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
These notes are for ncurses 6.1, released January 27, 2018.
This release is designed to be source-compatible with ncurses 5.0 through 6.0; providing extensions to the application binary interface (ABI). Although the source can still be configured to support the ncurses 5 ABI, the intent of the release is to provide extensions to the ncurses 6 ABI:
improve integration of tput and tset
provide support for extended numeric capabilities.
There are, of course, numerous other improvements, listed in this announcement.
The release notes also mention some bug-fixes, but are focused on new features and improvements to existing features since ncurses 6.0 release.
The improved integration of tput and tset made only small changes to the libraries. However, supporting extended numeric capabilities required a few changes:
The TERMINAL structure in
<term.h> is now opaque. Doing that allowed
making the structure larger, to hold the extended numeric
data.
A few applications required changes during development of ncurses 6.1 because those applications misused the members of that structure, e.g., directly modifying it rather than using def_prog_mode.
Having made TERMINAL opaque (and because none
of the library functions use anything except a pointer to
TERMINAL), it was possible to increase the size
of the structure, adding to the end.
Existing applications which were linked to the
ncurses 6.0 high-level
(ncurses, ncursesw) and low-level
(tinfo, tinfo) libraries should not require
re-linking since the binary interface did not change, nor did
the structure offsets with TERMINAL change.
A few applications use the inner TERMTYPE
structure's offsets to refer to terminfo capabilities within
that structure. Again, those do not require modification
because their offsets within TERMINAL did not
change.
When configured for wide-characters, i.e.,
“ncursesw” the TERMINAL structure is
extended.
The new data in TERMINAL holds the same
information as TERMTYPE, but with larger numbers
(“int” versus “short”). It is named
TERMTYPE2.
The library uses this structure internally in preference
to TERMTYPE, referring to TERMTYPE
only to initialize it for applications that use the
capabilities defined in <term.h>
When configured for 8-bit (narrow) characters, the
TERMTYPE2 structure is not used.
The motivation for making this extension came from noticing that termcap applications could (though not realistically) use larger numbers than would fit in 16-bits, and the fact that the number of color pairs for a 256-color xterm could not be expressed in terminfo (i.e., 32767 versus 65536). Also, a few terminals support direct-colors, which could use the extension.
Generally speaking, applications that use internal details of
a library are unsupported. There was exactly one exception for
ncurses: the tack program used the internal
details of TERMINAL, because it provides an
ncurses-specific feature for interactively modifying a terminfo
description and writing the updated description to a text-file.
It was possible to not only separate tack from these internal
details of ncurses, but to
generalize it so that the program works with Unix curses
(omitting the ncurses-specific feature). That was released as
tack 1.08 in July
2017.
While making changes to tack to eliminate its dependency upon ncurses internals, the publicly-visible details of those internals were reviewed, and some symbols were moved to private header files, while others were marked explicitly as ncurses internals. Future releases of ncurses may eliminate some of those symbols (such as those used by tack 1.07) because they are neither part of the API or the ABI.
Using the TERMTYPE2 extended numeric
capabilities, it is possible to support both color pair values
and color values past 32767. Taking compatibility into account,
developers readily understand that neither function signatures
nor structure offsets change. Also, existing functions have to
operate with the extended numbers. Most of that work is internal
to the library. For the external interfaces, a hybrid approach
was used:
X/Open Curses defined function prototypes such as
wattr_set with an unused parameter, for
“future” use. After 25 years, the future is here:
ncurses uses the parameter to
augment color pair values as described in the
manual page.
Other functions such as those defining color pairs did not
have a corresponding reserved parameter. For those,
ncurses defines extended
versions such as init_extended_pair (versus
init_pair), init_extended_color
(versus init_color).
Additionally, to improve performance other changes (and extensions) are provided in this release:
Several new functions simplify management of large sets of
color pairs: reset_color_pairs,
alloc_pair, find_pair and
free_pair.
New "RGB" extension capability for direct-color support is
used to improve performance of
color_content.
The internal colorpair_t is now a struct,
eliminating an internal 8-bit limit on colors
Allocation for SCREEN's color-pair table
starts small, grows on demand up to the limit given in the
terminal description.
setcchar and getcchar now treat
a negative color-pair as an error.
These are new or revised features:
modify c++/etip.h.in to accommodate
deprecation of throw and throws in c++17
add new function unfocus_current_field
add option to preserve leading whitespace in form fields
add a macro for is_linetouched and adjust the
function's return value to make it possible for most
applications to check for an error-return.
add build-time utility report_offsets to help
show when the various configurations of tinfo library are
compatible or not.
These were done to limit or ultimately deprecate features:
drop two symbols obsoleted in 2004:
_nc_check_termtype, and
_nc_resolve_uses
move _nc_tracebits, _tracedump
and _tracemouse to curses.priv.h,
since they are not part of the suggested ABI6.
mark some structs in form/menu/panel libraries as potentially opaque without modifying API/ABI.
ifdef'd header-file definition of mouse_trafo
with NCURSES_NOMACROS
remove initialization-check for calling napms
in the term-driver configuration; none is needed.
modify trace to avoid overwriting existing
file
These are improvements to existing features:
modify make_hash to allow building with
address-sanitizer, assuming that --disable-leaks
is configured.
move SCREEN field for use_tioctl
data before the ncursesw fields, and limit that to the
sp-funcs configuration to improve termlib compatibility
modify db-iterator:
ignore zero-length files in db-iterator; these are
useful for instance to suppress
$HOME/.terminfo when not wanted.
modify update_getenv to ensure that
environment variables which are not initially set will be
checked later if an application happens to set them
modify _nc_outc_wrapper to use the standard
output if the screen was not initialized, rather than
returning an error.
improve checks for low-level terminfo functions when the terminal has not been initialized.
modify set_curterm to update
ttytype[] data used by longname/p>
modify _nc_get_screensize to allow for
use_env and use_tioctl state to be
per-screen when sp-funcs are configured, better matching the
behavior when using the term-driver configuration.
remove an early-return from _nc_do_color,
which can interfere with data needed by bkgd
when ncurses is configured
with extended colors
incorporate A_COLOR mask into
COLOR_PAIR, in case user application provides an
out-of-range pair number
modify logic for endwin-state to be able to
detect the case where the screen was never initialized, using
that to trigger a flush of ncurses' buffer for mvcur,
e.g., in the sample program dots_mvcur for the term-driver
configuration.
These are corrections to existing features:
fixes for writing extended color pairs in
putwin.
modify no-leaks code for lib_cur_term.c to
account for the tgetent cache.
amend handling of the repeat_char capability
in EmitRange to avoid scope creep: translate the
character to the alternate character set when the alternate
character set is enabled, and do not use
repeat_char for characters past 255.
improve wide-character implementation of
myADDNSTR in frm_driver.c, which
was inconsistent with the normal implementation.
modify winnstr and winchnstr to
return error if the output pointer is null, as well as adding
a null pointer check of the window pointer for better
compatibility with other implementations.
modify setupterm to save original tty-modes
so that erasechar works as expected. Also modify
_nc_setupscreen to avoid redundant calls to get
original tty-modes.
modify wattr_set and wattr_get
to return ERR if win-parameter is null,
as documented.
correct order of initialization for traces in
use_env and use_tioctl versus first
_tracef calls.
correct parameters for copywin call in
_nc_Synchronize_Attributes
flush the standard output in _nc_flush for
the case where SP is zero, e.g., when called via
putp. This fixes a scenario where
“tput flash” did not work after changes in
20130112.
amend internal use of tputs to consistently
use the number of lines affected, e.g., for insert/delete
character operations. While merging terminfo source early in
1995, several descriptions used the
“*” proportional delay for these
operations, prompting a change in doupdate.
correct return-value of extended putwin.
double-width multibyte characters were not counted
properly in winsnstr and
wins_nwstr.
amend fix for _nc_ripoffline from 20091031 to
make test/ditto.c work in threaded
configuration.
modify _nc_viscbuf2 and
_tracecchar_t2 to trace wide-characters as a
whole rather than their multibyte equivalents.
minor fix in wadd_wchnstr to ensure that each
cell has nonzero width.
move PUTC_INIT calls next to
wcrtomb calls, to avoid carry-over of error
status when processing Unicode values which are not
mapped.
add missing assignment in lib_getch.c to make
notimeout work
While reviewing user feedback, it became apparent that the differences between reset (an alias for tset) and “tput reset” were confusing:
On further investigation, it turned out that the differences were largely an accident due to the way those programs had evolved.
This release eliminates the unnecessary differences, using the same approach for tput's init (initialization), reset and clear operations as the separate reset and clear programs. Doing this does not change the command-line options; existing scripts are unaffected.
These are the user-visible changes for the three programs (tput, tset and clear):
add the terminal-mode parts of “reset” (aka tset) to the “tput
reset” command, making the two almost the same
except for window-size.
improve tput's check for being called as “init” or “reset” to allow for transformed names.
add “clear” as a possible link/alias to tput.
amend changes for tput to reset tty modes to “sane” if the program is run as “reset”, like tset. Likewise, ensure that tset sends either reset- or init-strings.
add -x option to clear/tput
to make the E3 extension optional
add functionality of
“tset -w” to tput, like the
“-c” feature this is not optional in
tput.
add options -T and -V to
clear command for
compatibility with tput.
drop long-obsolete “-n” option
from tset.
modify tset's assignment to
TERM in its output to reflect the name by which
the terminal description is found, rather than the primary
name. That was an unnecessary part from the initial
conversion of tset from
termcap to terminfo. The termcap library in 4.3BSD did this
to avoid using the short 2-character name
remove a restriction in tput's support for termcap names which omitted capabilities normally not shown in termcap translations
add usage message to clear command
improve usage messages for tset and tput.
Other user-visible improvements and new features include:
modify tic/infocmp display of numeric values to use hexadecimal when they are "close" to a power of two, making the result more readable.
add “-W” option to tic/infocmp
to force long strings to wrap.
This is in addition to the
“-w” option which attempts to
fit capabilities into a given line-length.
If “-f” option splits line,
do not further split it with
“-W”.
Begin a new line when adding
“use=” after a wrapped line.
add “-q” option to infocmp to suppress the
“Reconstructed from” comment from
the header, and a corresponding option to tic to suppress all comments from the
“tic -I” output.
Sorted options in usage message for infocmp, to make it simpler to see unused letters.
Updated usage message for tic, adding “-0”
option.
add infocmp/tic “-Q” option,
which allows one to dump the compiled form of the terminal
entry, in hexadecimal or base64:
b64:” prefix in the
TERMINFO variable tells the terminfo reader to
use base64 according to RFC-3548 as well as RFC-4648
url/filename-safe format.hex:” prefix tells the
terminfo reader to accept hexadecimal data as generated by
“infocmp -0qQ1”.Other less-visible improvements and new features include:
modify utility headers such as tic.h to make
it clearer which are externals that are used by tack.
add “reset” to list of programs
whose names might change in manpages due to
program-transformation configure options.
modify “-T” option of
clear and tput to call use_tioctl to
obtain the operating system's notion of the screensize if
possible.
add check in tput for init/reset operands to ensure those use a terminal.
modify programs clear, tabs, tput and tset to pass the actual tty file descriptor to setupterm rather than the standard output or error, making padding work.
change tset's
initialization to allow it to get settings from the standard
input as well as /dev/tty, to be more effective
when output or error are redirected.
amend check in tput,
tabs and clear to allow those to use the
database-only features in cron
if a “-T” option gives a suitable
terminal name.
improve error message from tset/reset when both stderr/stdout are redirected to a file or pipe.
Several of the less apparent features deal with translation of terminfo to termcap (and the reverse), with corresponding checks by tic:
modify check in fmt_entry to handle a
cancelled reset string. Make similar fixes in other parts of
dump_entry.c and tput.c
correct read of terminfo entry in which all strings are absent or explicitly cancelled. Before this fix, the result was that all were treated as only absent.
modify infocmp to suppress
mixture of absent/cancelled capabilities that would only show
as “NULL, NULL”, unless the
“-q” option is used, e.g., to show
“-, @” or “@,
-”.
correct a warning from tic about keys which are the same, to skip over missing/cancelled values.
add check in tic for use of
bold, etc., video attributes in the color capabilities,
accounting whether the feature is listed in
ncv.
add check in tic for
unnecessary use of “2” to denote a
shifted special key.
improve check in tic for delays by also warning about beep/flash when a delay is not embedded, or if those use the VT100 reverse video escape without using a delay.
improve checks in trim_sgr0, comp_parse.c and
parse_entry.c, for cancelled string capabilities.
add check in tic for some syntax errors of delays, as well as use of proportional delays for non-line capabilities.
add check in tic for
conflict between ritm, rmso,
rmul versus sgr0.
add check in _nc_parse_entry for invalid
entry name, setting the name to
“invalid” to avoid problems storing
entries.
improve _nc_tparm_analyze, using that to
extend the checks made by tic
for reporting inconsistencies between the expected number of
parameters for a capability and the actual.
remove tic warning about
“^?” in string capabilities, which
was marked as an extension; however all Unix implementations
support this and X/Open Curses does not address it. On the
other hand,
BSD termcap did not support this feature (until the
mid-1990s).
in _nc_infotocap, added a check to ensure
that terminfo “^?” is not written to
termcap.
modify sscanf calls in
_nc_infotocap for patterns
“%{number}%+%c” and
“%'char'%+%c” to check that the
final character is really “c”,
avoiding a case in icl6404 which cannot be converted to
termcap.
in _nc_tic_expand and
_nc_infotocap, improved string-length check when
deciding whether to use “^X” or
“\xxx” format for control
characters, to make the output of tic/infocmp
more predictable.
limited termcap “%d” width to 2
digits on input, and use “%2” in
preference to “%02” on output.
correct terminfo/termcap conversion of
“%02” and
“%03” into
“%2” and
“%3”; the result repeated the last
character.
Along with the library and utilities, many improvements were made to the ncurses-examples.
These changes were made to demonstrate new extensions in ncurses:
add demo_new_pair program,
to demonstrate
alloc_pair,
find_pair and
free_pair functions.
This program iterates over the possible color combinations, allocating or initializing color pairs. For best results, choose screen-width dividing evenly into the number of colors. e.g.,
32x64,32x128256 colors 24x44,24x8888 colors 32x64,24x12816 colors
add extended_color program, like the older color_set program, but using the extended color functions, with and without the SP-functions interface.
add picsmap program to fill in some testing issues not met by dots, using this as the third example in a comparison of the ncurses versus slang libraries.
The program can directly read X bitmap and pixmap files, displaying a picture. It can read other image files using ImageMagick's convert program to translate the image into text.
For 16-, 88- and 256-color terminal descriptions,
picsmap can load a palette
file which tells it which color palette entries to use. For
direct-colors, the terminal descriptions use the
RGB extension capability.
There are other new example programs and a few scripts:
add dots_xcurses program to illustrate a different approach used for extended colors which can be contrasted with dots_curses.
add list_keys program show function keys for one or more terminal descriptions. It uses ncurses's convention of modifiers for special keys, based on xterm.
add padview program, to compare pads with direct updates in the view program.
add sp_tinfo program to exercise the SP-functions extension of the low-level terminfo library.
add test-programs for termattrs and
term_attrs functions.
add test_sgr program to exercise all combinations of the sgr capability.
add tput-colorcube demo script, imitating xterm's 88- and 256-color scripts using tput.
add tput-initc script to demonstrate how tput may be used to initialize a color palette from a data file.
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.
The ncurses program is the largest; a proportionately large number of changes were made to it:
modify a/A screens to make exiting on an escape character depend on the start of keypad and timeout modes, to allow better testing of function-keys.
add “t” toggle for
notimeout function.
modify layout of b/B screens to allow for additional annotation on the right margin; some terminals with partial support did not display well.
modify c/C screens to allow for extended color pairs.
add z/Z zoom feature to make extended color pairs easier to test.
modify test-screens to take advantage of wide screens, reducing the number of lines used for 88- and 256-colors.
modify “d” edit-color screen to
optionally read xterm color palette directly from terminal,
as well as handling KEY_RESIZE and
screen-repainting with control/L and control/R.
add examples to “F” screen for
WACS_D_PLUS and WACS_T_PLUS.
improve “g” screen, correcting
ifdef which made the legend not reflect changes to keypad-
and scroll-modes. Added check for return-value of
putwin.
make “s” test easier to
understand which subtests are available
add a corresponding “S”
wide-character overlap test-screen.
add “v” screen to show
baudrate and other values.
These changes were made to the other examples:
modify blue program to use Unicode values for card-glyphs when available, as well as improving the check for CP437 and CP850.
improve demo_menus program,
allowing mouse-click on the menu-headers to switch the active
menu. This requires a new extension option
O_MOUSE_MENU to tell the menu driver to put
mouse events which do not apply to the active menu back into
the queue so that the application can handle the event.
correct logic in demo_terminfo program for
“-f” option
modify ditto program to
allow $XTERM_PROG environment variable to
override "xterm" as the name of the program to run in the
threaded configuration.
add several options to the “dots” test-programs.
modify filter program:
getnstr, that
polls for input while updating a clock on the right margin
as well as responding to window size-changes.--keep-tite” option for
filter program as the "-a"
option. When set, filter
attempts to suppress the alternate screen.modify knight program to
provide the "slow" solution for small screens using
“R”, noting that Warnsdorf's method
is easily done with “a”.
modify the savescreen program to add test patterns that exercise 88-, 256-, etc., colors.
add options to test_arrays, for selecting termcap vs terminfo, etc.
modify the view program:
-n” option by
simply reading the whole file.SIGWINCH example; just
use KEY_RESIZE.improve animation in xmas
program by adding a time-delay in blinkit.
modify several test-programs which call
use_default_colors to consistently do this only
if the “-d” option is given.
modify the install-rule for ncurses-examples to put the
data files in the data directory, e.g.,
/usr/share/ncurses-examples.
modify several test programs to use new
popup_msgs function, adapted from the
help-screen used in the edit_field program.
modify test data for xterm palettes to use the newer color4/color12 values.
improve the tracemunch script:
add_wch,
color_content and pair_content to
dummy parameters.There are several new terminal descriptions:
dumb-emacs-ansi,dvtm,dvtm-256color,fbterm,iterm2,linux-m1minitel entries,putty-noapp,viewdata, andvt100+4bsdbuilding-block.
xterm+noalt,xterm+titlestack,xterm+alt1049,xterm+alt+titlebuilding blocks andxterm+direct,xterm+indirect,xterm-direct. from xterm patch #331.several other “
-direct” descriptions to address the differences of other terminal emulators versusxterm-direct.
There are many changes to existing terminal descriptions. Some were updates to several descriptions:
xterm+sm+1006 in several terminal
descriptions which were validated as supporting the extended
mouse feature for their respective terminal emulators.while others affected specific descriptions. These were retested, to take into account new/undocumented changes by their developers:
iterm,minitel,st,viewdata,nsterm
while these are specific fixes based on user reports, or warnings from tic:
ansi building blocksansi+idc to better match original
ansiterm+idc, add alias
ansitermicl6402icl6402 and
m2-naminterix^? for kdch1linuxlinux3.0 entry the default
linux entrylinux2.6 entry to improve
line-drawing so that the linux3.0 entry can be
used in non-UTF-8 modelinux
and wyse entries to put the delay between the
reverse/normal escapes rather than afterlinux-16color to not mask dim,
standout or reverse with the ncv capabilitypccon entriespccon* entriespccon+sgr+acs and
pccon-basepccon+keystmuxscreen's "standout" code rather than the
standard code.xterm-keys
option to reflect upcoming change to make that option
"on" by defaultvt100vt100 rs2 string to reset
vt52 mode and scrolling regionsvt100-namvt100+4bsd, e.g.,
delay in sgr for consistencyvtevte-2014 to
vte-2012xtermxterm-new, available
since
late 1996.xterm+256color and
xterm+256setaf to use correct number of color
pairs.xterm-16color,
xterm-88color and xterm-256color
to reset palette using oc string as in
linux entry.xterm-256colorxterm+256color, allowing palette reset for
xtermxterm+256setafxterm-r5, xterm-r6 and
xterm-xf86-v32 to use xterm+kbs
to match
xterm #272, reflecting packager's changesxterm-new, to reflect vt220-style responses
that could be returned.xterm-pcolor sgr consistent
with other capabilitiesA few entries use extensions (user-defined terminal capabilities):
tmux and xterm-basicAs 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 particular,
Since the underlying features for tset, tput, and clear have been better integrated, the documentation now includes information on how those tools evolved.
In addition to explaining the improved integration of the tools, the manual pages made it easier to see how the tools are similar and how they are different.
The addch manual page has additional
information on
portability and differences from other
implementations.
The discussion of color-pairs in the attributes manual page is improved in its history section.
The documentation of the chtype,
cchar_t types and the attribute values which can
be stored in those types, in particular the
history and
portability sections of the attributes manual
page, has been improved.
improve discussion of portability in the mouse manual.
The pad manual page has a section on the origin and portability of pads.
Differences between SVr4 and X/Open Curses soft-keys are discussed in a new section on portability.
There are updated/improved notes on portability in the resizeterm and wresize manual pages.
In addition to providing background information to explain these features and show how they evolved, there are corrections, clarifications, etc.:
add note in the addch manual about line-drawing when it depends upon UTF-8.
improve discussion of line-drawing characters in the add_wch manual.
explain in clear's manual page that it writes to the standard output.
improve description of endwin.
improve discussion of field validation in the form driver manual page.
clarify the use of wint_t vs
wchar_t in
get_wstr manual page.
clarify in the
getch manual that the keypad mode affects an
application's ability to read KEY_MOUSE codes,
but does not affect KEY_RESIZE.
trim some obsolete/incorrect wording about
EINTR from the getch manual page
improve manual pages for
getch and
get_wch to point out that they might return
user-defined values which have no predefined names in
<curses.h>
improve description of the -R option in the
infocmp manual page
clarify in the
resizeterm manual page how
KEY_RESIZE is pushed onto the input stream.
document return value of
use_extended_names
document differences in
ESCDELAY versus AIX's implementation in the
variables manual page.
The _nc_free_tinfo function is now documented
in the
memory-leaks manual page, because it could be
used in tack for memory-leak
checking.
add a note to the tic manual page about -W versus -f options.
improve terminfo manual description of terminfo syntax.
improve terminfo manual page discussion of control- and graphics- characters.
improve color-handling section in terminfo manual page
clarify description in tput manual page regarding support for termcap names
update tput manual page to reflect changes to manipulate terminal modes by sharing functions with tset.
clarify in manual pages that the optional verbose option level of tic and infocmp is available only when ncurses is configured for tracing.
improve manual page description of tset/reset versus window-size.
improve description of tgoto parameters
There are new manual pages:
scr_dump documents the screen-dump format.
Some of the improvements are more subtle, relating to the way the information is presented:
Made minor fixes to manpage NAME/SYNOPSIS sections to consistently use rule that either all functions which are prototyped in SYNOPSIS are listed in the NAME section, or the manual-page name is the sole item listed in the NAME section. The latter is used to reduce clutter, e.g., for the top-level library manual pages as well as for certain feature-pages such as SP-funcs and threading.
improve manual pages for utilities with respect to POSIX versus X/Open Curses.
improve organization of the attributes and color manual pages.
modify toe to not exit if unable to read a terminal description, e.g., if there is a permission problem.
correct 20100515 change for weak signals versus sigprocmask
gprconfig to specify the C compiler to be
used by gnatmake, and conditionally suppressing
Library_Options line for static libraries.There were, as well, several bug-fixes to handle illegal input for tic. Because those did not correspond to useful terminal descriptions, most users are unaffected.
This release provides a new binary format for terminal descriptions that use extended numeric capabilities. Applications built with the wide-character ncursesw library can use these extended numbers.
This includes utilities such as tic and infocmp, because (as noted in New features), the feature relies upon an extension to the low-level tinfo library.
A few software packagers use a configuration option of ncurses which allows the low-level tinfo library to be shared between the high-level ncurses and ncursesw libraries. This new feature was designed to work in that configuration as well.
Other applications (i.e., using the 8-bit ncurses library) which read the extended terminal descriptions see those numeric capabilities set to the maximum value for a signed 16-bit number.
Older versions of ncurses' tic accept out-of-range numeric capabilities, storing those as the maximum value for a signed 16-bit number. Other implementations of curses (mentioned in the discussion of picsmap) give zero for these out-of-range capabilities.
These changes provide support for tack 1.08, released in July 2017:
add --without-tack configure option to refine
--with-progs configure option. Normally
tack is built outside the
ncurses tree, but a few
packagers combine it during the build. If
term_entry.h is installed, there is no advantage
to in-tree builds.
adjust configure-script to define
HAVE_CURSES_DATA_BOOLNAMES symbol needed for
tack 1.08 when built in-tree.
Rather than relying upon internal "_nc_" functions,
tack now uses the boolean,
number and string capability name-arrays provided by
ncurses and SVr4 Unix curses.
It still uses term_entry.h for the definitions
of the extended capability arrays.
add dependency upon ncurses_cfg.h to tic's header-files; any program using tic-library will have to supply this file. Legacy tack versions supply this file; ongoing tack development has dropped the dependency upon tic-library and new releases will not be affected.
Other changes to the configure-script and generated files include
add configure options to disable checks for form, menu and panel libraries so that ncurses-examples can be built with non-SVr4 curses implementations.
add configure option --enable-opaque-curses
for ncurses library and similar options for the
other libraries.
add configure option --disable-wattr-macros
for use in cases where one wants to use the same headers for
ncurses5/ncurses6 development, by suppressing the
wattr* macros which differ due to the introduction
of extended colors
modify configure macro for shared-library rules to use
-Wl,-rpath rather than -rpath to
work around a bug in scons
improve ncurses-examples' configure script to define as
needed NCURSES_WIDECHAR for platforms where
_XOPEN_SOURCE_EXTENDED does not work. Also
modified the test program to ensure that if building with
ncurses, that the
cchar_t type is checked, since that is normally
(since 20111030)
ifdef'd depending on this test.
modify configure script to handle the case where
tic-library is renamed, but
the --with-debug option is used by itself
without normal or shared libraries
modify editing script which generates resulting.map to work with the clang configuration on recent FreeBSD, which gives an error on an empty "local" section.
improve configure check for setting the
WILDCARD_SYMS variable; on ppc64 the variable is
in the Data section rather than
Text.
correct result of configure option
--without-fallbacks, which caused FALLBACK_LIST
to be set to "no"
modify --with-pkg-config-libdir option to
make it possible to install “.pc” files even if
pkg-config is not found. Limit
this change, to suppress the actual install if it is not
overridden to a valid directory at install time.
disallow “no” as a possible value for
--with-shlib-version option, overlooked in
cleanup-changes for 20000708.
Many of the portability changes are implemented via the configure script:
improve configure script's CF_CC_ENV_FLAGS
macro to allow for compiler wrappers such as ccache. This change moves only the
preprocessor, optimization and warning flags to
CPPFLAGS and CFLAGS, leaving the
residue in CC. That happens to work for
gcc's various
“model” options, but may require tuning for other
compilers.
modify ncurses-examples' configure script to use pkg-config for the extra form/menu/panel libraries, to be more consistent with the handling of the curses/ncurses library.
add configuration checks to build with NetBSD
curses, which for example lacks
use_env.
change ncurses-examples to use attr_t vs
chtype to follow X/Open documentation more
closely since Solaris xpg4-curses uses different values for
WA_xxx vs A_xxx
that rely on attr_t being an unsigned short. Tru64 aka OSF1,
HPUX, AIX did as ncurses does,
equating the two sets.
modify several test programs to reflect that ncurses honors existing signal handlers in initscr, while other implementations do not.
add configure check for openpty to
ncurses-examples' configure script, for ditto.
improve check for working poll function by
using posix_openpt as a fallback in case there
is no valid terminal on the standard input
modify ncurses-examples' configure script to check for pthread dependency of ncursest or ncursestw library when building the ncurses examples, e.g., in case weak symbols are used.
add checks in ncurses-examples' configure script for some functions neither in 4.3BSD curses, nor based on X/Open Curses:
modify a loop limit in firework.c to work around absense of limit checks in some libraries.
fill the last row of a window with
“?” in firstlast if waddch does
not return ERR on the lower-right
corner.
build-fixes for the Portland Group (PGI) compilers
accept whitespace in sed expression for generating expanded.c
modify configure check that g++ compiler warnings are not used.
add configure check for -fPIC option needed for shared libraries.
modify configure script for clang as used on FreeBSD, to work around clang's differences in exit codes vs gcc.
fixes for configure/build using clang on OSX
do not redefine “inline” in
ncurses_cfg.h; this was originally to solve
a problem with gcc/g++, but is aggravated by clang's
misuse of symbols to pretend it is gcc.
add braces to configure script to prevent unwanted
addition of “-lstdc++” option to
the CXXLIBS symbol.
improve/update test-program used for checking existence of stdc++ library.
if $CXXLIBS is set, the linkage test uses
that in addition to $LIBS.
fixes for OS/2:
use button instead of kbuf[0] in
EMX-specific part of lib_mouse.c
support building with libtool on OS/2
use stdc++ library with OS/2 kLIBC
clear configure script's cf_XOPEN_SOURCE
for OS/2, to work with its header files
add “newer” baudrate symbols to the
baudrate function in the ncurses library as
well as to a corresponding table in tset.
modify ncurses-examples savescreen to work with AIX and HPUX.
define WIN32_LEAN_AND_MEAN for MinGW port,
making builds faster.
add a configure check for wcwidth versus the ncurses line-drawing characters, to use in special-casing systems such as Solaris. Solaris, however, requires a special case that maps Unicode line-drawing characters into the acsc string for non-Unicode locales. Solaris also has a misconfigured wcwidth which marks all of the line drawing characters as double-width.
string-hacks (non-standard):
fix configure script to record when
strlcat is found on OpenBSD.
add --enable-string-hacks option to
ncurses-examples' configure script.
completed string-hacks for sprintf, etc., including the ncurses-examples programs.
make --enable-string-hacks option work
with Debian by checking for the "bsd" library and its
associated "<bsd/string.h>" header.
workaround for Debian's antique/unmaintained version of mawk:
see Debian #65617, which was fixed in mawk's upstream releases in 2009.
related fixes when building link_test.
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).
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
- cdk
Curses Development Kit
- ded
directory-editor
- dialog
the underlying application used in Slackware's setup, and the basis for similar install/configure applications on many systems.
- lynx
the text WWW browser
- mutt
mail utility
- ncftp
file-transfer utility
- nvi
New vi uses ncurses.
- ranger
A console file manager with VI key bindings in Python.
- tin
newsreader, supporting color, MIME
- vifm
File manager with vi like keybindings
as well as some that use ncurses for the terminfo support alone:
- minicom
terminal emulator for serial modem connections
- mosh
a replacement for
ssh.- tack
terminfo action checker
- tmux
terminal multiplexor
- vile
vi-like-emacs may be built to use the terminfo, termcap or curses interfaces.
and finally, those which use only the termcap interface:
- emacs
text editor
- less
The most commonly used pager (a program that displays text files).
- screen
terminal multiplexor
- vim
text editor
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 Dickey. Thomas Dickey also acts as the maintainer for the Free Software Foundation, which holds the copyright on ncurses.
Contact the current maintainers at
bug-ncurses@gnu.org
To join the ncurses mailing list, please write email to
bug-ncurses-request@gnu.orgcontaining 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 and patches to the current release are made available at
ftp://ftp.invisible-island.net/ncurses/ and
https://invisible-mirror.net/archives/ncurses/ .
There is an archive of the mailing list here:
The release notes make scattered references to these pages, which may be interesting by themselves:
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 .