Announcing ncurses 5.4
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/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 5.3; very few applications will require recompilation,
depending on the platform. These are the highlights from the
change-log since ncurses 5.3 release.
New features and improvements:
- implement logic in lib_mouse.c to handle position
reports which are generated when XFree86 xterm is
initialized with private modes 1002 or 1003. These are
returned to the application as the REPORT_MOUSE_POSITION
mask, which was not implemented.
- modify soft-key initialization to use A_REVERSE if
A_STANDOUT would not be shown when colors are used, i.e.,
if ncv#1 is set in the terminfo as is done in
- add configure option for FreeBSD sysmouse,
--with-sysmouse, and implement library support for
- allow it to run from fallback terminfo data.
- reset colors after each color test, correct a place
exit_standout_mode was used instead
bce test by making it set
colors other than black on white.
- handle a case where an entry has no description,
and capabilities begin on the same line as the entry
- allow a terminfo entry with a leading 2-character
- improved warnings when suppressing items to fit in
termcap's 1023-byte limit.
- add check for multiple "tc=" clauses in a
- correct logic for resolving "use=" clauses allow
infocmp and tic to show cancelled capabilities.
- check for incomplete line-drawing character
- check for missing/empty/illegal terminfo name.
- modify tput to use the same parameter analysis as
tparm() does, to provide for user-defined strings,
e.g., for xterm title, a corresponding capability might
- use the system's default values for CKILL and other
default control characters.
- correct interchanged defaults for kill and
interrupt characters, which caused it to report
Major bug fixes:
- prevent recursion in wgetch() via wgetnstr() if the
connection cannot be switched between cooked/raw modes because
it is not a TTY.
- correct a case in _nc_remove_string(), used by
define_key(), to avoid infinite loop if the given
string happens to be a substring of other strings which are
assigned to keys.
- modify logic of acsc to use the original character if no
mapping is defined, rather than a null.
- several improvements for handling multi-cell display of
- modify setcchar() to allow converting control
characters to complex characters.
- correct handling of multibyte characters in
waddch_literal() which force wrapping because they are
started too late on the line.
- modify setcchar() to allow for wchar_t input strings
that have more than one spacing character.
- other fixes for wide-character support:
- rewrote lib_acs.c to allow PutAttrChar() to decide how
to render alternate-characters, i.e., to work with Linux
console and UTF-8 locale.
- implement a workaround so that line-drawing works with
screen's crippled UTF-8 support (tested with 3.9.13). This
only works with the wide-character support
(--enable-widec); the normal library will simply suppress
line-drawing when running in a UTF-8 locale in screen.
- corrections to lib_get_wstr.c:
- null-terminate buffer passed to setcchar(), which
- map special characters such as erase- and
kill-characters into key-codes so those will work as
expected even if they are not mentioned in the
setupterm() to check if the terminfo
and terminal-modes have already been read. This ensures that it
does not reinvoke
def_prog_mode() when an
application calls more than one function, such as
- fix form_driver() cases for REQ_CLR_EOF, REQ_CLR_EOL,
REQ_DEL_CHAR, REQ_DEL_PREV and REQ_NEW_LINE, which did not
ensure the cursor was at the editing position before making
keybound(), which reported definitions
in the wrong table, i.e., the list of definitions which are
- fixes related to safe_sprintf.c:
- correct an allocation size in safe_sprintf.c for the
"*" format code.
- correct safe_sprintf.c to not return a null pointer if
the format happens to be an empty string.
- make return value from _nc_printf_string() consistent.
Before, depending on whether --enable-safe-sprintf was
used, it might not be cached for reallocating.
- other low-level improvements to the optimization code
- if the output is a socket or other non-tty device, use
1 millisecond for the cost in mvcur; previously it was 9
milliseconds because the baudrate was not known.
- modify lib_getch.c to avoid recursion via wgetnstr()
when the input is not a tty and consequently mode-changes
do not work.
- fix several places in tack/pad.c which tested and used
the parameter- and parameterless strings
- change several tputs() calls in scrolling code to use
putp(), to enable padding which may be needed for some
- improve mvcur() by checking if it is safe to move when
video attributes are set (msgr), and if not, reset/restore
attributes within that function rather than doing it
separately in the GoTo() function in tty_update.c.
- use tputs() rather than putp() in a few cases in
tty_update.c since the corresponding delays are
proportional to the number of lines affected: repeat_char,
- correct line/column reference in adjust_window(), needed to
make special windows such as curscr track properly when
- fix a potential recursion between napms() and
- rewrote lib_insch.c, combining it with lib_insstr.c so both
handle tab and other control characters consistently.
- do not try to open gpm mouse driver if standard output is
not a tty; the gpm library does not make this check.
- configure script:
- new options:
- --with-abi-version option.
- addresses platforms where packagers have diverged
from ncurses ABI numbering.
- addresses behavior of BSDI, allow install of
man+cat files on NetBSD, whose behavior has diverged by
requiring both to be present.
- extends "--with-manpage-aliases" to provide the
option of generating ".so" files rather than symbolic
links for manpage aliases.
- workaround to force libtool on Darwin generate the
"same" library names as with the "--with-shared"
option. The Darwin ld program does not work well with a
zero as the minor-version value.
- simplifies defining TRACE to incorporate trace() in
- fixes/improvements for cross-compiling:
- allow BUILD_CC and related configure script
variables to be overridden from the environment.
- use AC_CHECK_TOOL to get proper values for AR and
LD for cross compiling.
$cross_compiling variable in
configure script rather than comparing
alias, since "host" is traditionally misused in
autoconf to refer to the target platform.
- modify run_tic.in to avoid using wrong shared
libraries when cross-compiling.
- fixes for Mac OS X:
- fix a redefinition of
$RANLIB in the
configure script when libtool is used.
- modify MKlib_gen.sh to avoid passing "#" tokens
through the C preprocessor. This works around Mac OS
X's preprocessor, which insists on adding a blank on
each side of the token.
- workarounds for broken tools:
- add configure check for wchar_t and wint_t types,
rather than rely on preprocessor definitions. Also work
around for gcc
fixinclude bug which
creates a shadow copy of curses.h if it sees these
symbols apparently typedef'd.
- modify configure script to omit -Winline for gcc
3.3, since that feature is broken.
- several script fixes to work around the ironically
named POSIXLY_CORRECT feature of GNU sed
- modify configure script to avoid using "head -1",
which does not work if POSIXLY_CORRECT (sic) is
- update configure script to reflect fix for
AC_PROG_GCC_TRADITIONAL, which is broken in autoconf
2.5x for Mac OS X 10.2.3.
- repair check for missing C++ compiler, which is
broken in autoconf 2.5x by hardcoding it to g++.
- corrected ifdef's relating to configure check for
- remove configure script check to allow -Wconversion for
older versions of gcc
- modify configure script to accommodate libtool 1.5, as
well as add an parameter to the "--with-libtool" option
which can specify the pathname of libtool.
- change several sed scripts to avoid using "\+" since it
is not a BRE (basic regular expression). One instance
caused terminfo.5 to be misformatted on FreeBSD.
- use '%' as sed substitute delimiter in run_tic script
to avoid problems with pathname delimiters such as ':' and
- add -D_XOPEN_SOURCE=500 if needed when configuring with
"--enable-widec", to get
on HPUX 11.11.
- adjust include-options in CF_ETIP_DEFINES to avoid
missing ncurses_dll.h, fixing special definitions that may
be needed for etip.h.
- modify CF_LIB_SUFFIX for Itanium releases of HP-UX,
which use a ".so" suffix.
- improve ifdef's to guard against redefinition of
wchar_t and wint_t in curses.h.
- remove an #undef for KEY_EVENT from curses.tail used in
the experimental NCURSES_WGETCH_EVENTS feature. The #undef
dpkg's build script.
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
- Lynx-like info browser. http://dione.ids.pl/~pborys/software/pinfo/
- newsreader, supporting color, MIME http://www.tin.org/
- 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
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 Thomas Dickey. 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 provides a newer version of the
terminfo-format terminal description file maintained by 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 Richard
Shuford's archive .