="file">csharp/</span></samp> directory. Currently, no further documentation about the implementation or the API is available. However, the C# port was based on the Java port, and the API is exactly the same as in the Java version. The help files for the Java API may thus be useful. <!-- ********************************************************** --> <!-- ******************* Acknowledgements ******************* --> <!-- ********************************************************** --> <div class="node"> <p><hr> <a name="Acknowledgements"></a> Next: <a rel="next" accesskey="n" href="#History">History</a>, Previous: <a rel="previous" accesskey="p" href="#C_0023-API">C# API</a>, Up: <a rel="up" accesskey="u" href="#Top">Top</a> </div> <h2 class="chapter">14 Acknowledgements</h2> <p>The punycode implementation was taken from the IETF IDN Punycode specification, by Adam M. Costello. The TLD code was contributed by Thomas Jacob. The Java implementation was contributed by Oliver Hitz. The C# implementation was contributed by Alexander Gnauck. The Unicode tables were provided by Unicode, Inc. Some functions for dealing with Unicode (see nfkc.c and toutf8.c) were borrowed from GLib, downloaded from <a href="http://www.gtk.org/">http://www.gtk.org/</a>. The manual borrowed text from Libgcrypt by Werner Koch. <p>Inspiration for many things that, consciously or not, have gone into this package is due to a number of free software package that the author has been exposed to. The author wishes to acknowledge the free software community in general, for giving an example on what role software development can play in the modern society. <p>Several people reported bugs, sent patches or suggested improvements, see the file THANKS in the top-level directory of the source code. <!-- ********************************************************** --> <!-- ************************ History *********************** --> <!-- ********************************************************** --> <div class="node"> <p><hr> <a name="History"></a> Next: <a rel="next" accesskey="n" href="#PR29-discussion">PR29 discussion</a>, Previous: <a rel="previous" accesskey="p" href="#Acknowledgements">Acknowledgements</a>, Up: <a rel="up" accesskey="u" href="#Top">Top</a> </div> <h2 class="chapter">15 History</h2> <p>The complete history of user visible changes is stored in the file <samp><span class="file">NEWS</span></samp> in the top-level directory of the source code tree. The complete history of modifications to each file is stored in the file <samp><span class="file">ChangeLog</span></samp> in the same directory. This section contain a condensed version of that information, in the form of “milestones” for the project. <dl> <dt>Stringprep implementation.<dd>Version 0.0.0 released on 2002-11-05. <br><dt>IDNA and Punycode implementations, part of the GNU project.<dd>Version 0.1.0 released on 2003-01-05. <br><dt>Uses official IDNA ACE prefix 'xn–'.<dd>Version 0.1.7 released on 2003-02-12. <br><dt>Command line interface.<dd>Version 0.1.11 released on 2003-02-26. <br><dt>GNU Libc add-on proposed.<dd>Version 0.1.12 released on 2003-03-06. <br><dt>Interoperability testing during IDNConnect.<dd>Version 0.3.1 released on 2003-10-02. <br><dt>TLD restriction testing.<dd>Version 0.4.0 released on 2004-02-28. <br><dt>GNU Libc add-on integrated.<dd>Version 0.4.1 released on 2004-03-08. <br><dt>Native Java implementation.<dd>Version 0.4.2-0.4.9 released between 2004-03-20 and 2004-06-11. <br><dt>PR-29 functions for “problem sequences”.<dd>Version 0.5.0 released on 2004-06-26. <br><dt>Many small portability fixes and wider use.<dd>Version 0.5.1 through 0.5.20, released between 2004-07-09 and 2005-10-23. <br><dt>Native C# implementation.<dd>Version 0.6.0 released on 2005-12-03. <br><dt>Windows support through cross-compilation.<dd>Version 0.6.1 released on 2006-01-20. </dl> <div class="node"> <p><hr> <a name="PR29-discussion"></a> Next: <a rel="next" accesskey="n" href="#Copying-Information">Copying Information</a>, Previous: <a rel="previous" accesskey="p" href="#History">History</a>, Up: <a rel="up" accesskey="u" href="#Top">Top</a> </div> <h2 class="appendix">Appendix A PR29 discussion</h2> <p>If you wish to experiment with a modified Unicode NFKC implementation according to the PR29 proposal, you may find the following bug report useful. However, I have not verified that the suggested modifications are correct. For reference, I'm including my response to the report as well. <pre class="verbatim"> From: Rick McGowan <rick@unicode.org> Subject: Possible bug and status of PR 29 change(s) To: bug-libidn@gnu.org Date: Wed, 27 Oct 2004 14:49:17 -0700 Hello. On behalf of the Unicode Consortium editorial committee, I would like to find out more information about the PR 29 fixes, if any, and functions in Libidn. Your implementation was listed in the text of PR29 as needing investigation, so I am following up on several implementations. The UTC has accepted the proposed fix to D2 as outlined in PR29, and a new draft of UAX #15 has been issued. I have looked at Libidn 0.5.8 (today), and there may still be a possible bug in NFKC.java and nfkc.c. ------------------------------------------------------ 1. In NFKC.java, this line in canonicalOrdering(): if (i > 0 && (last_cc == 0 || last_cc != cc)) { should perhaps be changed to: if (i > 0 && (last_cc == 0 || last_cc < cc)) { but I'm not sure of the sense of this comparison. ------------------------------------------------------ 2. In nfkc.c, function _g_utf8_normalize_wc() has this code: if (i > 0 && (last_cc == 0 || last_cc != cc) && combine (wc_buffer[last_start], wc_buffer[i], &wc_buffer[last_start])) { This appears to have the same bug as the current Python implementation (in Python 2.3.4). The code should be checking, as per new rule D2 UAX #15 update, that the next combining character is the same or HIGHER than the current one. It now checks to see if it's non-zero and not equal. The above line(s) should perhaps be changed to: if (i > 0 && (last_cc == 0 || last_cc < cc) && combine (wc_buffer[last_start], wc_buffer[i], &wc_buffer[last_start])) { but I'm not sure of the sense of the comparison (< or > or <=?) here. In the text of PR29, I will be marking Libidn as "needs change" and adding the version number that I checked. If any further change is made, please let me know the release version, and I'll update again. Regards, Rick McGowan </pre> <pre class="verbatim"> From: Simon Josefsson <jas@extundo.com> Subject: Re: Possible bug and status of PR 29 change(s) To: Rick McGowan <rick@unicode.org> Cc: bug-libidn@gnu.org Date: Thu, 28 Oct 2004 09:47:47 +0200 Rick McGowan <rick@unicode.org> writes: > Hello. On behalf of the Unicode Consortium editorial committee, I would > like to find out more information about the PR 29 fixes, if any, and > functions in Libidn. Your implementation was listed in the text of PR29 as > needing investigation, so I am following up on several implementations. > > The UTC has accepted the proposed fix to D2 as outlined in PR29, and a new > draft of UAX #15 has been issued. > > I have looked at Libidn 0.5.8 (today), and there may still be a possible > bug in NFKC.java and nfkc.c. Hello Rick. I believe the current behavior is intentional. Libidn do not aim to implement latest-and-greatest NFKC, it aim to implement the NFKC functionality required for StringPrep and IDN. As you may know, StringPrep/IDN reference Unicode 3.2.0, and explicitly says any later changes (which I consider PR29 as) do not apply. In fact, I believe that would I incorporate the changes suggested in PR29, I would in fact be violating the IDN specifications. Thanks for looking into the code and finding the place where the change could be made. I'll see if I can mention this in the manual somewhere, for technically interested readers. Regards, Simon </pre> <div class="node"> <p><hr> <a name="Copying-Information"></a> Next: <a rel="next" accesskey="n" href="#Function-and-Variable-Index">Function and Variable Index</a>, Previous: <a rel="previous" accesskey="p" href="#PR29-discussion">PR29 discussion</a>, Up: <a rel="up" accesskey="u" href="#Top">Top</a> </div> <h2 class="appendix">Appendix B Copying Information</h2> <ul class="menu"> <li><a accesskey="1" href="#GNU-Free-Documentation-License">GNU Free Documentation License</a>: License for copying this manual. <li><a accesskey="2" href="#GNU-LGPL">GNU LGPL</a>: License for copying the library. <li><a accesskey="3" href="#GNU-GPL">GNU GPL</a>: License for copying the programs. </ul> <div class="node"> <p><hr> <a name="GNU-Free-Documentation-License"></a> Next: <a rel="next" accesskey="n" href="#GNU-LGPL">GNU LGPL</a>, Up: <a rel="up" accesskey="u" href="#Copying-Information">Copying Information</a> </div> <h3 class="appendixsec">B.1 GNU Free Documentation License</h3> <p><a name="index-FDL_002c-GNU-Free-Documentation-License-121"></a><div align="center">Version 1.2, November 2002</div> <pre class="display"> Copyright © 2000,2001,2002 Free Software Foundation, Inc. 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA Everyone is permitted to copy and distribute verbatim copies of this license document, but changing it is not allowed. </pre> <ol type=1 start=0> <li>PREAMBLE <p>The purpose of this License is to make a manual, textbook, or other functional and useful document <dfn>free</dfn> in the sense of freedom: to assure everyone the effective freedom to copy and redistribute it, with or without modifying it, either commercially or noncommercially. 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If the Document does not specify a version number of this License, you may choose any version ever published (not as a draft) by the Free Software Foundation. </ol> <h3 class="heading">ADDENDUM: How to use this License for your documents</h3> <p>To use this License in a document you have written, include a copy of the License in the document and put the following copyright and license notices just after the title page: <pre class="smallexample"> Copyright (C) <var>year</var> <var>your name</var>. Permission is granted to copy, distribute and/or modify this document under the terms of the GNU Free Documentation License, Version 1.2 or any later version published by the Free Software Foundation; with no Invariant Sections, no Front-Cover Texts, and no Back-Cover Texts. A copy of the license is included in the section entitled ``GNU Free Documentation License''. </pre> <p>If you have Invariant Sections, Front-Cover Texts and Back-Cover Texts, replace the “with...Texts.” line with this: <pre class="smallexample"> with the Invariant Sections being <var>list their titles</var>, with the Front-Cover Texts being <var>list</var>, and with the Back-Cover Texts being <var>list</var>. </pre> <p>If you have Invariant Sections without Cover Texts, or some other combination of the three, merge those two alternatives to suit the situation. <p>If your document contains nontrivial examples of program code, we recommend releasing these examples in parallel under your choice of free software license, such as the GNU General Public License, to permit their use in free software. <!-- Local Variables: --> <!-- ispell-local-pdict: "ispell-dict" --> <!-- End: --> <div class="node"> <p><hr> <a name="GNU-LGPL"></a> Next: <a rel="next" accesskey="n" href="#GNU-GPL">GNU GPL</a>, Previous: <a rel="previous" accesskey="p" href="#GNU-Free-Documentation-License">GNU Free Documentation License</a>, Up: <a rel="up" accesskey="u" href="#Copying-Information">Copying Information</a> </div> <h3 class="appendixsec">B.2 GNU Lesser General Public License</h3> <p><a name="index-LGPL_002c-GNU-Lesser-General-Public-License-122"></a><a name="index-License_002c-GNU-LGPL-123"></a><div align="center">Version 2.1, February 1999</div> <pre class="display"> Copyright © 1991, 1999 Free Software Foundation, Inc. 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA Everyone is permitted to copy and distribute verbatim copies of this license document, but changing it is not allowed. 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You can do so by permitting redistribution under these terms (or, alternatively, under the terms of the ordinary General Public License). <p>To apply these terms, attach the following notices to the library. It is safest to attach them to the start of each source file to most effectively convey the exclusion of warranty; and each file should have at least the “copyright” line and a pointer to where the full notice is found. <pre class="smallexample"> <var>one line to give the library's name and an idea of what it does.</var> Copyright (C) <var>year</var> <var>name of author</var> This library is free software; you can redistribute it and/or modify it under the terms of the GNU Lesser General Public License as published by the Free Software Foundation; either version 2.1 of the License, or (at your option) any later version. This library is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more details. You should have received a copy of the GNU Lesser General Public License along with this library; if not, write to the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. </pre> <p>Also add information on how to contact you by electronic and paper mail. <p>You should also get your employer (if you work as a programmer) or your school, if any, to sign a “copyright disclaimer” for the library, if necessary. Here is a sample; alter the names: <pre class="smallexample"> Yoyodyne, Inc., hereby disclaims all copyright interest in the library `Frob' (a library for tweaking knobs) written by James Random Hacker. <var>signature of Ty Coon</var>, 1 April 1990 Ty Coon, President of Vice </pre> <p>That's all there is to it! <div class="node"> <p><hr> <a name="GNU-GPL"></a> Previous: <a rel="previous" accesskey="p" href="#GNU-LGPL">GNU LGPL</a>, Up: <a rel="up" accesskey="u" href="#Copying-Information">Copying Information</a> </div> <h3 class="appendixsec">B.3 GNU General Public License</h3> <p><a name="index-GPL_002c-GNU-General-Public-License-124"></a><a name="index-License_002c-GNU-GPL-125"></a><div align="center">Version 2, June 1991</div> <!-- This file is intended to be included in another file. --> <pre class="display"> Copyright © 1989, 1991 Free Software Foundation, Inc. 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA Everyone is permitted to copy and distribute verbatim copies of this license document, but changing it is not allowed. </pre> <h3 class="heading">Preamble</h3> <p>The licenses for most software are designed to take away your freedom to share and change it. By contrast, the GNU General Public License is intended to guarantee your freedom to share and change free software—to make sure the software is free for all its users. This General Public License applies to most of the Free Software Foundation's software and to any other program whose authors commit to using it. (Some other Free Software Foundation software is covered by the GNU Lesser General Public License instead.) You can apply it to your programs, too. <p>When we speak of free software, we are referring to freedom, not price. Our General Public Licenses are designed to make sure that you have the freedom to distribute copies of free software (and charge for this service if you wish), that you receive source code or can get it if you want it, that you can change the software or use pieces of it in new free programs; and that you know you can do these things. <p>To protect your rights, we need to make restrictions that forbid anyone to deny you these rights or to ask you to surrender the rights. These restrictions translate to certain responsibilities for you if you distribute copies of the software, or if you modify it. <p>For example, if you distribute copies of such a program, whether gratis or for a fee, you must give the recipients all the rights that you have. You must make sure that they, too, receive or can get the source code. And you must show them these terms so they know their rights. <p>We protect your rights with two steps: (1) copyright the software, and (2) offer you this license which gives you legal permission to copy, distribute and/or modify the software. <p>Also, for each author's protection and ours, we want to make certain that everyone understands that there is no warranty for this free software. If the software is modified by someone else and passed on, we want its recipients to know that what they have is not the original, so that any problems introduced by others will not reflect on the original authors' reputations. <p>Finally, any free program is threatened constantly by software patents. We wish to avoid the danger that redistributors of a free program will individually obtain patent licenses, in effect making the program proprietary. To prevent this, we have made it clear that any patent must be licensed for everyone's free use or not licensed at all. <p>The precise terms and conditions for copying, distribution and modification follow. <h3 class="heading">TERMS AND CONDITIONS FOR COPYING, DISTRIBUTION AND MODIFICATION</h3> <ol type=1 start=0> <li>This License applies to any program or other work which contains a notice placed by the copyright holder saying it may be distributed under the terms of this General Public License. The “Program”, below, refers to any such program or work, and a “work based on the Program” means either the Program or any derivative work under copyright law: that is to say, a work containing the Program or a portion of it, either verbatim or with modifications and/or translated into another language. (Hereinafter, translation is included without limitation in the term “modification”.) Each licensee is addressed as “you”. <p>Activities other than copying, distribution and modification are not covered by this License; they are outside its scope. The act of running the Program is not restricted, and the output from the Program is covered only if its contents constitute a work based on the Program (independent of having been made by running the Program). Whether that is true depends on what the Program does. <li>You may copy and distribute verbatim copies of the Program's source code as you receive it, in any medium, provided that you conspicuously and appropriately publish on each copy an appropriate copyright notice and disclaimer of warranty; keep intact all the notices that refer to this License and to the absence of any warranty; and give any other recipients of the Program a copy of this License along with the Program. <p>You may charge a fee for the physical act of transferring a copy, and you may at your option offer warranty protection in exchange for a fee. <li>You may modify your copy or copies of the Program or any portion of it, thus forming a work based on the Program, and copy and distribute such modifications or work under the terms of Section 1 above, provided that you also meet all of these conditions: <ol type=a start=1> <li>You must cause the modified files to carry prominent notices stating that you changed the files and the date of any change. <li>You must cause any work that you distribute or publish, that in whole or in part contains or is derived from the Program or any part thereof, to be licensed as a whole at no charge to all third parties under the terms of this License. <li>If the modified program normally reads commands interactively when run, you must cause it, when started running for such interactive use in the most ordinary way, to print or display an announcement including an appropriate copyright notice and a notice that there is no warranty (or else, saying that you provide a warranty) and that users may redistribute the program under these conditions, and telling the user how to view a copy of this License. (Exception: if the Program itself is interactive but does not normally print such an announcement, your work based on the Program is not required to print an announcement.) </ol> <p>These requirements apply to the modified work as a whole. If identifiable sections of that work are not derived from the Program, and can be reasonably considered independent and separate works in themselves, then this License, and its terms, do not apply to those sections when you distribute them as separate works. But when you distribute the same sections as part of a whole which is a work based on the Program, the distribution of the whole must be on the terms of this License, whose permissions for other licensees extend to the entire whole, and thus to each and every part regardless of who wrote it. <p>Thus, it is not the intent of this section to claim rights or contest your rights to work written entirely by you; rather, the intent is to exercise the right to control the distribution of derivative or collective works based on the Program. <p>In addition, mere aggregation of another work not based on the Program with the Program (or with a work based on the Program) on a volume of a storage or distribution medium does not bring the other work under the scope of this License. <li>You may copy and distribute the Program (or a work based on it, under Section 2) in object code or executable form under the terms of Sections 1 and 2 above provided that you also do one of the following: <ol type=a start=1> <li>Accompany it with the complete corresponding machine-readable source code, which must be distributed under the terms of Sections 1 and 2 above on a medium customarily used for software interchange; or, <li>Accompany it with a written offer, valid for at least three years, to give any third party, for a charge no more than your cost of physically performing source distribution, a complete machine-readable copy of the corresponding source code, to be distributed under the terms of Sections 1 and 2 above on a medium customarily used for software interchange; or, <li>Accompany it with the information you received as to the offer to distribute corresponding source code. (This alternative is allowed only for noncommercial distribution and only if you received the program in object code or executable form with such an offer, in accord with Subsection b above.) </ol> <p>The source code for a work means the preferred form of the work for making modifications to it. For an executable work, complete source code means all the source code for all modules it contains, plus any associated interface definition files, plus the scripts used to control compilation and installation of the executable. However, as a special exception, the source code distributed need not include anything that is normally distributed (in either source or binary form) with the major components (compiler, kernel, and so on) of the operating system on which the executable runs, unless that component itself accompanies the executable. <p>If distribution of executable or object code is made by offering access to copy from a designated place, then offering equivalent access to copy the source code from the same place counts as distribution of the source code, even though third parties are not compelled to copy the source along with the object code. <li>You may not copy, modify, sublicense, or distribute the Program except as expressly provided under this License. Any attempt otherwise to copy, modify, sublicense or distribute the Program is void, and will automatically terminate your rights under this License. However, parties who have received copies, or rights, from you under this License will not have their licenses terminated so long as such parties remain in full compliance. <li>You are not required to accept this License, since you have not signed it. However, nothing else grants you permission to modify or distribute the Program or its derivative works. These actions are prohibited by law if you do not accept this License. Therefore, by modifying or distributing the Program (or any work based on the Program), you indicate your acceptance of this License to do so, and all its terms and conditions for copying, distributing or modifying the Program or works based on it. <li>Each time you redistribute the Program (or any work based on the Program), the recipient automatically receives a license from the original licensor to copy, distribute or modify the Program subject to these terms and conditions. You may not impose any further restrictions on the recipients' exercise of the rights granted herein. You are not responsible for enforcing compliance by third parties to this License. <li>If, as a consequence of a court judgment or allegation of patent infringement or for any other reason (not limited to patent issues), conditions are imposed on you (whether by court order, agreement or otherwise) that contradict the conditions of this License, they do not excuse you from the conditions of this License. If you cannot distribute so as to satisfy simultaneously your obligations under this License and any other pertinent obligations, then as a consequence you may not distribute the Program at all. For example, if a patent license would not permit royalty-free redistribution of the Program by all those who receive copies directly or indirectly through you, then the only way you could satisfy both it and this License would be to refrain entirely from distribution of the Program. <p>If any portion of this section is held invalid or unenforceable under any particular circumstance, the balance of the section is intended to apply and the section as a whole is intended to apply in other circumstances. <p>It is not the purpose of this section to induce you to infringe any patents or other property right claims or to contest validity of any such claims; this section has the sole purpose of protecting the integrity of the free software distribution system, which is implemented by public license practices. Many people have made generous contributions to the wide range of software distributed through that system in reliance on consistent application of that system; it is up to the author/donor to decide if he or she is willing to distribute software through any other system and a licensee cannot impose that choice. <p>This section is intended to make thoroughly clear what is believed to be a consequence of the rest of this License. <li>If the distribution and/or use of the Program is restricted in certain countries either by patents or by copyrighted interfaces, the original copyright holder who places the Program under this License may add an explicit geographical distribution limitation excluding those countries, so that distribution is permitted only in or among countries not thus excluded. In such case, this License incorporates the limitation as if written in the body of this License. <li>The Free Software Foundation may publish revised and/or new versions of the General Public License from time to time. Such new versions will be similar in spirit to the present version, but may differ in detail to address new problems or concerns. <p>Each version is given a distinguishing version number. If the Program specifies a version number of this License which applies to it and “any later version”, you have the option of following the terms and conditions either of that version or of any later version published by the Free Software Foundation. If the Program does not specify a version number of this License, you may choose any version ever published by the Free Software Foundation. <li>If you wish to incorporate parts of the Program into other free programs whose distribution conditions are different, write to the author to ask for permission. For software which is copyrighted by the Free Software Foundation, write to the Free Software Foundation; we sometimes make exceptions for this. Our decision will be guided by the two goals of preserving the free status of all derivatives of our free software and of promoting the sharing and reuse of software generally. <li>BECAUSE THE PROGRAM IS LICENSED FREE OF CHARGE, THERE IS NO WARRANTY FOR THE PROGRAM, TO THE EXTENT PERMITTED BY APPLICABLE LAW. EXCEPT WHEN OTHERWISE STATED IN WRITING THE COPYRIGHT HOLDERS AND/OR OTHER PARTIES PROVIDE THE PROGRAM “AS IS” WITHOUT WARRANTY OF ANY KIND, EITHER EXPRESSED OR IMPLIED, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. THE ENTIRE RISK AS TO THE QUALITY AND PERFORMANCE OF THE PROGRAM IS WITH YOU. SHOULD THE PROGRAM PROVE DEFECTIVE, YOU ASSUME THE COST OF ALL NECESSARY SERVICING, REPAIR OR CORRECTION. <li>IN NO EVENT UNLESS REQUIRED BY APPLICABLE LAW OR AGREED TO IN WRITING WILL ANY COPYRIGHT HOLDER, OR ANY OTHER PARTY WHO MAY MODIFY AND/OR REDISTRIBUTE THE PROGRAM AS PERMITTED ABOVE, BE LIABLE TO YOU FOR DAMAGES, INCLUDING ANY GENERAL, SPECIAL, INCIDENTAL OR CONSEQUENTIAL DAMAGES ARISING OUT OF THE USE OR INABILITY TO USE THE PROGRAM (INCLUDING BUT NOT LIMITED TO LOSS OF DATA OR DATA BEING RENDERED INACCURATE OR LOSSES SUSTAINED BY YOU OR THIRD PARTIES OR A FAILURE OF THE PROGRAM TO OPERATE WITH ANY OTHER PROGRAMS), EVEN IF SUCH HOLDER OR OTHER PARTY HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES. </ol> <h3 class="heading">Appendix: How to Apply These Terms to Your New Programs</h3> <p>If you develop a new program, and you want it to be of the greatest possible use to the public, the best way to achieve this is to make it free software which everyone can redistribute and change under these terms. <p>To do so, attach the following notices to the program. It is safest to attach them to the start of each source file to most effectively convey the exclusion of warranty; and each file should have at least the “copyright” line and a pointer to where the full notice is found. <pre class="smallexample"> <var>one line to give the program's name and a brief idea of what it does.</var> Copyright (C) <var>yyyy</var> <var>name of author</var> This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version. This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with this program; if not, write to the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. </pre> <p>Also add information on how to contact you by electronic and paper mail. <p>If the program is interactive, make it output a short notice like this when it starts in an interactive mode: <pre class="smallexample"> Gnomovision version 69, Copyright (C) <var>year</var> <var>name of author</var> Gnomovision comes with ABSOLUTELY NO WARRANTY; for details type `show w'. This is free software, and you are welcome to redistribute it under certain conditions; type `show c' for details. </pre> <p>The hypothetical commands `<samp><span class="samp">show w</span></samp>' and `<samp><span class="samp">show c</span></samp>' should show the appropriate parts of the General Public License. Of course, the commands you use may be called something other than `<samp><span class="samp">show w</span></samp>' and `<samp><span class="samp">show c</span></samp>'; they could even be mouse-clicks or menu items—whatever suits your program. <p>You should also get your employer (if you work as a programmer) or your school, if any, to sign a “copyright disclaimer” for the program, if necessary. Here is a sample; alter the names: <pre class="example"> Yoyodyne, Inc., hereby disclaims all copyright interest in the program `Gnomovision' (which makes passes at compilers) written by James Hacker. <var>signature of Ty Coon</var>, 1 April 1989 Ty Coon, President of Vice </pre> <p>This General Public License does not permit incorporating your program into proprietary programs. If your program is a subroutine library, you may consider it more useful to permit linking proprietary applications with the library. If this is what you want to do, use the GNU Lesser General Public License instead of this License. <div class="node"> <p><hr> <a name="Function-and-Variable-Index"></a> Next: <a rel="next" accesskey="n" href="#Concept-Index">Concept Index</a>, Previous: <a rel="previous" accesskey="p" href="#Copying-Information">Copying Information</a>, Up: <a rel="up" accesskey="u" href="#Top">Top</a> </div> <h2 class="unnumbered">Function and Variable Index</h2> <ul class="index-fn" compact> <li><a href="#index-idna_002dto_002dascii-119"><code>idna-to-ascii</code></a>: <a href="#Emacs-API">Emacs API</a></li> <li><a href="#index-idna_002dto_002dunicode-120"><code>idna-to-unicode</code></a>: <a href="#Emacs-API">Emacs API</a></li> <li><a href="#index-idna_005fstrerror-86"><code>idna_strerror</code></a>: <a href="#IDNA-Functions">IDNA Functions</a></li> <li><a href="#index-idna_005fto_005fascii_005f4i-76"><code>idna_to_ascii_4i</code></a>: <a href="#IDNA-Functions">IDNA Functions</a></li> <li><a href="#index-idna_005fto_005fascii_005f4z-78"><code>idna_to_ascii_4z</code></a>: <a href="#IDNA-Functions">IDNA Functions</a></li> <li><a href="#index-idna_005fto_005fascii_005f8z-79"><code>idna_to_ascii_8z</code></a>: <a href="#IDNA-Functions">IDNA Functions</a></li> <li><a href="#index-idna_005fto_005fascii_005flz-80"><code>idna_to_ascii_lz</code></a>: <a href="#IDNA-Functions">IDNA Functions</a></li> <li><a href="#index-idna_005fto_005funicode_005f44i-77"><code>idna_to_unicode_44i</code></a>: <a href="#IDNA-Functions">IDNA Functions</a></li> <li><a href="#index-idna_005fto_005funicode_005f4z4z-81"><code>idna_to_unicode_4z4z</code></a>: <a href="#IDNA-Functions">IDNA Functions</a></li> <li><a href="#index-idna_005fto_005funicode_005f8z4z-82"><code>idna_to_unicode_8z4z</code></a>: <a href="#IDNA-Functions">IDNA Functions</a></li> <li><a href="#index-idna_005fto_005funicode_005f8z8z-83"><code>idna_to_unicode_8z8z</code></a>: <a href="#IDNA-Functions">IDNA Functions</a></li> <li><a href="#index-idna_005fto_005funicode_005f8zlz-84"><code>idna_to_unicode_8zlz</code></a>: <a href="#IDNA-Functions">IDNA Functions</a></li> <li><a href="#index-idna_005fto_005funicode_005flzlz-85"><code>idna_to_unicode_lzlz</code></a>: <a href="#IDNA-Functions">IDNA Functions</a></li> <li><a href="#index-pr29_005f4-101"><code>pr29_4</code></a>: <a href="#PR29-Functions">PR29 Functions</a></li> <li><a href="#index-pr29_005f4z-102"><code>pr29_4z</code></a>: <a href="#PR29-Functions">PR29 Functions</a></li> <li><a href="#index-pr29_005f8z-103"><code>pr29_8z</code></a>: <a href="#PR29-Functions">PR29 Functions</a></li> <li><a href="#index-pr29_005fstrerror-104"><code>pr29_strerror</code></a>: <a href="#PR29-Functions">PR29 Functions</a></li> <li><a href="#index-punycode_002ddecode-114"><code>punycode-decode</code></a>: <a href="#Emacs-API">Emacs API</a></li> <li><a href="#index-punycode_002dencode-113"><code>punycode-encode</code></a>: <a href="#Emacs-API">Emacs API</a></li> <li><a href="#index-punycode_005fdecode-70"><code>punycode_decode</code></a>: <a href="#Punycode-Functions">Punycode Functions</a></li> <li><a href="#index-punycode_005fencode-69"><code>punycode_encode</code></a>: <a href="#Punycode-Functions">Punycode Functions</a></li> <li><a href="#index-punycode_005fstrerror-71"><code>punycode_strerror</code></a>: <a href="#Punycode-Functions">Punycode Functions</a></li> <li><a href="#index-stringprep-59"><code>stringprep</code></a>: <a href="#Stringprep-Functions">Stringprep Functions</a></li> <li><a href="#index-stringprep_005f4i-57"><code>stringprep_4i</code></a>: <a href="#Stringprep-Functions">Stringprep Functions</a></li> <li><a href="#index-stringprep_005f4zi-58"><code>stringprep_4zi</code></a>: <a href="#Stringprep-Functions">Stringprep Functions</a></li> <li><a href="#index-stringprep_005fcheck_005fversion-38"><code>stringprep_check_version</code></a>: <a href="#Version-Check">Version Check</a></li> <li><a href="#index-stringprep_005fconvert-50"><code>stringprep_convert</code></a>: <a href="#Utility-Functions">Utility Functions</a></li> <li><a href="#index-stringprep_005fiscsi-63"><code>stringprep_iscsi</code></a>: <a href="#Stringprep-Functions">Stringprep Functions</a></li> <li><a href="#index-stringprep_005flocale_005fcharset-49"><code>stringprep_locale_charset</code></a>: <a href="#Utility-Functions">Utility Functions</a></li> <li><a href="#index-stringprep_005flocale_005fto_005futf8-51"><code>stringprep_locale_to_utf8</code></a>: <a href="#Utility-Functions">Utility Functions</a></li> <li><a href="#index-stringprep_005fnameprep_005fno_005funassigned-62"><code>stringprep_nameprep_no_unassigned</code></a>: <a href="#Stringprep-Functions">Stringprep Functions</a></li> <li><a href="#index-stringprep_005fplain-64"><code>stringprep_plain</code></a>: <a href="#Stringprep-Functions">Stringprep Functions</a></li> <li><a href="#index-stringprep_005fprofile-60"><code>stringprep_profile</code></a>: <a href="#Stringprep-Functions">Stringprep Functions</a></li> <li><a href="#index-stringprep_005fstrerror-61"><code>stringprep_strerror</code></a>: <a href="#Stringprep-Functions">Stringprep Functions</a></li> <li><a href="#index-stringprep_005fucs4_005fnfkc_005fnormalize-47"><code>stringprep_ucs4_nfkc_normalize</code></a>: <a href="#Utility-Functions">Utility Functions</a></li> <li><a href="#index-stringprep_005fucs4_005fto_005futf8-45"><code>stringprep_ucs4_to_utf8</code></a>: <a href="#Utility-Functions">Utility Functions</a></li> <li><a href="#index-stringprep_005funichar_005fto_005futf8-43"><code>stringprep_unichar_to_utf8</code></a>: <a href="#Utility-Functions">Utility Functions</a></li> <li><a href="#index-stringprep_005futf8_005fnfkc_005fnormalize-48"><code>stringprep_utf8_nfkc_normalize</code></a>: <a href="#Utility-Functions">Utility Functions</a></li> <li><a href="#index-stringprep_005futf8_005fto_005flocale-52"><code>stringprep_utf8_to_locale</code></a>: <a href="#Utility-Functions">Utility Functions</a></li> <li><a href="#index-stringprep_005futf8_005fto_005fucs4-46"><code>stringprep_utf8_to_ucs4</code></a>: <a href="#Utility-Functions">Utility Functions</a></li> <li><a href="#index-stringprep_005futf8_005fto_005funichar-44"><code>stringprep_utf8_to_unichar</code></a>: <a href="#Utility-Functions">Utility Functions</a></li> <li><a href="#index-stringprep_005fxmpp_005fnodeprep-65"><code>stringprep_xmpp_nodeprep</code></a>: <a href="#Stringprep-Functions">Stringprep Functions</a></li> <li><a href="#index-stringprep_005fxmpp_005fresourceprep-66"><code>stringprep_xmpp_resourceprep</code></a>: <a href="#Stringprep-Functions">Stringprep Functions</a></li> <li><a href="#index-tld_005fcheck_005f4-95"><code>tld_check_4</code></a>: <a href="#TLD-Functions">TLD Functions</a></li> <li><a href="#index-tld_005fcheck_005f4t-88"><code>tld_check_4t</code></a>: <a href="#TLD-Functions">TLD Functions</a></li> <li><a href="#index-tld_005fcheck_005f4tz-89"><code>tld_check_4tz</code></a>: <a href="#TLD-Functions">TLD Functions</a></li> <li><a href="#index-tld_005fcheck_005f4z-96"><code>tld_check_4z</code></a>: <a href="#TLD-Functions">TLD Functions</a></li> <li><a href="#index-tld_005fcheck_005f8z-97"><code>tld_check_8z</code></a>: <a href="#TLD-Functions">TLD Functions</a></li> <li><a href="#index-tld_005fcheck_005flz-98"><code>tld_check_lz</code></a>: <a href="#TLD-Functions">TLD Functions</a></li> <li><a href="#index-tld_005fdefault_005ftable-94"><code>tld_default_table</code></a>: <a href="#TLD-Functions">TLD Functions</a></li> <li><a href="#index-tld_005fget_005f4-90"><code>tld_get_4</code></a>: <a href="#TLD-Functions">TLD Functions</a></li> <li><a href="#index-tld_005fget_005f4z-91"><code>tld_get_4z</code></a>: <a href="#TLD-Functions">TLD Functions</a></li> <li><a href="#index-tld_005fget_005ftable-93"><code>tld_get_table</code></a>: <a href="#TLD-Functions">TLD Functions</a></li> <li><a href="#index-tld_005fget_005fz-92"><code>tld_get_z</code></a>: <a href="#TLD-Functions">TLD Functions</a></li> <li><a href="#index-tld_005fstrerror-99"><code>tld_strerror</code></a>: <a href="#TLD-Functions">TLD Functions</a></li> </ul><div class="node"> <p><hr> <a name="Concept-Index"></a> Previous: <a rel="previous" accesskey="p" href="#Function-and-Variable-Index">Function and Variable Index</a>, Up: <a rel="up" accesskey="u" href="#Top">Top</a> </div> <h2 class="unnumbered">Concept Index</h2> <ul class="index-cp" compact> <li><a href="#index-AIX-15">AIX</a>: <a href="#Supported-Platforms">Supported Platforms</a></li> <li><a href="#index-ARM-29">ARM</a>: <a href="#Supported-Platforms">Supported Platforms</a></li> <li><a href="#index-Autoconf-tests-40">Autoconf tests</a>: <a href="#Autoconf-tests">Autoconf tests</a></li> <li><a href="#index-command-line-108">command line</a>: <a href="#Invoking-idn">Invoking idn</a></li> <li><a href="#index-Compiling-your-application-39">Compiling your application</a>: <a href="#Building-the-source">Building the source</a></li> <li><a href="#index-Configure-tests-41">Configure tests</a>: <a href="#Autoconf-tests">Autoconf tests</a></li> <li><a href="#index-Contributing-36">Contributing</a>: <a href="#Contributing">Contributing</a></li> <li><a href="#index-Debian-1">Debian</a>: <a href="#Supported-Platforms">Supported Platforms</a></li> <li><a href="#index-Download-34">Download</a>: <a href="#Downloading-and-Installing">Downloading and Installing</a></li> <li><a href="#index-Examples-105">Examples</a>: <a href="#Examples">Examples</a></li> <li><a href="#index-FDL_002c-GNU-Free-Documentation-License-121">FDL, GNU Free Documentation License</a>: <a href="#GNU-Free-Documentation-License">GNU Free Documentation License</a></li> <li><a href="#index-FreeBSD-23">FreeBSD</a>: <a href="#Supported-Platforms">Supported Platforms</a></li> <li><a href="#index-GPL_002c-GNU-General-Public-License-124">GPL, GNU General Public License</a>: <a href="#GNU-GPL">GNU GPL</a></li> <li><a href="#index-Hacking-37">Hacking</a>: <a href="#Contributing">Contributing</a></li> <li><a href="#index-HP_002dUX-17">HP-UX</a>: <a href="#Supported-Platforms">Supported Platforms</a></li> <li><a href="#index-idn-106"><code>idn</code></a>: <a href="#Invoking-idn">Invoking idn</a></li> <li><a href="#index-IDNA-Functions-72">IDNA Functions</a>: <a href="#IDNA-Functions">IDNA Functions</a></li> <li><a href="#index-Installation-33">Installation</a>: <a href="#Downloading-and-Installing">Downloading and Installing</a></li> <li><a href="#index-invoking-_0040command_007bidn_007d-107">invoking <samp><span class="command">idn</span></samp></a>: <a href="#Invoking-idn">Invoking idn</a></li> <li><a href="#index-IRIX-14">IRIX</a>: <a href="#Supported-Platforms">Supported Platforms</a></li> <li><a href="#index-LGPL_002c-GNU-Lesser-General-Public-License-122">LGPL, GNU Lesser General Public License</a>: <a href="#GNU-LGPL">GNU LGPL</a></li> <li><a href="#index-License_002c-GNU-GPL-125">License, GNU GPL</a>: <a href="#GNU-GPL">GNU GPL</a></li> <li><a href="#index-License_002c-GNU-LGPL-123">License, GNU LGPL</a>: <a href="#GNU-LGPL">GNU LGPL</a></li> <li><a href="#index-MacOS-X-24">MacOS X</a>: <a href="#Supported-Platforms">Supported Platforms</a></li> <li><a href="#index-Mandrake-13">Mandrake</a>: <a href="#Supported-Platforms">Supported Platforms</a></li> <li><a href="#index-Microsoft-31">Microsoft</a>: <a href="#Supported-Platforms">Supported Platforms</a></li> <li><a href="#index-mingw32-32">mingw32</a>: <a href="#Supported-Platforms">Supported Platforms</a></li> <li><a href="#index-Motorola-Coldfire-26">Motorola Coldfire</a>: <a href="#Supported-Platforms">Supported Platforms</a></li> <li><a href="#index-NetBSD-21">NetBSD</a>: <a href="#Supported-Platforms">Supported Platforms</a></li> <li><a href="#index-OpenBSD-22">OpenBSD</a>: <a href="#Supported-Platforms">Supported Platforms</a></li> <li><a href="#index-OpenPower-720-8">OpenPower 720</a>: <a href="#Supported-Platforms">Supported Platforms</a></li> <li><a href="#index-PR29-Functions-100">PR29 Functions</a>: <a href="#PR29-Functions">PR29 Functions</a></li> <li><a href="#index-Punycode-Functions-67">Punycode Functions</a>: <a href="#Punycode-Functions">Punycode Functions</a></li> <li><a href="#index-RedHat-9">RedHat</a>: <a href="#Supported-Platforms">Supported Platforms</a></li> <li><a href="#index-RedHat-Advanced-Server-11">RedHat Advanced Server</a>: <a href="#Supported-Platforms">Supported Platforms</a></li> <li><a href="#index-Reporting-Bugs-35">Reporting Bugs</a>: <a href="#Bug-Reports">Bug Reports</a></li> <li><a href="#index-Solaris-18">Solaris</a>: <a href="#Supported-Platforms">Supported Platforms</a></li> <li><a href="#index-Stringprep-Functions-53">Stringprep Functions</a>: <a href="#Stringprep-Functions">Stringprep Functions</a></li> <li><a href="#index-SuSE-4">SuSE</a>: <a href="#Supported-Platforms">Supported Platforms</a></li> <li><a href="#index-SuSE-Linux-5">SuSE Linux</a>: <a href="#Supported-Platforms">Supported Platforms</a></li> <li><a href="#index-TLD-Functions-87">TLD Functions</a>: <a href="#TLD-Functions">TLD Functions</a></li> <li><a href="#index-Tru64-3">Tru64</a>: <a href="#Supported-Platforms">Supported Platforms</a></li> <li><a href="#index-uClibc-28">uClibc</a>: <a href="#Supported-Platforms">Supported Platforms</a></li> <li><a href="#index-uClinux-27">uClinux</a>: <a href="#Supported-Platforms">Supported Platforms</a></li> <li><a href="#index-Utility-Functions-42">Utility Functions</a>: <a href="#Utility-Functions">Utility Functions</a></li> <li><a href="#index-Windows-16">Windows</a>: <a href="#Supported-Platforms">Supported Platforms</a></li> </ul></body></html>