@@ -374,7 +374,7 @@
---------------------------------------------------------------------
0 (capname is a numeric variable that is not specified in
the terminfo(5) database for this terminal type, e.g.
- tput-T450lines and tput-T2621xmc)
+ tput-T450lines and tput-Thp2621xmc)
1 no error message is printed, see the EXITCODES section.
2 usage error
3 unknown terminal type or no terminfo database
@@ -387,102 +387,124 @@
The tput command was begun by Bill Joy in 1980. The initial version
only cleared the screen.
- AT&T System V provided a different tput command, whose init and reset
- subcommands (more than half the program) were incorporated from the
- reset feature of BSD tset written by Eric Allman.
+ AT&T System V provided a different tput command:
+
+ o SVr2 provided a rudimentary tput which checked the parameter
+ against each predefined capability and returned the corresponding
+ value. This version of tput did not use tparm(3x) for the
+ capabilities which are parameterized.
+
+ o SVr3 replaced that, a year later, by a more extensive program whose
+ init and reset subcommands (more than half the program) were
+ incorporated from the reset feature of BSD tset written by Eric
+ Allman.
- Keith Bostic replaced the BSD tput command in 1989 with a new
- implementation based on the AT&T System V program tput. Like the AT&T
- program, Bostic's version accepted some parameters named for terminfo
- capabilities (clear, init, longname and reset). However (because he
- had only termcap available), it accepted termcapnames for other
- capabilities. Also, Bostic's BSD tput did not modify the terminal I/O
+ o SVr4 added color initialization using the orig_colors and orig_pair
+ capabilities in the init subcommand.
+
+ Keith Bostic replaced the BSD tput command in 1989 with a new
+ implementation based on the AT&T System V program tput. Like the AT&T
+ program, Bostic's version accepted some parameters named for terminfo
+ capabilities (clear, init, longname and reset). However (because he
+ had only termcap available), it accepted termcap names for other
+ capabilities. Also, Bostic's BSD tput did not modify the terminal I/O
modes as the earlier BSD tset had done.
At the same time, Bostic added a shell script named "clear", which used
tput to clear the screen.
- Both of these appeared in 4.4BSD, becoming the "modern" BSD
+ Both of these appeared in 4.4BSD, becoming the "modern" BSD
implementation of tput.
- This implementation of tput began from a different source than AT&T or
- BSD: Ross Ridge's mytinfo package, published on comp.sources.unix in
- December 1992. Ridge's program made more sophisticated use of the
- terminal capabilities than the BSD program. Eric Raymond used that
- tput program (and other parts of mytinfo) in ncurses in June 1995.
- Using the portions dealing with terminal capabilities almost without
- change, Raymond made improvements to the way the command-line
+ This implementation of tput began from a different source than AT&T or
+ BSD: Ross Ridge's mytinfo package, published on comp.sources.unix in
+ December 1992. Ridge's program made more sophisticated use of the
+ terminal capabilities than the BSD program. Eric Raymond used that
+ tput program (and other parts of mytinfo) in ncurses in June 1995.
+ Using the portions dealing with terminal capabilities almost without
+ change, Raymond made improvements to the way the command-line
parameters were handled.
- This implementation of tput differs from AT&T tput in two important
+ This implementation of tput differs from AT&T tput in two important
areas:
- otputcapname writes to the standard output. That need not be a
- regular terminal. However, the subcommands which manipulate
+ otputcapname writes to the standard output. That need not be a
+ regular terminal. However, the subcommands which manipulate
terminal modes may not use the standard output.
- The AT&T implementation's init and reset commands use the BSD
- (4.1c) tset source, which manipulates terminal modes. It
- successively tries standard output, standard error, standard input
+ The AT&T implementation's init and reset commands use the BSD
+ (4.1c) tset source, which manipulates terminal modes. It
+ successively tries standard output, standard error, standard input
before falling back to "/dev/tty" and finally just assumes a 1200Bd
terminal. When updating terminal modes, it ignores errors.
- Until changes made after ncurses 6.0, tput did not modify terminal
+ Until changes made after ncurses 6.0, tput did not modify terminal
modes. tput now uses a similar scheme, using functions shared with
- tset (and ultimately based on the 4.4BSD tset). If it is not able
- to open a terminal, e.g., when running in cron, tput will return an
- error.
+ tset (and ultimately based on the 4.4BSD tset). If it is not able
+ to open a terminal, e.g., when running in cron(1), tput will return
+ an error.
o AT&T tput guesses the type of its capname operands by seeing if all
of the characters are numeric, or not.
Most implementations which provide support for capname operands use
- the tparm function to expand parameters in it. That function
- expects a mixture of numeric and string parameters, requiring tput
+ the tparm function to expand parameters in it. That function
+ expects a mixture of numeric and string parameters, requiring tput
to know which type to use.
- This implementation uses a table to determine the parameter types
+ This implementation uses a table to determine the parameter types
for the standard capname operands, and an internal library function
to analyze nonstandard capname operands.
+ Besides providing more reliable operation than AT&T's utility, a
+ portability problem is introduced by this analysis: An OpenBSD
+ developer adapted the internal library function from ncurses to
+ port NetBSD's termcap-based tput to terminfo. That had been
+ modified to interpret multiple commands on a line. Portable
+ applications should not rely upon this feature; ncurses provides it
+ to support applications written specifically for OpenBSD.
+
This implementation (unlike others) can accept both termcap and
- terminfo names for the capname feature, if termcap support is compiled
- in. However, the predefined termcap and terminfo names have two
+ terminfo names for the capname feature, if termcap support is compiled
+ in. However, the predefined termcap and terminfo names have two
ambiguities in this case (and the terminfo name is assumed):
- o The termcap name dl corresponds to the terminfo name dl1 (delete
+ o The termcap name dl corresponds to the terminfo name dl1 (delete
one line).
- The terminfo name dl corresponds to the termcap name DL (delete a
+ The terminfo name dl corresponds to the termcap name DL (delete a
given number of lines).
- o The termcap name ed corresponds to the terminfo name rmdc (end
+ o The termcap name ed corresponds to the terminfo name rmdc (end
delete mode).
- The terminfo name ed corresponds to the termcap name cd (clear to
+ The terminfo name ed corresponds to the termcap name cd (clear to
end of screen).
- The longname and -S options, and the parameter-substitution features
- used in the cup example, were not supported in BSD curses before
+ The longname and -S options, and the parameter-substitution features
+ used in the cup example, were not supported in BSD curses before
4.3reno (1989) or in AT&T/USL curses before SVr4 (1988).
- IEEE Std 1003.1/The Open Group Base Specifications Issue 7
- (POSIX.1-2008) documents only the operands for clear, init and reset.
+ IEEE Std 1003.1/The Open Group Base Specifications Issue 7
+ (POSIX.1-2008) documents only the operands for clear, init and reset.
There are a few interesting observations to make regarding that:
- o In this implementation, clear is part of the capname support. The
- others (init and longname) do not correspond to terminal
+ o In this implementation, clear is part of the capname support. The
+ others (init and longname) do not correspond to terminal
capabilities.
o Other implementations of tput on SVr4-based systems such as
- Solaris, IRIX64 and HPUX as well as others such as AIX and Tru64
+ Solaris, IRIX64 and HPUX as well as others such as AIX and Tru64
provide support for capname operands.
o A few platforms such as FreeBSD recognize termcap names rather than
terminfo capability names in their respective tput commands. Since
- 2010, NetBSD's tput uses terminfo names. Before that, it (like
+ 2010, NetBSD's tput uses terminfo names. Before that, it (like
FreeBSD) recognized termcap names.
+ Beginning in 2021, FreeBSD uses the ncurses tput, configured for
+ both terminfo (tested first) and termcap (as a fallback).
+
Because (apparently) all of the certified Unix systems support the full
set of capability names, the reasoning for documenting only a few may
not be apparent.
@@ -523,7 +545,7 @@