- 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 the GNU
- distribution site [1]ftp://ftp.gnu.org/gnu/ncurses/ .
- It is also available at [2]ftp://invisible-island.net/ncurses/ .
-
- Release Notes
-
- This release is designed to be upward compatible from ncurses 5.0 and
- 5.3; very few applications will require recompilation, depending on
- the platform. These are the highlights from the change-log since
- ncurses 5.3 release.
-
- Interface changes:
- * add the remaining functions for X/Open curses wide-character
- support.
- + pecho_wchar()
- + slk_wset()
- These are only available if the library is configured using the
- --enable-widec option.
- * write getyx() and related 2-return macros in terms of getcury(),
- getcurx(), etc.
- * simplify ifdef for bool declaration in curses.h
- * modify ifdef's in curses.h that disabled use of __attribute__()
- for g++, since recent versions implement the cases which ncurses
- uses.
- * add key_defined() function, to tell which keycode a string is
- bound to.
-
- New features and improvements:
- * library
- + implement logic in lib_mouse.c to handle position reports
- which are generated when XFree86 xterm is initialized with
- private modes 1002 or 1003. These are returned to the
- application as the REPORT_MOUSE_POSITION mask, which was not
- implemented.
- + modify soft-key initialization to use A_REVERSE if A_STANDOUT
- would not be shown when colors are used, i.e., if ncv#1 is
- set in the terminfo as is done in "screen".
- + add configure option for FreeBSD sysmouse, --with-sysmouse,
- and implement library support for that.
- * programs:
- + tack:
- o allow it to run from fallback terminfo data.
- o reset colors after each color test, correct a place
- where exit_standout_mode was used instead of
- exit_attribute_mode.
- o improve bce test by making it set colors other than
- black on white.
- + tic:
- o handle a case where an entry has no description, and
- capabilities begin on the same line as the entry name.
- o allow a terminfo entry with a leading 2-character name.
- o improved warnings when suppressing items to fit in
- termcap's 1023-byte limit.
- o add check for multiple "tc=" clauses in a termcap.
- o correct logic for resolving "use=" clauses allow infocmp
- and tic to show cancelled capabilities.
- o check for incomplete line-drawing character mapping.
- o check for missing/empty/illegal terminfo name.
- + tput:
- o modify tput to use the same parameter analysis as
- tparm() does, to provide for user-defined strings, e.g.,
- for xterm title, a corresponding capability might be
- title=\E]2;%p1%s^G,
- + tset:
- o use the system's default values for CKILL and other
- default control characters.
- o correct interchanged defaults for kill and interrupt
- characters, which caused it to report unnecessarily.
-
- Major bug fixes:
- * prevent recursion in wgetch() via wgetnstr() if the connection
- cannot be switched between cooked/raw modes because it is not a
- TTY.
- * correct a case in _nc_remove_string(), used by define_key(), to
- avoid infinite loop if the given string happens to be a substring
- of other strings which are assigned to keys.
- * modify logic of acsc to use the original character if no mapping
- is defined, rather than a null.
- * several improvements for handling multi-cell display of wide
- characters.
- + modify setcchar() to allow converting control characters to
- complex characters.
- + correct handling of multibyte characters in waddch_literal()
- which force wrapping because they are started too late on the
- line.
- + modify setcchar() to allow for wchar_t input strings that
- have more than one spacing character.
- * other fixes for wide-character support:
- + rewrote lib_acs.c to allow PutAttrChar() to decide how to
- render alternate-characters, i.e., to work with Linux console
- and UTF-8 locale.
- + implement a workaround so that line-drawing works with
- screen's crippled UTF-8 support (tested with 3.9.13). This
- only works with the wide-character support (--enable-widec);
- the normal library will simply suppress line-drawing when
- running in a UTF-8 locale in screen.
- + corrections to lib_get_wstr.c:
- o null-terminate buffer passed to setcchar(), which
- occasionally failed.
- o map special characters such as erase- and
- kill-characters into key-codes so those will work as
- expected even if they are not mentioned in the terminfo.
- * modify setupterm() to check if the terminfo and terminal-modes
- have already been read. This ensures that it does not reinvoke
- def_prog_mode() when an application calls more than one function,
- such as tgetent() and initscr().
- * fix form_driver() cases for REQ_CLR_EOF, REQ_CLR_EOL,
- REQ_DEL_CHAR, REQ_DEL_PREV and REQ_NEW_LINE, which did not ensure
- the cursor was at the editing position before making
- modifications.
- * correct keybound(), which reported definitions in the wrong table,
- i.e., the list of definitions which are disabled by keyok().
- * fixes related to safe_sprintf.c:
- + correct an allocation size in safe_sprintf.c for the "*"
- format code.
- + correct safe_sprintf.c to not return a null pointer if the
- format happens to be an empty string.
- + make return value from _nc_printf_string() consistent.
- Before, depending on whether --enable-safe-sprintf was used,
- it might not be cached for reallocating.
- * other low-level improvements to the optimization code include:
- + if the output is a socket or other non-tty device, use 1
- millisecond for the cost in mvcur; previously it was 9
- milliseconds because the baudrate was not known.
- + modify lib_getch.c to avoid recursion via wgetnstr() when the
- input is not a tty and consequently mode-changes do not work.
- + fix several places in tack/pad.c which tested and used the
- parameter- and parameterless strings inconsistently.
- + change several tputs() calls in scrolling code to use putp(),
- to enable padding which may be needed for some terminals.
- + improve mvcur() by checking if it is safe to move when video
- attributes are set (msgr), and if not, reset/restore
- attributes within that function rather than doing it
- separately in the GoTo() function in tty_update.c.
- + use tputs() rather than putp() in a few cases in tty_update.c
- since the corresponding delays are proportional to the number
- of lines affected: repeat_char, clr_eos,
- change_scroll_region.
- * correct line/column reference in adjust_window(), needed to make
- special windows such as curscr track properly when resizing.
- * fix a potential recursion between napms() and _nc_timed_wait()
- * rewrote lib_insch.c, combining it with lib_insstr.c so both handle
- tab and other control characters consistently.
- * do not try to open gpm mouse driver if standard output is not a
- tty; the gpm library does not make this check.
-
- Portability:
- * configure script:
- + new options:
-
- --with-abi-version option.
- addresses platforms where packagers have diverged
- from ncurses ABI numbering.
-
- --with-manpage-format=catonly
- addresses behavior of BSDI, allow install of
- man+cat files on NetBSD, whose behavior has
- diverged by requiring both to be present.
-
- --with-manpage-aliases
- extends "--with-manpage-aliases" to provide the
- option of generating ".so" files rather than
- symbolic links for manpage aliases.
-
- --with-rel-version
- workaround to force libtool on Darwin generate the
- "same" library names as with the "--with-shared"
- option. The Darwin ld program does not work well
- with a zero as the minor-version value.
-
- --with-trace
- simplifies defining TRACE to incorporate trace() in
- libraries.
-
- + fixes/improvements for cross-compiling:
- o allow BUILD_CC and related configure script variables to
- be overridden from the environment.
- o use AC_CHECK_TOOL to get proper values for AR and LD for
- cross compiling.
- o use $cross_compiling variable in configure script rather
- than comparing $host_alias and $target alias, since
- "host" is traditionally misused in autoconf to refer to
- the target platform.
- o modify run_tic.in to avoid using wrong shared libraries
- when cross-compiling.
- + fixes for Mac OS X:
- o fix a redefinition of $RANLIB in the configure script
- when libtool is used.
- o modify MKlib_gen.sh to avoid passing "#" tokens through
- the C preprocessor. This works around Mac OS X's
- preprocessor, which insists on adding a blank on each
- side of the token.
- + workarounds for broken tools:
- o add configure check for wchar_t and wint_t types, rather
- than rely on preprocessor definitions. Also work around
- for gcc fixinclude bug which creates a shadow copy of
- curses.h if it sees these symbols apparently typedef'd.
- o modify configure script to omit -Winline for gcc 3.3,
- since that feature is broken.
- o several script fixes to work around the ironically named
- POSIXLY_CORRECT feature of GNU sed 4.0.
- o modify configure script to avoid using "head -1", which
- does not work if POSIXLY_CORRECT (sic) is set.
- o update configure script to reflect fix for
- AC_PROG_GCC_TRADITIONAL, which is broken in autoconf
- 2.5x for Mac OS X 10.2.3.
- o repair check for missing C++ compiler, which is broken
- in autoconf 2.5x by hardcoding it to g++.
- + corrected ifdef's relating to configure check for wchar_t,
- etc.
- + remove configure script check to allow -Wconversion for older
- versions of gcc
- + modify configure script to accommodate libtool 1.5, as well
- as add an parameter to the "--with-libtool" option which can
- specify the pathname of libtool.
- + change several sed scripts to avoid using "\+" since it is
- not a BRE (basic regular expression). One instance caused
- terminfo.5 to be misformatted on FreeBSD.
- + use '%' as sed substitute delimiter in run_tic script to
- avoid problems with pathname delimiters such as ':' and '@'.
- + add -D_XOPEN_SOURCE=500 if needed when configuring with
- "--enable-widec", to get mbstate_t declaration on HPUX 11.11.
- * library:
- + adjust include-options in CF_ETIP_DEFINES to avoid missing
- ncurses_dll.h, fixing special definitions that may be needed
- for etip.h.
- + modify CF_LIB_SUFFIX for Itanium releases of HP-UX, which use
- a ".so" suffix.
- + improve ifdef's to guard against redefinition of wchar_t and
- wint_t in curses.h.
- + remove an #undef for KEY_EVENT from curses.tail used in the
- experimental NCURSES_WGETCH_EVENTS feature. The #undef
- confuses Debian dpkg's build script.
-
- Features of Ncurses
-
- The ncurses package is fully compatible with SVr4 (System V Release 4)
- 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 SVr4 panels library, supporting a stack of
- windows with backing store, is included.
- * An emulation of the SVr4 menus library, supporting a uniform but
- flexible interface for menu programming, is included.
- * An emulation of the SVr4 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.
+ * 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 6.3, 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:
+ * A new (experimental) driver, for the Windows Terminal
+ configuration is provided.
+ * A script is provided which enables OpenBSD users to upgrade their
+ system to use ncurses 6.3 (OpenBSD developers are also invited to
+ do this).
+
+ Additionally, to improve performance other changes (and extensions)
+ are provided in this release:
+ * modify lib_mouse.c to check for out-of-range button numbers,
+ convert those to position reports.
+ * add sp-funcs for erasewchar, killwchar.
+
+ Other improvements
+
+ These are revised features:
+ * modify wgetnstr, wgetn_wstr to improve compatibility with SVr4
+ curses in its treatment of interrupt and quit characters
+
+ These were done to limit or ultimately deprecate features:
+ * mark wgetch-events feature as deprecated.
+ + prevent KEY_EVENT from appearing in curses.h unless the
+ configure option --enable-wgetch-events is used.
+ + modify MKkey_defs.sh to hide ncurses' definition of
+ KEY_EVENTS to reduce Visual Studio C++ redefinition warnings.
+ * reduce build-warnings by excluding ncurses-internals from
+ deprecation warnings.
+
+ These are improvements to existing features:
+ * drop symbols GCC_PRINTF and GCC_SCANF from <curses.h>, to simplify
+ use.
+ * apply gcc format attribute to prototypes which use a va_list
+ parameter rather than a "..." variable-length parameter list.
+ * modify <term.h> so that it is not necessary to include <curses.h>
+ before <term.h>.
+ * provide for wide-characters as background character in wbkgrnd
+ * improve parameter-checking for tparm, adding function _nc_tiparm()
+ to handle the most-used case, which accepts only numeric
+ parameters.
+ * use return-value from vsnprintf to reallocate as needed to allow
+ for buffers larger than the screen size.
+ * add another fflush(stdout) in _nc_flush to handle time-delays in
+ the middle of strings such as flash when the application uses
+ low-level calls rather than curses.
+
+ These are corrections to existing features:
+ * add a check to guard against repeat_char emitting digits which
+ could be interpreted as BSD-style padding when --enable-bsdpad is
+ configured.
+ * check for screen size-change in scr_init and scr_restore, in case
+ a screen dump does not match the current screen dimensions
+
+ Program improvements
+
+ Several improvements were made to the utility programs:
+
+ tabs
+
+ + implement "+m" option
+
+ tic
+
+ + add check for duplicate "use=" clauses.
+ + add check to report instances where tparm would detect an
+ error in an expression.
+ + add user-defined capabilities from mintty to Caps-ncurses,
+ for checking consistency.
+ + improve warning when oc/op do not mention SGR 39/49 for xterm
+ compatible XT flag.
+ + improve checks for number of parameters of smglp, smgrp,
+ smgtp, and smgbp.
+ + improve "-c" option to validate the number and type of
+ parameters and compare against expected number/type before
+ deciding which set of parameter-lists to use in tparm calls.
+ + improve check for errors detected in tparm.
+ + improve format of output, to ensure that the messages contain
+ only printable text.
+ + modify to eliminate unnecessary "\" to escape ":" in terminfo
+ format.
+ + remove check that assumes that none or both parameterized and
+ non-parameterized margin-setting capabilities are present.
+
+ toe
+
+ + modify output of "toe -as" to show first description found
+ rather than the last.
+ + add a check to ensure that a "termcap file" is text rather
+ than binary.
+
+ tput
+
+ + modify to allow multiple commands per line.
+ + improve parameter-checking by analyzing all extended string
+ capabilities, e.g., as used in the Cs and Ms capabilities of
+ the tmux description.
+ + make warning messages consistently using alias names when
+ those are used, rather than the underlying program's name.
+ + improve usage message for aliases such as clear, by
+ eliminating tput-specific portions.
+ + modify initialization to avoid opening /dev/tty for cases
+ other than reset/init, e.g., for clear.
+
+ 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:
+ * add "-r" option to the dots test-programs, to help with scripting
+ a performance comparison.
+ * build-fix for test_opaque, for configurations without opaque
+ curses structs, e.g., ncurses 5.7.
+ * improve tracemunch logic for "RUN" compaction.
+ * improve tracemunch's coverage of form/menu/panel libraries.
+ * improve tracemunch's checking/reporting the type for the first
+ parameter, e.g., "WINDOW*" rather than "#1".
+ * modify tracemunch and the panel library to show readable traces
+ for panel- and user-pointers.
+
+ 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:
+ * correct use-ordering in some xterm-direct flavors
+ * fix some sgr inconsistencies in d230c, ibm6153, ibm6154,
+ ncrvt100an
+ * improve vt50h and vt52 based on DECScope manual
+ * use hp+arrows in a few places
+ * use hp+pfk-cr in a few places
+ * use vt220+cvis in st, terminology, termite since they ignore
+ blinking-cursor detail in att610+cvis
+
+ 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):
+ * add shifted Linux console keys in linux+sfkeys entry for
+ screen.linux
+ * add Smulx to alacritty
+ * add kbeg to xterm+keypad to accommodate termcap applications
+ * add extensions in xterm+tmux and ecma+strikeout to ms-terminal,
+ but cancel the non-working Cr and Ms capabilities
+
+ 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:
+ + make opts extension for getcchar work as documented for
+ ncurses 6.1, adding "-g" flag to demo_new_pair to illustrate.
+ + modify tset "-q" option to refrain from modifying terminal
+ modes, to match the documentation.
+ * New/improved history and portability sections:
+ + improve documentation for tparm and static/dynamic variables.
+ + add history note to curs_scanw.3x for <stdarg.h> and
+ <varargs.h>
+ + add history note to curs_printw.3x for <stdarg.h> and
+ <varargs.h>
+ + add portability note to ncurses.3x regarding <stdarg.h>
+ + add historical notes to tput, curses-terminfo and
+ curses-color manpages based on source-code for SVr2, SVr3 and
+ SVr4.
+ + improve history section for tset manpage based on the 1BSD
+ tarball, which preceded BSD's SCCS checkins by more than
+ three years.
+ * Other improvements:
+ + explain in ncurses.3x that functions in the tinfo library do
+ not rely upon wide-characters.
+ + improve manual page for panel library, extending the
+ portability section as well as documenting error-returns.
+ + add section on margins to terminfo.5, adapted from X/Open
+ Curses.
+ + improve man/term.5 section on legacy storage format.
+ + add a note in terminfo.5 explaining that no-parameter strings
+ such as sgr0 or cnorm should not be used with tparm.
+ + improve description of BSD-style padding in curs_termcap.3x
+ + improve discussion of padding versus tparm and tputs in
+ man/curs_terminfo.3x
+ + add a note in manual page to explain ungetch vs unget_wch.
+ + improve description of error-returns in waddch and waddnstr
+ manual pages.
+
+ 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:
+ * modify wbkgd and wbkgrnd to avoid storing a null in the background
+ character, because it may be used in cases where the corresponding
+ 0x80 is not treated as a null.
+ This was a regression introduced in ncurses 6.2 (reported on the
+ mailing list), for which the workaround was to specify a blank for
+ the background character.
+ * remove output-related checks for nl/nonl (also reported on the
+ mailing list).
+ * improve tparm implementation of %P and %g, more closely matching
+ SVr4 terminfo. Those denote static and dynamic variables in
+ terminfo expressions.
+ Exactly what those terms meant was never documented before in any
+ implementation of curses, aside from source code. Unlike the other
+ two fixes, the problem was discovered while studying OpenBSD's
+ version of tset.
+
+ 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:
+ * add a special case in the configure script to work around one of
+ the build-time breakages reported for OpenBSD 6 here:
+
+ https://www.mail-archive.com/bugs@openbsd.org/msg13200.html
+ * modify configure check for libtool to prevent accidental use of an
+ OpenBSD program which uses the same name.
+ * modify configuration checks for build-time tic/infocmp to use
+ AC_CHECK_TOOL. That can still be overridden by --with-tic-path and
+ --with-infocmp-path when fallbacks are used, but even if not using
+ fallbacks, the improved check may help with cross-compiling.
+ * relax modification-time comparison in CF_LINK_FUNCS to allow it to
+ accept link() function with NFS filesystems which change the mtime
+ on the link target, e.g., several BSD systems.
+ * modify configure check for c89/c99 aliases of clang to use its
+ -std option instead, because some platforms, in particular macOS,
+ do not provide workable c89/c99 aliases.
+ * modify CF_NCURSES_CONFIG to work around Xcode's c99 "-W" option,
+ which conflicts with conventional use for passing linker options.
+ * modify configure scripts to filter out redefinitions of
+ _XOPEN_SOURCE, e.g., for NetBSD which generally supports 500, but
+ 600 is needed for ncursesw.
+
+ Here are some of the other portability fixes:
+ * change configure-check and source-code for gcc's noreturn
+ attribute to assume it is a prefix rather than suffix, matching
+ c11's _Noreturn convention.
+ * modify mk-1st.awk to account for extra-suffix configure option.
+ * build-fix for termsort module when configured with termcap.
+ * modify configure script and makefiles to support ".PHONY" make
+ program feature.
+ * amend libtool configuration to add dependency for install.tic,
+ etc., in ncurses/Makefile on the lower-level libraries.
+ * modify Ada95 source-generation utility to write to a file given as
+ parameter rather than to the standard output, allowing builds with
+ MinGW.
+ * amend tic/infocmp check to allow for the respective tool's
+ absence.
+ * build-fixes for gnat 10.1.1, whose gnatmake drops integration with
+ gprbuild.
+ * correct configure version-check/warning for g++ to allow for 10.x
+ _________________________________________________________________
+
+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.