'\" '\" Copyright (c) 1998 by Scriptics Corporation. '\" '\" See the file "license.terms" for information on usage and redistribution '\" of this file, and for a DISCLAIMER OF ALL WARRANTIES. '\" '\" RCS: @(#) encoding.n,v 1.5 2003/01/21 19:39:59 hunt Exp '\" .so man.macros .TH encoding n "8.1" Tcl "Tcl Built-In Commands" .BS .SH NAME encoding \- Manipulate encodings .SH SYNOPSIS \fBencoding \fIoption\fR ?\fIarg arg ...\fR? .BE .SH INTRODUCTION .PP Strings in Tcl are encoded using 16-bit Unicode characters. Different operating system interfaces or applications may generate strings in other encodings such as Shift-JIS. The \fBencoding\fR command helps to bridge the gap between Unicode and these other formats. .SH DESCRIPTION .PP Performs one of several encoding related operations, depending on \fIoption\fR. The legal \fIoption\fRs are: .TP \fBencoding convertfrom ?\fIencoding\fR? \fIdata\fR Convert \fIdata\fR to Unicode from the specified \fIencoding\fR. The characters in \fIdata\fR are treated as binary data where the lower 8-bits of each character is taken as a single byte. The resulting sequence of bytes is treated as a string in the specified \fIencoding\fR. If \fIencoding\fR is not specified, the current system encoding is used. .TP \fBencoding convertto ?\fIencoding\fR? \fIstring\fR Convert \fIstring\fR from Unicode to the specified \fIencoding\fR. The result is a sequence of bytes that represents the converted string. Each byte is stored in the lower 8-bits of a Unicode character. If \fIencoding\fR is not specified, the current system encoding is used. .TP \fBencoding names\fR Returns a list containing the names of all of the encodings that are currently available. .TP \fBencoding system\fR ?\fIencoding\fR? Set the system encoding to \fIencoding\fR. If \fIencoding\fR is omitted then the command returns the current system encoding. The system encoding is used whenever Tcl passes strings to system calls. .SH EXAMPLE .PP It is common practice to write script files using a text editor that produces output in the euc-jp encoding, which represents the ASCII characters as singe bytes and Japanese characters as two bytes. This makes it easy to embed literal strings that correspond to non-ASCII characters by simply typing the strings in place in the script. However, because the \fBsource\fR command always reads files using the ISO8859-1 encoding, Tcl will treat each byte in the file as a separate character that maps to the 00 page in Unicode. The resulting Tcl strings will not contain the expected Japanese characters. Instead, they will contain a sequence of Latin-1 characters that correspond to the bytes of the original string. The \fBencoding\fR command can be used to convert this string to the expected Japanese Unicode characters. For example, .CS set s [encoding convertfrom euc-jp "\\xA4\\xCF"] .CE would return the Unicode string "\\u306F", which is the Hiragana letter HA. .SH "SEE ALSO" Tcl_GetEncoding(3) .SH KEYWORDS encoding