Announcing ncurses 4.0The 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.
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 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.
The ncurses distribution is available via anonymous FTP at:
ftp://ftp.netcom.com/pub/zm/zmbenhal/ncurses.
It is also carried on the GNU distribution site at ftp://prep.ai.mit.edu/pub/gnu.
Features of ncurses
The ncurses package is fully
compatible with SVr4 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 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 capability.
- (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 their data.
- 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:
- ded
- directory-editor ftp://ftp.clark.net/pub/dickey/ded.
- dialog
- the underlying application used in Slackware's setup, and
the basis for similar applications on Linux.
- lynx-2.6
- the character-screen WWW browser
- ncftp 2.0
- file-transfer utility
- nvi
- New vi versions 1.50 are able to use ncurses versions 1.9.7
and later.
- taper
- tape archive utility
- vh-1.6
- Volks-Hypertext browser for the Jargon File
as well as some that use ncurses for the terminfo support
alone:
- minicom-1.75
- terminal emulator
- tin-unoff
- tin (unofficial) newsreader, supporting color, MIME
ftp://ftp.akk.uni-karlsruhe.de/pub/news/clients/tin-unoff.
- vile
- vi-like-emacs ftp://ftp.clark.net/pub/dickey/vile.
The ncurses distribution includes a selection of test programs
(including a few games).
Who's Who and What's What
The original maintainer of
ncurses is Zeyd
Ben-Halim. Unfortunately, he can only work on the package
part time. As a result, since 1.8.1, much of the enhancement work
and documentation has been done by Eric S. Raymond. The
current primary maintainers are Thomas Dickey and Juergen Pfeifer.
However, requests for beta releases and other queries should
properly be directed to Zeyd.
There is an ncurses mailing list. It is a majordomo list; to
join, write to listserv@netcom.com with a message
containing the line:
subscribe ncurses-list <name>@<host.domain>
This list is open to anyone interested in helping with the
development and testing of this package.
Beta versions of ncurses are made available at ftp://ftp.clark.net/pub/dickey/ncurses.
Future Plans
- Extended mouse support via Alessandro Rubini's gpm
package.
- 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.
The terminfo/termcap Database
The distribution includes
and uses a copy of the terminfo-format terminal description file
maintained by Eric Raymond. You can download either the termcap
or terminfo
versions of the terminal-type database from Eric's ncurses page,
http://www.ccil.org/~esr/ncurses.html.
Other Related Resources
You can find lots of information
on terminal-related topics not covered in the terminfo file at
Richard
Shuford's archive.