Announcing ncurses 5.1
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 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://dickey.his.com/ncurses.
This release is designed to be upward compatible from ncurses
5.0; very few applications will require recompilation, depending
on the platform. These are the highlights from the change-log
since ncurses 5.0 release.
- made the extended terminal capabilities
configure --enable-tcap-names) a standard
feature (though the configure script can disable it, it is
built by default).
- removed the
trace() function and related trace
support from the production library. This is the only interface
change that may cause problems with existing applications
linked to shared libraries, since not all platforms use the
minor version number.
- explicitly initialized to zero several data items which
were implicitly initialized, e.g., cur_term. If not explicitly
initialized, their storage type is C (common), and causes
problems linking on some platforms.
- modified curses.h.in, undef'ing some symbols to avoid
conflict with C++ STL.
Major bug fixes:
- modified infocmp -e, -E options to ensure that generated
fallback.c type for Booleans agrees with term.h
- documented a special case of incompatiblity between ncurses
4.2 and 5.0, added a section for this in INSTALL.
- corrected tests for file-descriptors in OS/2 EMX mouse
support. A negative value could be used by FD_SET, causing the
select() call to wait indefinitely.
- made 'tput flash' work properly for xterm by flushing
output in delay_output() when using napms(), and modifying
xterm's terminfo to specify no padding character. Otherwise,
xterm's reported baud rate could mislead ncurses into producing
too few padding characters.
- modified lib_addch.c to allow repeated update to the
lower-right corner, rather than displaying only the first
character written until the cursor is moved. Recent versions of
SVr4 curses can update the lower-right corner, and behave this
- modified echo() behavior of getch() to match Solaris curses
for carriage return and backspace (reported by Neil
- corrected offsets used for subwindows in
- modified configure script so AC_MSG_ERROR is temporarily
defined to a warning in AC_PROG_CXX to make it recover from a
missing C++ compiler without requiring user to add
- corrected logic in lib_twait.c as used by lib_mouse.c for
GPM mouse support when poll() is used rather than
- made several fixes for buffer overflows, unchecked
recursion, improvements in performance, etc. See the NEWS file
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 4.1
- 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
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://dickey.his.com/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