https://invisible-island.net/ncurses/


Announcing ncurses 6.3

Overview

The ncurses (new curses) library is a free software emulation of curses in System V Release 4.0 (SVr4), 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 SVr4-curses enhancements over BSD curses. SVr4 curses became the basis of X/Open Curses.

In mid-June 1995, the maintainer of 4.4BSD curses declared that he considered 4.4BSD curses obsolete, and encouraged the keepers of unix releases such as BSD/OS, FreeBSD and NetBSD to switch over to ncurses.

Since 1995, ncurses has been ported to many systems:

The distribution includes the library and support utilities, including

Full manual pages are provided for the library and tools.

The ncurses distribution is available at ncurses' homepage:

ftp://ftp.invisible-island.net/ncurses/ or
https://invisible-mirror.net/archives/ncurses/ .

It is also available via anonymous FTP at the GNU distribution site

ftp://ftp.gnu.org/gnu/ncurses/ .

Release Notes

These notes are for ncurses 6.3, released October 21, 2021.

This release is designed to be source-compatible with ncurses 5.0 through 6.2; providing extensions to the application binary interface (ABI). Although the source can still be configured to support the ncurses 5 ABI, the reason for the release is to reflect improvements to the ncurses 6 ABI and the supporting utility programs.

There are, of course, numerous other improvements, listed in this announcement.

The most important bug-fixes/improvements dealt with portability issues. The release notes also mention some other bug-fixes, but are focused on new features and improvements to existing features since ncurses 6.2 release.

Library improvements

New features

There are a few new features:

Additionally, to improve performance other changes (and extensions) are provided in this release:

Other improvements

These are revised features:

These were done to limit or ultimately deprecate features:

These are improvements to existing features:

These are corrections to existing features:

Program improvements

Several improvements were made to the utility programs:

tabs
tic
toe
tput

Examples

Along with the library and utilities, improvements were made to the ncurses-examples. Most of this activity aimed at improving the test-packages. A few changes are more generally useful, e.g., for the main ncurses test-program, and for analyzing traces using the tracemunch script:

There are other new demo/test programs and reusable examples:

back_ground
to exercise the wide-character background functions.
move_field
to demonstrate move_field, and a stub for a corresponding demo of dup_field.
test_tparm
for checking tparm changes.

Terminal database

There are several new terminal descriptions:

absolute, att610+cvis, foot, foot-direct, hp98550-color, hpterm-color2, hterm, hterm-256color, linux-s, putty+keypad, putty+screen, putty-screen, screen.linux-s, scrt/securecrt, tmux-direct, vt220+cvis, vt220+cvis8, vt220+pcedit, vt220+vtedit, vt220-base, vt52+keypad, xterm+256color2, xterm+88color2, xterm-direct16, xterm-direct256, xterm+nofkeys, and xterm+nopcfkeys.

There are many changes to existing terminal descriptions. Some were updates to several descriptions:

while others affected specific descriptions. These were retested, to take into account changes by their developers:

kitty+common, mlterm3, ms-terminal

while these are specific fixes based on reviewing documentation, user reports, or warnings from tic:

aaa+dec, aaa+rv
correct rmacs/smacs
aaa+rv
correct sgr
icl6404
correct csr
kitty
use att610+cvis, xterm+tmux and ansi+enq
konsole-base
re-enable "bel"
linux2.6
fix pound-sign mapping in acsc
linux3.0
modify to reflect default mapping of shift-tab by kbd 1.14
pccons
fill in some missing pieces, to make it comparable to the vt220 entry
putty
use vt100+fnkeys, add rep
screen
use vt100+enq
terminator
corrected tsl capability
ti916
correct cup
tmux
change kbs to ^?
vt220
use vt220+cvis
vt420+lrmm
add smglp and smgrp
vt420
use vt420+lrmm
xterm-new
add nel
xterm-vt52
use vt52+keypad

A few entries use extensions (user-defined terminal capabilities):

Documentation

As usual, this release

In addition to providing background information to explain these features and show how they evolved, there are corrections, clarifications, etc.:

There are no new manual pages (all of the manual page updates are to existing pages).

Some of the improvements are more subtle, relating to the way the information is presented. For instance, hyphenation is suppressed in the HTML files generated from manual pages because an upgrade to groff gave noticeably poorer results, interfering with the process of creating links between the resulting webpages.

Interesting bug-fixes

While there were many bugs fixed during development of ncurses 6.3, only a few (the reason for this release) were both important and interesting. Most of the bug-fixes were for local issues which did not affect compatibility across releases. Since those are detailed in the NEWS file no elaboration is needed here.

The interesting bugs were:

Configuration changes

Major changes

There are no major changes. Several new options were added to ease integration of packages with systems using different versions of GNAT and ncurses. Also, improvements were made to configure checks.

Configuration options

There are a few new/modified configure options:

--enable-fvisibility

new configure option and check for gcc -fvisibility=hidden feature

--enable-leaks

corrected to allow turning leak-checking off later in a set of options.

--enable-stdnoreturn

new configure option makes the _Noreturn keyword optional to ease transition.

--disable-pkg-ldflags

revised option also controls whether $LDFLAGS from the build is provided in “-config” and “.pc” files.

--disable-root-access

add configure option which tells ncurses to disallow most file-opens by setuid processes.

--disable-wattr-macros

changed default to help packagers who reuse wide ncursesw header file with non-wide ncurses library.

--with-pkg-config-libdir

revised option uses the actual search path from pkg-config or pkgconf using the output from --debug.

--with-ada-libname
--with-form-libname
--with-menu-libname
--with-panel-libname

new several --with-xxx-libname options, to help with pkgsrc

Portability

Many of the portability changes are implemented via the configure script:

Here are some of the other portability fixes:


Features of ncurses

The ncurses package is fully upward-compatible with SVr4 (System V Release 4) curses:

The ncurses package also has many useful extensions over SVr4:

Applications using ncurses

The ncurses distribution includes a selection of test programs (including a few games). These are available separately as ncurses-examples

The ncurses library has been tested with a wide variety of applications including:

aptitude

FrontEnd to Apt, the debian package manager

https://wiki.debian.org/Aptitude

cdk

Curses Development Kit

https://invisible-island.net/cdk/

ded

directory-editor

https://invisible-island.net/ded/

dialog

the underlying application used in Slackware's setup, and the basis for similar install/configure applications on many systems.

https://invisible-island.net/dialog/

lynx

the text WWW browser

https://lynx.invisible-island.net/

mutt

mail utility

http://www.mutt.org/

ncftp

file-transfer utility

https://www.ncftp.com/

nvi

New vi uses ncurses.

https://sites.google.com/a/bostic.com/keithbostic/vi

ranger

A console file manager with VI key bindings in Python.

https://ranger.github.io/

tin

newsreader, supporting color, MIME

http://www.tin.org/

vifm

File manager with vi like keybindings

https://vifm.info/

as well as some that use ncurses for the terminfo support alone:

minicom

terminal emulator for serial modem connections

https://alioth.debian.org/projects/minicom/

mosh

a replacement for ssh.

https://mosh.org/

tack

terminfo action checker

https://invisible-island.net/ncurses/tack.html

tmux

terminal multiplexor

https://github.com/tmux/tmux/wiki

vile

vi-like-emacs may be built to use the terminfo, termcap or curses interfaces.

https://invisible-island.net/vile/

and finally, those which use only the termcap interface:

emacs

text editor

https://www.gnu.org/software/emacs/

less

The most commonly used pager (a program that displays text files).

http://www.greenwoodsoftware.com/less/

screen

terminal multiplexor

https://www.gnu.org/software/screen/

vim

text editor

https://www.vim.org/

Development activities

Zeyd Ben-Halim started ncurses 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 development work is done by Thomas E. Dickey. Thomas E. Dickey has acted as the maintainer for the Free Software Foundation, which held a copyright on ncurses for releases 4.2 through 6.1. Following the release of ncurses 6.1, effective as of release 6.2, copyright for ncurses reverted to Thomas E. Dickey (see the ncurses FAQ for additional information).

Contact the current maintainers at

bug-ncurses@gnu.org

To join the ncurses mailing list, please write email to

bug-ncurses-request@gnu.org
containing the line:

subscribe <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.invisible-island.net/ncurses/current/ and
https://invisible-mirror.net/archives/ncurses/current/ .

Patches to the current release are made available at

ftp://ftp.invisible-island.net/ncurses/6.2/ and
https://invisible-mirror.net/archives/ncurses/6.2/ .

There is an archive of the mailing list here:

http://lists.gnu.org/archive/html/bug-ncurses (also https)

Related resources

The release notes make scattered references to these pages, which may be interesting by themselves:

Other resources

The distribution provides a newer version of the terminfo-format terminal description file once maintained by Eric Raymond . Unlike the older version, the termcap and terminfo data are provided in the same file, which also provides several user-definable extensions beyond the X/Open specification.

You can find lots of information on terminal-related topics not covered in the terminfo file at Richard Shuford's archive . The collection of computer manuals at bitsavers.org has also been useful.