The ncurses (new curses) library is a freeware emulation of System V
Release 4.0 curses. 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.
The ncurses code was developed under 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 tools.
FEATURES OF NCURSES
The ncurses package is fully compatible with SVr4 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 System V Release 4 panels library, supporting
a stack of windows with backing store, is included.
- An emulation of the System V Release 4 menus library, supporting a
uniform but flexible interface for menu programming, is included.
- An emulation of the System V Release 4 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 SVr4 curses, ncurses can write to the rightmost-bottommost
corner of the screen if your terminal has an insert-character
- (PC-clone boxes only) Support for access to the IBM PC ROM
characters 0-32 through the highlight A_ALTCHARSET.
- Support for mouse event reporting under xterm.
- The function wresize() allows you to resize windows, preserving
- 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.
- 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
- 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
- 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
- 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
- An HTML "Introduction to Programming with NCURSES" document
provides a narrative introduction to the curses programming