Announcing ncurses 5.3
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 is encouraging 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
The ncurses distribution is available via anonymous FTP at the
GNU distribution site ftp://ftp.gnu.org/pub/gnu/ncurses.
It is also available at ftp://invisible-island.net/ncurses.
This release is designed to be upward compatible from ncurses
5.0 and 5.2; very few applications will require recompilation,
depending on the platform. These are the highlights from the
change-log since ncurses 5.2 release.
- change type for bool used in headers to
NCURSES_BOOL, which usually is the same as the
compiler's definition for
- add all but two functions for X/Open curses wide-character
support. These are only available if the library is configured
using the --enable-widec option. Missing functions
- add environment variable
$NCURSES_ASSUMED_COLORS to modify the
New features and improvements:
- Improved support for termcap applications:
- add logic to dump_entry.c to remove function-key
definitions that do not fit into the 1023-byte limit for
generated termcaps. This makes hds200 fit.
- modify tgetent() to check if exit_attribute_mode resets
the alternate character set, and if so, attempt to adjust
the copy of the termcap "me" string which it will return to
eliminate that part. In particular, 'screen' would lose
track of line-drawing characters.
- add check/fix to comp_parse.c to suppress warning about
missing acsc string. This happens in configurations where
raw termcap information is processed; tic already does this
and other checks.
- add tic -A option to suppress capabilities which are
commented out when translating to termcap.
- modify logic in lib_baudrate.c for ospeed, for FreeBSD
to make it work properly for termcap applications (patch by
Andrey A Chernov).
- add a call to _nc_keypad() in keypad() to accommodate
applications such as nvi, which use curses for output but not
for input (fixes Debian #131263, cf: 20011215).
- correct logic for COLORFGBG environment variable: if rxvt
is compiled with xpm support, the variable has three fields,
making it slightly incompatible with itself. In either case,
the background color is the last field.
Major bug fixes:
- rewrote limit-checks in wscrl() and associated
_nc_scroll_window(), to ensure that if the parameter of wscrl()
is larger than the size of the scrolling region, then the
scrolling region will be cleared.
- modify tset to restore original I/O modes if an error is
encountered. Also modify to use buffered stderr consistently
rather than mixing with write().
- move calls to def_shell_mode() and def_prog_mode() before
loop with callbacks in lib_set_term.c, since the c++ demo
otherwise initialized the tty modes before saving them.
- modified wresize() to ensure that a failed realloc will not
corrupt the window structure, and to make subwindows fit within
the resized window.
- altered resizeterm() to avoid having it fail when a child
window cannot be resized because it would be larger than its
- correct/improve logic to produce an exit status for errors
in tput, which did not exit with an error when told to put a
string not in the current terminfo entry.
- modify behavior of can_clear_with() so that if an
application is running in a non-bce terminals with default
colors enabled, it returns true, allowing the user to
select/paste text without picking up extraneous trailing
- add a check in relative_move() to guard against buffer
overflow in the overwrite logic.
- add some limit/pointer checks to -S option of tputs.
- modify mvcur() to avoid emitting newline characters when
nonl() mode is set. Normally this is not a problem since the
actual terminal mode is set to suppress nl/crlf translations,
however it is useful to allow the caller to manipulate the
terminal mode to avoid staircasing effects after spawning a
process which writes messages (for lynx 2.8.4).
- configure script:
- modify check in --disable-overwrite option so that it
is used by default unless the --prefix/$prefix value is not
/usr, in attempt to work around packagers who do not read
the INSTALL notes.
- correct a typo in configure --enable-colorfgbg option,
and move it to the experimental section (cf:
- modify configure script to allow building with termcap
only, or with fallbacks only. In this case, we do not build
tic and toe.
- modify run_tic.sh to check if the build is a
cross-compile. In that case, do not use the build's tic to
install the terminfo database.
- modify c++/Makefile.in to accommodate archive programs
that are different for C++ than for C, and add cases for
vendor's C++ compilers on Solaris and IRIX.
- add several configure script options to aid with
cross-compiling: --with-build-cc, --with-build-cflags,
--with-build-ldflags, and --with-build-libs.
- add experimental --with-caps=XXX option to customize to
similar terminfo database formats such as AIX 4.x
- add configure option --with-ospeed to assist packagers
in transition to 5.3 change to ospeed type.
- implement a simple vsscanf() fallback function which
uses the %n conversion to help parse the input data.
- various fixes to build/work with different
implementations of vsscanf().
- add/use macro to suppress sign-extension of char type
on platforms where this is a problem in ctype macros, e.g.,
- finish changes needed to build dll's on cygwin.
- add #undef's before possible redefinition of ERR and OK
- modify ifdef's in write_entry.c to allow use of
symbolic links on platforms with no hard links, e.g.,
- modify _nc_write_entry() to allow for the possibility
that linking aliases on a filesystem that ignores case
would not succeed because the source and destination differ
only by case, e.g., NCR260VT300WPP0 on cygwin.
- modify logic in tic, toe, tput and tset which checks
for basename of argv to work properly on systems such as
OS/2 which have case-independent filenames and/or program
suffixes, e.g., ".ext".
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
- 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
- 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
- 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
- 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
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
- Support for 16-color terminals, such as aixterm and XFree86
- 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
- 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
- An HTML "Introduction to Programming with NCURSES" document
provides a narrative introduction to the curses programming
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
The ncurses code has been tested with a wide variety of
applications including (versions starting with those noted):
- Curses Development Kit
- the underlying application used in Slackware's setup, and
the basis for similar applications on GNU/Linux.
- the character-screen WWW browser
- Midnight Commander
- file manager
- mail utility
- file-transfer utility
- New vi versions 1.50 are able to use ncurses versions 1.9.7
- newsreader, supporting color, MIME
- tape archive utility
- Volks-Hypertext browser for the Jargon File
as well as some that use ncurses for the terminfo support
- terminal emulator
The ncurses distribution includes a selection of test programs
(including a few games).
Who's Who and What's What
The original developers of ncurses are Zeyd Ben-Halim and Eric
S. Raymond. Ongoing work is being done by Thomas Dickey and
Jürgen Pfeifer. Thomas Dickey acts as the maintainer for the
Free Software Foundation, which holds the copyright on ncurses.
Contact the current maintainers at firstname.lastname@example.org.
To join the ncurses mailing list, please write email to
email@example.com containing the line:
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 ftp://invisible-island.net/ncurses.
- Extended-level XPG4 conformance, with internationalization
- 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 includes and uses a version of the
terminfo-format terminal description file maintained by Eric
You can find lots of information on terminal-related topics
not covered in the terminfo file at Richard