Announcing ncurses 5.5
The ncurses (new curses) library is a free software emulation of
curses in System V Release 4.0, and more. It uses terminfo format,
supports pads and color and multiple highlights and forms characters
and function-key mapping, and has all the other SYSV-curses
enhancements over BSD curses.
In mid-June 1995, the maintainer of 4.4BSD curses declared that he
considered 4.4BSD curses obsolete, and encouraged the keepers of Unix
releases such as BSD/OS, FreeBSD and NetBSD to switch over to ncurses.
The ncurses code was developed under GNU/Linux. It has been in use for
some time with OpenBSD as the system curses library, and on FreeBSD
and NetBSD as an external package. It should port easily to any
ANSI/POSIX-conforming UNIX. It has even been ported to OS/2 Warp!
The distribution includes the library and support utilities, including
a terminfo compiler tic(1), a decompiler infocmp(1), clear(1),
tput(1), tset(1), and a termcap conversion tool captoinfo(1). Full
manual pages are provided for the library and tools.
The ncurses distribution is available via anonymous FTP at the GNU
distribution site [1]ftp://ftp.gnu.org/gnu/ncurses/ .
It is also available at [2]ftp://invisible-island.net/ncurses/ .
Release Notes
This release is designed to be upward compatible from ncurses 5.0
through 5.4; very few applications will require recompilation,
depending on the platform. These are the highlights from the
change-log since ncurses 5.4 release.
Interface changes:
* terminfo installs "xterm-new" as "xterm" entry rather than
"xterm-old" (aka xterm-r6).
* terminfo data is installed using the tic -x option (few systems
still use ncurses 4.2).
* modify C++ binding to work with newer C++ compilers by providing
initializers and using modern casts. Old-style header names are
still used in this release to allow compiling with not-so-old
compilers.
* modify parameter type in c++ binding for insch() and mvwinsch() to
be consistent with underlying ncurses library (was char, is
chtype).
* change NCursesWindow::err_handler() to a virtual function.
* form and menu libraries now work with wide-character data.
Applications which bypassed the form library and manipulated the
FIELD.buf data directly will not work properly with libformw,
since that no longer points to an array of char. The
set_field_buffer() and field_buffer() functions translate to/from
the actual field data.
* add symbol to curses.h which can be used to suppress include of
stdbool.h, e.g.,
#define NCURSES_ENABLE_STDBOOL_H 0
#include <curses.h>
* change SP->_current_attr to a pointer, adjust ifdef's to ensure
that libtinfo.so and libtinfow.so have the same ABI. The reason
for this is that the corresponding data which belongs to the
upper-level ncurses library has a different size in each model.
* winnstr() now returns multibyte character strings for the
wide-character configuration.
* assume_default_colors() no longer requires that
use_default_colors() be called first.
* data_ahead() now works with wide-characters.
* slk_set() and slk_wset() now accept and store multibyte or
multicolumn characters.
* start_color() now returns OK if colors have already been started.
start_color() also returns ERR if it cannot allocate memory.
* pair_content() now returns -1 for consistency with init_pair() if
it corresponds to the default-color.
* unctrl() now returns null if its parameter does not correspond to
an unsigned char.
New features and improvements:
* library
+ environment variable NCURSES_NO_UTF8_ACS supports
miscellaneous terminal emulators which ignore alternate
character set escape sequences when in UTF-8 mode.
+ modify initialization of key lookup table so that if an
extended capability (tic -x) string is defined, and its name
begins with 'k', ncurses will automatically treat it as a
key.
+ change GPM initialization, using dl library to load it
dynamically at runtime.
+ form, menu and panel libraries support debug-tracing.
* add NCURSES-Programming-HOWTO.html by Pradeep Padala (see
http://tldp.org/HOWTO/NCURSES-Programming-HOWTO/).
* programs:
* infocmp:
+ The -i option now matches 8-bit controls against its table
entries, e.g., so it can analyze the xterm-8bit entry.
+ add "-x" option to infocmp like tic's "-x", for use in "-F"
comparisons. This modifies infocmp to only report extended
capabilities if the -x option is given, making this more
consistent with tic. Some scripts may break, since infocmp
previous gave this information without an option.
* tic:
+ modify termcap-parsing to retain 2-character aliases at the
beginning of an entry if the "-x" option is used in tic.
+ filter out long extended names when translating to termcap
format. Only two characters are permissible for termcap
capability names.
+ correct translation of "%%" in terminfo format to termcap,
e.g., using "tic -C".
+ modify the "-c -v" options to ignore delays when comparing
strings. Also modify it to ignore a canceled sgr string,
e.g., for terminals which cannot properly combine attributes
in one control sequence.
+ add a check for improperly ended strings, i.e., where a
following line begins in column 1.
+ add a check in tic for terminfo entries having an sgr0 but no
sgr string. This confuses Tru64 and HPUX curses when combined
with color, e.g., making them leave line-drawing characters
in odd places.
+ add check (with debug configuration) that provides about the
runtime changes that would be made to sgr0 for termcap
applications.
* tset:
+ add -c and -w options to allow user to suppress ncurses'
resizing of the terminal emulator window in the special case
where it is not able to detect the true size.
Major bug fixes:
* improve logic in tgetent() which adjusts the termcap "me" string
to work with ISO-2022 string used in xterm-new. This is a feature
that was incompletely implemented in ncurses 5.3. ncurses attempts
to provide termcap clients with the portion of the sgr0 (termcap
"me") string that does not reset line-drawing.
* cells in the WINDOW which are continuations of a multicolumn
character are encoded differently, making repainting more
reliable.
* amend change to setupterm() in ncurses 5.4 (20030405) which would
reuse the value of cur_term if the same output was selected. This
now reuses it only when setupterm() is called from tgetent(),
which has no notion of separate SCREENs. Note that tgetent() must
be called after initscr() or newterm() to use this feature.
* make setcchar() now works when its wchar_t* parameter is pointing
to a string which contains more data than can be converted.
* win_wchnstr() now works for more than one cell.
* resizeterm() now processes all levels of window hierarchy.
* disable GPM mouse support when $TERM happens to be prefixed with
"xterm". Gpm_Open() would otherwise assert that it can deal with
mouse events in this case.
* add SP->_screen_acs_map[], used to ensure that mapping of missing
line-drawing characters is handled properly. For example,
ACS_DARROW is absent from xterm-new, and it was coincidentally
displayed the same as ACS_BTEE.
Portability:
* configure script:
+ new options:
--enable-largefile
set compiler and linker flags to use largefile
support.
--enable-ext-colors
Allow encoding of 256 foreground and background
colors, e.g., with the xterm-256color or
xterm-88color terminfo entries. This requires ABI 6
because it changes the size of cchar_t.
--enable-ext-mouse
This defines NCURSES_MOUSE_VERSION 2, and modifies
the encoding of mouse events to support wheel mice,
which may transmit buttons 4 and 5. This works with
xterm and similar terminal emulators. This requires
ABI 6 because it changes the encoding of mouse
events.
--with-chtype
overriding of the non-LP64 model's use of chtype
--with-mmask-t
overriding of the non-LP64 model's use of mmask_t
--without-xterm-new
Installs "xterm-old" as the "xterm" entry of the
terminfo database.
+ The --with-termlib option now accepts a value which sets the
name of the terminfo library. This would allow a packager to
build libtinfow.so renamed to coincide with libtinfo.so
+ fixes/improvements for cross-compiling:
o suppress $suffix in misc/run_tic.sh when
cross-compiling. This allows cross-compiles to use the
host's tic program to handle the "make install.data"
step.
o correct BUILD_CPPFLAGS substitution in
ncurses/Makefile.in, to allow cross-compiling from a
separate directory tree.
* library:
+ add ifdef's for _LP64 in curses.h to avoid using wasteful
64-bits for chtype and mmask_t, but add configure option
--disable-lp64 in case anyone used that configuration.
+ modify C++ binding to use some C internal functions to make
it compile properly on Solaris (and other platforms).
+ remove check in newwin() that prevents allocating windows
that extend beyond the screen (Solaris does this).
+ check for nl_langinfo(CODESET), use it if available. This
replaces ad hoc tests of environment variables to check if
the terminal is setup for UTF-8 encoding. Applications which
do not call setlocale() should be corrected, to make them
work properly with UTF-8 encoding.
In particular, applications which assume (and do not call
setlocale()) that Latin-1 codes are printable will no longer
work in a UTF-8 locale since the ad hoc check of environment
variables to see if the locale was UTF-8 is not used when
nl_langinfo(CODESET) is available.
+ use setlocale() to query the program's current locale rather
than using getenv(). This supports applications which rely
upon legacy treatment of 8-bit characters when the locale is
not initialized.
Features of Ncurses
The ncurses package is fully compatible with SVr4 (System V Release 4)
curses:
* All 257 of the SVr4 calls have been implemented (and are
documented).
* Full support for SVr4 curses features including keyboard mapping,
color, forms-drawing with ACS characters, and automatic
recognition of keypad and function keys.
* An emulation of the SVr4 panels library, supporting a stack of
windows with backing store, is included.
* An emulation of the SVr4 menus library, supporting a uniform but
flexible interface for menu programming, is included.
* An emulation of the SVr4 form library, supporting data collection
through on-screen forms, is included.
* Binary terminfo entries generated by the ncurses tic(1)
implementation are bit-for-bit-compatible with the entry format
SVr4 curses uses.
* The utilities have options to allow you to filter terminfo entries
for use with less capable curses/terminfo versions such as the
HP/UX and AIX ports.
The ncurses package also has many useful extensions over SVr4:
* The API is 8-bit clean and base-level conformant with the X/OPEN
curses specification, XSI curses (that is, it implements all BASE
level features, but not all EXTENDED features). Most
EXTENDED-level features not directly concerned with wide-character
support are implemented, including many function calls not
supported under SVr4 curses (but portability of all calls is
documented so you can use the SVr4 subset only).
* Unlike SVr3 curses, ncurses can write to the rightmost-bottommost
corner of the screen if your terminal has an insert-character
capability.
* Ada95 and C++ bindings.
* Support for mouse event reporting with X Window xterm and OS/2
console windows.
* Extended mouse support via Alessandro Rubini's gpm package.
* The function wresize() allows you to resize windows, preserving
their data.
* The function use_default_colors() allows you to use the terminal's
default colors for the default color pair, achieving the effect of
transparent colors.
* The functions keyok() and define_key() allow you to better control
the use of function keys, e.g., disabling the ncurses KEY_MOUSE,
or by defining more than one control sequence to map to a given
key code.
* Support for 16-color terminals, such as aixterm and XFree86 xterm.
* Better cursor-movement optimization. The package now features a
cursor-local-movement computation more efficient than either BSD's
or System V's.
* Super hardware scrolling support. The screen-update code
incorporates a novel, simple, and cheap algorithm that enables it
to make optimal use of hardware scrolling, line-insertion, and
line-deletion for screen-line movements. This algorithm is more
powerful than the 4.4BSD curses quickch() routine.
* Real support for terminals with the magic-cookie glitch. The
screen-update code will refrain from drawing a highlight if the
magic- cookie unattributed spaces required just before the
beginning and after the end would step on a non-space character.
It will automatically shift highlight boundaries when doing so
would make it possible to draw the highlight without changing the
visual appearance of the screen.
* It is possible to generate the library with a list of pre-loaded
fallback entries linked to it so that it can serve those terminal
types even when no terminfo tree or termcap file is accessible
(this may be useful for support of screen-oriented programs that
must run in single-user mode).
* The tic(1)/captoinfo utility provided with ncurses has the ability
to translate many termcaps from the XENIX, IBM and AT&T extension
sets.
* A BSD-like tset(1) utility is provided.
* The ncurses library and utilities will automatically read terminfo
entries from $HOME/.terminfo if it exists, and compile to that
directory if it exists and the user has no write access to the
system directory. This feature makes it easier for users to have
personal terminfo entries without giving up access to the system
terminfo directory.
* You may specify a path of directories to search for compiled
descriptions with the environment variable TERMINFO_DIRS (this
generalizes the feature provided by TERMINFO under stock System
V.)
* In terminfo source files, use capabilities may refer not just to
other entries in the same source file (as in System V) but also to
compiled entries in either the system terminfo directory or the
user's $HOME/.terminfo directory.
* A script (capconvert) is provided to help BSD users transition
from termcap to terminfo. It gathers the information in a TERMCAP
environment variable and/or a ~/.termcap local entries file and
converts it to an equivalent local terminfo tree under
$HOME/.terminfo.
* Automatic fallback to the /etc/termcap file can be compiled in
when it is not possible to build a terminfo tree. This feature is
neither fast nor cheap, you don't want to use it unless you have
to, but it's there.
* The table-of-entries utility toe makes it easy for users to see
exactly what terminal types are available on the system.
* The library meets the XSI requirement that every macro entry point
have a corresponding function which may be linked (and will be
prototype-checked) if the macro definition is disabled with
#undef.
* An HTML "Introduction to Programming with NCURSES" document
provides a narrative introduction to the curses programming
interface.
State of the Package
Numerous bugs present in earlier versions have been fixed; the library
is far more reliable than it used to be. Bounds checking in many
`dangerous' entry points has been improved. The code is now type-safe
according to gcc -Wall. The library has been checked for malloc leaks
and arena corruption by the Purify memory-allocation tester.
The ncurses code has been tested with a wide variety of applications
including (versions starting with those noted):
cdk
Curses Development Kit
[3]http://invisible-island.net/cdk/
[4]http://www.vexus.ca/products/CDK/
ded
directory-editor
[5]http://invisible-island.net/ded/
dialog
the underlying application used in Slackware's setup, and the
basis for similar applications on GNU/Linux.
[6]http://invisible-island.net/dialog/
lynx
the character-screen WWW browser
[7]http://lynx.isc.org/release/
Midnight Commander
file manager
[8]http://www.ibiblio.org/mc/
mutt
mail utility
[9]http://www.mutt.org/
ncftp
file-transfer utility
[10]http://www.ncftp.com/
nvi
New vi versions 1.50 are able to use ncurses versions 1.9.7 and
later.
[11]http://www.bostic.com/vi/
pinfo
Lynx-like info browser.
[12]http://dione.ids.pl/~pborys/software/pinfo/
tin
newsreader, supporting color, MIME [13]http://www.tin.org/
vh-1.6
Volks-Hypertext browser for the Jargon File
[14]http://www.debian.org/Packages/unstable/text/vh.html
as well as some that use ncurses for the terminfo support alone:
minicom
terminal emulator
[15]http://www.netsonic.fi/~walker/minicom.html
vile
vi-like-emacs
[16]http://invisible-island.net/vile/
The ncurses distribution includes a selection of test programs
(including a few games).
Who's Who and What's What
Zeyd Ben-Halim started it from a previous package pcurses, written by
Pavel Curtis. Eric S. Raymond continued development. Jürgen Pfeifer
wrote most of the form and menu libraries. Ongoing work is being done
by [17]Thomas Dickey. Thomas Dickey acts as the maintainer for the
Free Software Foundation, which holds the copyright on ncurses.
Contact the current maintainers at [18]bug-ncurses@gnu.org.
To join the ncurses mailing list, please write email to
bug-ncurses-request@gnu.org containing the line:
subscribe <name>@<host.domain>
This list is open to anyone interested in helping with the development
and testing of this package.
Beta versions of ncurses and patches to the current release are made
available at [19]ftp://invisible-island.net/ncurses/ .
Future Plans
* Extended-level XPG4 conformance, with internationalization
support.
* Ports to more systems, including DOS and Windows.
We need people to help with these projects. If you are interested in
working on them, please join the ncurses list.
Other Related Resources
The distribution provides a newer version of the terminfo-format
terminal description file maintained by [20]Eric Raymond . Unlike the
older version, the termcap and terminfo data are provided in the same
file.
You can find lots of information on terminal-related topics not
covered in the terminfo file at [21]Richard Shuford's archive .
References
1. ftp://ftp.gnu.org/gnu/ncurses/
2. ftp://invisible-island.net/ncurses/
3. http://invisible-island.net/cdk/
4. http://www.vexus.ca/products/CDK/
5. http://invisible-island.net/ded/
6. http://invisible-island.net/dialog/
7. http://lynx.isc.org/release/
8. http://www.ibiblio.org/mc/
9. http://www.mutt.org/
10. http://www.ncftp.com/
11. http://www.bostic.com/vi/
12. http://dione.ids.pl/~pborys/software/pinfo/
13. http://www.tin.org/
14. http://www.debian.org/Packages/unstable/text/vh.html
15. http://www.netsonic.fi/~walker/minicom.html
16. http://invisible-island.net/vile/
17. mailto:dickey@invisible-island.net
18. mailto:bug-ncurses@gnu.org
19. ftp://invisible-island.net/ncurses/
20. http://www.catb.org/~esr/terminfo/
21. http://www.cs.utk.edu/~shuford/terminal_index.html