Fwd: [Hangout - NYLXS] ncurses 6.2
Joel Sherrill
joel at rtems.org
Sun Feb 16 21:01:55 UTC 2020
New ncurses release. RSB should need updating
---------- Forwarded message ---------
From: Thomas Dickey <dickey at his.com>
Date: Sun, Feb 16, 2020, 2:35 PM
Subject: [Hangout - NYLXS] ncurses 6.2
To: <info-gnu at gnu.org>
Announcing ncurses 6.2
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:
* It is used in almost every system based on the Linux kernel (aside
from some embedded applications).
* It is used as the system curses library on OpenBSD, FreeBSD and
MacOS.
* It is used in environments such as Cygwin and MinGW. The first of
these was EMX on OS/2 Warp.
* It is used (though usually not as the system curses) on all of the
vendor unix systems, e.g., AIX, HP-UX, IRIX64, SCO, Solaris,
Tru64.
* It should work readily on any ANSI/POSIX-conforming unix.
The distribution includes the library and support utilities, including
* captoinfo, a termcap conversion tool
* clear, utility for clearing the screen
* infocmp, the terminfo decompiler
* tabs, set tabs on a terminal
* tic, the terminfo compiler
* toe, list (table of) terminfo entries
* tput, utility for retrieving terminal capabilities in shell
scripts
* tset, to initialize the terminal
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 6.2, released February 12, 2020.
This release is designed to be source-compatible with ncurses 5.0
through 6.1; 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 user-defined
capabilities in terminal descriptions. The release notes also mention
some other bug-fixes, but are focused on new features and improvements
to existing features since ncurses 6.1 release.
Library improvements
New features
There are several new features:
* O_EDGE_INSERT_STAY tells the form library to optionally delay
cursor movement on a field edge/boundary
* O_INPUT_FIELD extension to form library allows a dynamic field to
shrink if the new limit is smaller than the current field size.
* added exit_curses and exit_terminfo to replace internal symbols
for leak-checking.
* added curses_trace, to replace trace().
Additionally, to improve performance other changes (and extensions)
are provided in this release:
* mouse decoding now handles shift/control/alt logic when decoding
xterm's 1006 mode
* ncurses now defines a limit for wgetnstr, wgetn_wstr when length
is negative or "too large".
* reordered loop-limit checks in winsnstr in case the string has no
terminating null and only the number of characters is used.
* there is now no buffer-size limit when reading the $TERMCAP
variable.
* the $TERMCAP variable may be interpreted as a fallback to a
terminfo entry
* mvcur now decides whether to use hard-tabs, using xt, tbc and hts
as clues.
* extended colors are improved by modifying an internal call to
vid_puts to pass extended color pairs e.g., from tty_update.c and
lib_mvcur.c
* the initialization functions now avoid relying upon persistent
data for the result from getenv
* scrolling is improved:
+ a limit check in newline_forces_scroll handles the case where
the row is inside scroll-margins, but not at the end.
+ improved loop limits in _nc_scroll_window handle a case where
the scrolled data is a pad which is taller than the window.
Other improvements
These are revised features:
* used "const" in some prototypes rather than NCURSES_CONST where
X/Open Curses was updated to do this, e.g., wscanw, newterm, the
terminfo interface. Also use "const" for consistency in the
termcap interface, which was withdrawn by X/Open Curses in Issue 5
(2007). As of Issue 7, X/Open Curses still lacks "const" for
certain return values, e.g., keyname.
* modified wbkgd and wbkgrnd to improve compatibility with SVr4
curses, changing the way the window rendition is updated when the
background character is modified
* improved terminfo write/read by modifying the fourth item of the
extended header to denote the number of valid strings in the
extended string table (see term(5)).
* modified the initialization checks for mouse so that the
xterm+sm+1006 block will work with terminal descriptions not
mentioning xterm.
These were done to limit or ultimately deprecate features:
* deprecated safe-sprintf, since the vsnprintf function, which does
what was needed, was standardized long ago.
* marked vwprintw and vwscanw as deprecated; recommend using
vw_printw and vw_scanw, respectively.
* added deprecation warnings for internal functions called by older
versions of tack.
* removed unused _nc_import_termtype2 function.
These are improvements to existing features:
* check parameter of set_escdelay, return ERR if negative.
* check parameter of set_tabsize, return ERR if not greater than
zero
* correct a status-check in _nc_read_tic_entry() so that if reading
a hex/b64 $TERMINFO, and the $TERM does not match, fall-through to
the compiled-in search list.
* amend check for repeat_char to handle a case where setlocale() was
called after initscr
* move macro for is_linetouched inside NCURSES_NOMACROS ifndef.
* use _nc_copy_termtype2 rather than direct assignment in setupterm,
in case it is called repeatedly using fallback terminfo
descriptions
* improve workaround for Solaris wcwidth versus line-drawing
characters
* add checks in repair_subwindows to keep the current position and
scroll-margins inside the resized subwindow.
* correct a buffer-limit in write_entry.c for systems that use
caseless filenames.
* improved build-time utility report_offsets:
+ add categories, e.g., "w" for wide-character, "t" for threads
to make the report more readable. Reorganized the structures
reported to make the categories more apparent.
+ add NCURSES_GLOBALS and NCURSES_PRESCREEN to report to show
how similar the different libtinfo configurations are.
* modified some header files to ensure that those include necessary
files except for the previously-documented cases
* added some traces in initialization to show whether a fallback
entry is used.
* made minor optimization to reduce calls to _nc_reserve_pairs
These are corrections to existing features:
* fix a special case in PutAttrChar where a cell is marked as
alternate-character set, but the terminal does not actually
support the given graphic character. This would happen in an older
terminal such as vt52, which lacks most line-drawing capability.
* corrected flag for "seq" method of db 1.8.5 interface, needed by
toe on some of the BSDs.
* modify comparison in make_hash.c to correct a special case in
collision handling for Caps-hpux11
* add extended_slk_color{,_sp} symbols to the appropriate
package/*.{map,sym} files
* modify lib_setup to avoid calling pthread_self() without first
verifying that the address is valid, i.e., for weak symbols
* add a couple of broken-linker symbols to the list of versioned
symbols to help with link-time optimization versus weak symbols.
Program improvements
Several improvements were made to the utility programs:
clear
+ improved logic for clearing with the E3 extension, in case
the terminal scrolls content onto its saved-lines before
actually clearing the display, by clearing the saved-lines
after clearing the display
infocmp
+ omit filtering of "OTxx" names which are used for obsolete
capabilities, when the output is sorted by long-names. This
change helps when making a table of the short/long capability
names.
tic
+ added check for consistent alternate character set
capabilities.
+ added check for paired indn/rin.
+ added check for terminals with parm_dch vs parm_ich.
+ added check for the case where setf/setb are given using
different strings, but provide identical results to
setaf/setab.
+ corrected check for ich1.
+ changed a too-large terminal entry from a fatal error to a
warning.
toe
+ ignores any hex/b64 $TERMINFO value in the list of terminfo
databases.
tset
+ replace check in reset command for obsolete "pt" capability
using tbc and hts capabilities as clues
+ modify reset to allow for tabstops at intervals other than 8.
+ change reset's behavior for margins to simply clear
soft-margins if possible, rather than clearing and then
setting them according to the terminal's width.
tput
+ add "x" to getopt string so that "tput -x clear" works.
Several changes were made to the generated ncurses*config scripts and
the analogous ".pc" files to reduce differences between the
configurations they report:
* modified the ncurse*-config and pc-files to more closely match for
the -I and -l options.
* filtered out linker-specs from the --libs report.
* amended the ncurses*-config and pc-files to take into account the
rpath hack which differed between those files.
* modified generated ncurses*config and ncurses.pc, ncursesw.pc,
etc., to list helper libraries such as gpm for static linking.
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:
* improve recovery from error when reading command-character in
test/ncurses.c, showing the relevant error message and not exiting
on EINTR.
* improve tracemunch, by keeping track of TERMINAL* values, and if
tracing was first turned on after initialization, attempt to show
distinct screen, window and terminal names anyway.
* modify tracemunch to accept filename parameters in addition to use
as a pipe/filter.
* update tracemunch to work with perl 5.26.2, which changed the
rules for escaping regular expressions.
* add some checks in tracemunch for undefined variables.
* modify TurnOn/TurnOff macros (in lib_vidattr.c and lib_vid_attr.c)
to avoid expansion of "CUR" in trace.
There are other new demo/test programs and reusable examples:
color_content
Demonstrate the color_content and extended_color_content
functions.
demo_tabs
A simple demo of tabs in curses.
dump_window
A portable curses screen-dump, used to compare ncurses screen
contents with Solaris.
pair_content
Demonstrate the pair_content and extended_pair_content
functions.
report_hashing
Check hash-tables used for terminfo and termcap names.
parse_rgb
Sample implementation of the ncurses RGB extension from
user_caps.5, used in picsmap and savescreen programs.
A variety of improvements were made to existing programs, both new
features as well as options added to make the set of programs more
consistent.
* add "-l" option to test/background, to dump screen contents in a
form that lets different curses implementations be compared.
* add "@" command to test/ncurses F-test, to allow rapid jump to
different character pages.
* added enum, regex examples to test/demo_forms
* amend Scaled256() macro in test/picsmap.c to cover the full range
0..1000
* corrected pathname used in Ada95 sample programs for explain.txt,
to work with test-packages, and used an awk script to split the
resulting pathname when it would be too long for a single line.
* ignore interrupted system-call in test/ncurses's command-line,
e.g., if the terminal were resized.
* improved ifdef's for TABSIZE variable, to help with AIX/HPUX
ports.
Terminal database
There are several new terminal descriptions:
alacritty, domterm, kitty, mintty, mintty-direct, ms-terminal,
n7900, nsterm-build309, nsterm-direct, screen5, ti703, ti707,
ti703-w, ti707-w vscode, vscode-direct, xterm-mono, xterm.js
There are many changes to existing terminal descriptions. Some were
updates to several descriptions:
* use ansi+rep in a dozen places
* add rs1 to konsole, mlterm
* improve several flash capabilities with trailing mandatory delays
* drop ich1 from rxvt-basic, Eterm and mlterm to improve
compatibility with old non-curses programs
* add/use xterm+keypad in xterm-new
* use xterm+sl-twm for consistency, nine places
* improve xm example in xterm+x11mouse and xterm+sm_1006.
while others affected specific descriptions. These were retested, to
take into account changes by their developers:
terminator, st
while these are specific fixes based on reviewing documentation, user
reports, or warnings from tic:
adds200:
+ fix typo
gnome-256color
+ base entry on "gnome", not "vte", for consistency
interix
+ trim unnecessary setf/setb
linux-16color
+ accommodate Linux console driver incompatibility introduced
in early 2018
nsterm-256color:
+ add nsterm-build309 to replace nsterm-256color, assigning the
latter as an alias of nsterm, to make mouse work with
nsterm-256color
regent40:
+ renumber function-keys to match manual
regent60:
+ add cd (clr_eos)
+ corrected acsc
+ add shifted function-keys
tvi950:
+ added function-key definitions to agree with Televideo 950
manual
+ corrected acsc
+ remove bogus kf0
+ add bel
tvi955:
+ fix typo
vi200:
+ add acsc string, including right/down-arrow
wy50:
+ corrected acsc
wy50 and wy60:
+ add shifted function-keys as kF1 to kF16
xterm+x11hilite:
+ eliminate unused p5 parameter.
A few entries use extensions (user-defined terminal capabilities):
* use xterm+sm+1006 (aka "SGR 1006 mouse") for konsole-base and
putty
* add Smol/Rmol user-defined capability to tmux and vte-2018
* add Smulx user-defined capability to tmux, vte-2018
Documentation
As usual, this release
* improves documentation by describing new features,
* attempts to improve the description of features which users have
found confusing
* fills in overlooked descriptions of features which were described
in the NEWS file but treated sketchily in manual pages.
In addition to providing background information to explain these
features and show how they evolved, there are corrections,
clarifications, etc.:
* Corrections:
+ correct error-returns listed in manual pages for a few form
functions
+ corrected prototypes in several manpages using script to
extract those in compilable form.
+ fix typo in term.5, improve explanation of format
* Clarify in manual pages that vwprintw and vwscanw are obsolete.
They have not been part of X/Open Curses since 2007.
* New/improved history and portability sections:
+ curs_addch.3x gives some background for ACS symbols.
+ curs_getcchar.3x explains a difference between ncurses and
X/Open Curses.
+ curs_getstr.3x gives historical/portability background for
the length parameter of wgetnstr.
+ curs_slk.3x lists a few differences between SVr4 curses and
X/Open Curses for soft-keys.
+ curs_terminfo.3x explains that the initial implementation of
terminfo in SVr2 was mostly replaced by other developers in
SVr3.
+ infocmp.1 explains that the initial version of terminfo had
no tool for decompiling descriptions. That came later, with
SVr3, with a different developer.
+ tabs.1 tells more than you wanted to know about the tool.
+ tic.1 explains that the initial version of terminfo had a
rudimentary tool (based on termcap) for compiling entries.
The tool used with Unix was developed by others for SVr3.
+ toe.1 explains the origin of this tool.
* Improvements for user_caps.5:
+ mention meml, memu and box1
+ expanded description of XM
+ add a clarification regarding the RGB capability.
+ mention user_caps.5 in the tic and infocmp manual pages.
* Other improvements:
+ curs_add_wch.3x adds note about Unicode terminology for the
line-drawing characters.
+ curs_color.3x improves discussion of error returns and
extensions.
+ curs_mouse.3x explains how the kmous and XM capabilities are
used for xterm-mouse input.
+ curs_refresh.3x improves documentation regarding the virtual
and physical screens.
+ curs_util.3x mentions a difference between SVr4 and X/Open
Curses for unctrl.h
+ curs_variables.3x improves description of the init_tabs
capability and TABSIZE variable.
+ ncurses.3x improves documentation regarding feature-test
macros in curses.h
+ resizeterm.3x about top-level windows which touch the
screen's borders.
+ tput.1 clarifies how tput determines the terminal size.
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, the generated terminfo.5 file
uses a different table layout, allowing it to use space on wide
terminals more effectively.
Interesting bug-fixes
While there were many bugs fixed during development of ncurses 6.2,
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 in tic/infocmp's handling of user-defined
capabilities. These were not recent bugs. Initially it was a simple
problem:
* The user-defined capabilities can be any type (boolean, number or
string), but once given a type all uses of the name must conform
to that type--unless some special support for a particular
multi-typed name is built into ncurses.
* One of simpleterm's contributors copied some definitions for using
tmux's user-defined capabilities in late in 2016.
diff --git a/st.info b/st.info
@@ -185,7 +185,10 @@ st| simpleterm,
tsl=\E]0;,
xenl,
vpa=\E[%i%p1%dd,
-
+# Tmux unofficial extensions, see TERMINFO EXTENSIONS in tmux(1)
+ Se,
+ Ss,
+ Tc,
st-256color| simpleterm with 256 colors,
use=st,
* Later, in (referring to a version from mid-2017), a user asked to
have it updated in ncurses.
* However, it had an error from the change in late 2016. The
terminal description made what tmux expected to be string actually
a boolean.
Over the years, there were problems with each of simpleterm's
terminal descriptions. I repaired those, and usually dealt with
the problem.
* The difference in this case was that when compiling the terminal
database, tic may have in memory the definitions for more than one
terminal description (so that it can resolve "use=" clauses).
Seeing two different types for the same name, in certain
situations it would incorrectly merge the symbol tables for the
two terminal descriptions.
* On simpleterm's side, their bug was finally fixed in late 2019,
three years after the bug was created.
For ncurses, the elapsed time to fix this bug was less than three
years. Someone reported a problem with the terminal description a few
weeks after releasing ncurses 6.1 (in tmux #1264), and the terminal
description was updated that week (ncurses patch 20180224):
20180224
+ modify _nc_resolve_uses2() to detect incompatible types when
merging
a "use=" clause of extended capabilities. The problem was seen
in a
defective terminfo integrated from simpleterm sources in 20171111,
compounded by repair in 20180121.
+ correct Ss/Ms interchange in st-0.7 entry (tmux #1264) -TD
The larger part of that change added a check to prevent a simple merge
of terminal descriptions where the same user-defined name was used
with different types. But it raised some questions:
* Was there a reliable way to manage terminal descriptions which
used the same extended name in different ways?
* Should ncurses provide a registry of well-known extended names,
with their types?
Since the correction to terminfo.src could have been readily adopted
by packagers, there was nothing more to be done from ncurses'
standpoint on that part. But improving ncurses to prevent issues like
that is the reason for making a release.
Nothing more (constructive) was mentioned with regard to simpleterm.
But a few problems were found in the handling of user-defined
capabilities:
* Forward-references to user-defined capabilities in a "use=" clause
did not allocate new data for each use. In tic, successive
compilation of terminal entries could add user-defined
capabilities to the wrong terminal entry.
This was not noticed before, since xterm's terminal descriptions
were the main users of the feature, and almost all of the uses of
the building-blocks which contained user-defined capabilities were
backward-references.
* There is one (documented) case where ncurses 6.1 supports a
user-defined capability that could be any type (i.e., "RGB"). The
check added in February 2018 to guard against mismatches did not
handle all of the combinations needed.
Both of these issues dated from the original implementation of
user-defined capabilities. Fixing them does not change the terminal
database, but a older tic without the fixes will not be able to handle
terminfo sources which rely upon those fixes. Starting in June 2019,
the download link for the terminfo source file was capped at that
date. The development sources have an up-to-date copy of the file, for
people with a legitimate need for it.
The "-c" (check) option of tic is not very useful if it cannot offer
advice on parameters needed for user-defined capabilities. The various
Caps files were reorganized to reduce redundancy, and in the common
portion (Caps-ncurses), a registry of user-defined capabilities is
provided for use by tic. While users can still define their own custom
capabilities, tic will not offer any advice when their parameters do
not match.
In ncurses 6.2, tic makes a special check to allow any type for RGB,
but its being able to do this relies upon fixes made in the ncurses
library in mid-2019.
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:
--with-config-suffix
helps work around a filename conflict with Debian packages
versus test-packages.
--with-ada-libname
allows one to rename the "AdaCurses" library (at least one
packager prefers a lowercase name).
--with-fallbacks
now ensures there is a value, and adds the fallback information
to top-level Makefile summary.
--with-pcre2
check for pcre-posix library to help with MinGW port.
--with-tic-path and
--with-infocmp-path
help work around problems building fallback source using
pre-6.0 tic/infocmp.
--with-versioned-syms
option value can now be a relative pathname.
Portability
Many of the portability changes are implemented via the configure
script:
* ignore $TERMINFO as a default value in configure script if it came
from the infocmp -Q option.
* distinguish gcc from icc and clang when the --enable-warnings
option is not used, to avoid unnecessary warnings about
unrecognized inline options
* consistently prepend new libraries as they are found during
configuration, rather than relying upon the linker to resolve
order dependencies of libraries.
* modified configure scripts to reduce relinking/ranlib during
library install :
+ use "install -p" when available, to avoid need for ranlib of
static libraries.
+ scripts which use "--disable-relink;" add a 1-second sleep to
work around tools which use whole-second timestamps, e.g., in
utime rather than the actual file system resolution.
* add configure check for getenv to work around implementation shown
in Emscripten which overwrites the previous return value on each
call.
Use that to optionally suppress START_TRACE macro, whose call to
getenv may not work properly
* change target configure level for _XOPEN_SOURCE to 600 to address
use of vsscanf and setenv.
* reduce use of _GNU_SOURCE for current glibc where _DEFAULT_SOURCE
combines with _XOPEN_SOURCE
Allow for Cygwin's newlib when checking for the _DEFAULT_SOURCE
symbol.
MidnightBSD is now checked for the _XOPEN_SOURCE-related
definitions.
* If the check for va_copy or __va_copy fails,
+ configure now tries copying the pointers for va_list, or as
an array.
+ alternatively, it checks for __builtin_va_copy(), which could
be used with AIX xlc in c89 mode.
* several changes to support a port to Ultrix 3.1:
+ check if "b" binary feature of fopen works
+ check for missing feature of locale.h
+ add fallback for strstr() in test-programs
+ add fallback for STDOUT_FILENO in test-programs
* The test/configure script (used for ncurses-examples) is improved:
+ work around non-ncurses termcap.h file, e.g., in Slackware.
+ check for TABSIZE variable.
+ checks for the X11/Intrinsic.h header, accommodate recent
MacOS changes which largely emptied /usr/include.
Here are some of the other portability fixes:
* added dummy "check" rule in top-level and test-Makefile to
simplify building test-packages for ArchLinux.
* dropped library-dependency on psapi for MinGW port, since
win_driver.c defines PSAPI_VERSION to 2, making it use
GetProcessImageFileName from kernel32.dll
* made build-fixes for configuration using --program-suffix with
Ada95, noticed with MacOS but applicable to other platforms
without libpanelw, etc.
* modified ncurses/Makefile.in to fix a case where Debian/testing
changes to the ld --as-needed configuration broke ncurses-examples
test packages.
* used _WIN32/_WIN64 in preference to __MINGW32__/__MINGW64__
symbols to simplify building with Microsoft Visual C++, since the
former are defined in both compiler configurations.
_________________________________________________________________
Features of ncurses
The ncurses package is fully upward-compatible with SVr4 (System V
Release 4) curses:
* All of the SVr4 calls have been implemented (and are documented).
* ncurses supports all of the for SVr4 curses features including
keyboard mapping, color, forms-drawing with ACS characters, and
automatic recognition of keypad and function keys.
* ncurses provides these SVr4 add-on libraries (not part of X/Open
Curses):
+ the panels library, supporting a stack of windows with
backing store.
+ the menus library, supporting a uniform but flexible
interface for menu programming.
+ the form library, supporting data collection through
on-screen forms.
* ncurses's terminal database is fully compatible with that used by
SVr4 curses.
+ ncurses supports user-defined capabilities which it can see,
but which are hidden from SVr4 curses applications using the
same terminal database.
+ It can be optionally configured to match the format used in
related systems such as AIX and Tru64.
+ Alternatively, ncurses can be configured to use hashed
databases rather than the directory of files used by SVr4
curses.
* The ncurses 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, and most EXTENDED features). It includes 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 FreeBSD
and OS/2 console windows.
* Extended mouse support via Alessandro Rubini's gpm package.
* 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 keyok and 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
code.
* Support for 256-color terminals, such as modern xterm.
* Support for 16-color terminals, such as aixterm and modern xterm.
* 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/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 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.
* 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.
* Extensive documentation is provided (see the Additional Reading
section of the ncurses FAQ for online documentation).
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.mit.edu/
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.
Juergen 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
holds 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 at gnu.org
To join the ncurses mailing list, please write email to
bug-ncurses-request at 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/6.1/ and
https://invisible-mirror.net/archives/ncurses/6.1/ .
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:
* ncurses licensing
* Symbol versioning in ncurses
* Comments on ncurses versus slang (S-Lang)
* tack - terminfo action checker
* tctest - termcap library checker
* Terminal Database
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.
* Overview
* Release Notes
+ Library improvements
o New features
o Other improvements
+ Program improvements
o Utilities
o Examples
+ Terminal database
+ Documentation
+ Interesting bug-fixes
+ Configuration changes
o Major changes
o Configuration options
+ Portability
* Features of ncurses
* Applications using ncurses
* Development activities
* Related resources
* Other resources
--
Thomas E. Dickey <dickey at invisible-island.net>
https://invisible-island.net
ftp://ftp.invisible-island.net
--
If you have a working or partly working program that you'd like
to offer to the GNU project as a GNU package,
see https://www.gnu.org/help/evaluation.html
._______________________________________________
Hangout mailing list
Hangout at nylxs.com
http://lists.mrbrklyn.com/mailman/listinfo/hangout
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