'\" t
.\"***************************************************************************
-.\" Copyright (c) 1998-2017,2018 Free Software Foundation, Inc. *
+.\" Copyright 2018-2020,2021 Thomas E. Dickey *
+.\" Copyright 1998-2016,2017 Free Software Foundation, Inc. *
.\" *
.\" Permission is hereby granted, free of charge, to any person obtaining a *
.\" copy of this software and associated documentation files (the *
.\" authorization. *
.\"***************************************************************************
.\"
-.\" $Id: tput.1,v 1.59 2018/07/28 21:30:27 tom Exp $
+.\" $Id: tput.1,v 1.72 2021/10/02 21:41:00 tom Exp $
.TH @TPUT@ 1 ""
.ds d @TERMINFO@
.ds n 1
same effect as \fB@TPUT@ init\fR.
Again, you are less likely to use that link because another program
named \fBinit\fP has a more well-established use.
+.SS Terminal Size
+.PP
+Besides the special commands (e.g., \fBclear\fP),
+@TPUT@ treats certain terminfo capabilities specially:
+\fBlines\fP and \fBcols\fP.
+@TPUT@ calls \fBsetupterm\fP(3X) to obtain the terminal size:
+.bP
+first, it gets the size from the terminal database
+(which generally is not provided for terminal emulators
+which do not have a fixed window size)
+.bP
+then it asks the operating system for the terminal's size
+(which generally works, unless connecting via a serial line which
+does not support \fINAWS\fP: negotiations about window size).
+.bP
+finally, it inspects the environment variables \fBLINES\fP and \fBCOLUMNS\fP
+which may override the terminal size.
+.PP
+If the \fB\-T\fP option is given
+@TPUT@ ignores the environment variables by calling \fBuse_tioctl(TRUE)\fP,
+relying upon the operating system (or finally, the terminal database).
.SH EXAMPLES
.TP 5
\fB@TPUT@ init\fR
\fB0\fR T{
(\fIcapname\fR is a numeric variable that is not specified in the
\fBterminfo\fR(5) database for this terminal type, e.g.
-\fB@TPUT@ \-T450 lines\fR and \fB@TPUT@ \-T2621 xmc\fR)
+\fB@TPUT@ \-T450 lines\fR and \fB@TPUT@ \-Thp2621 xmc\fR)
T}
\fB1\fR no error message is printed, see the \fBEXIT CODES\fR section.
\fB2\fR usage error
The \fBtput\fP command was begun by Bill Joy in 1980.
The initial version only cleared the screen.
.PP
-AT&T System V provided a different \fBtput\fP command,
-whose \fBinit\fP and \fBreset\fP subcommands
+AT&T System V provided a different \fBtput\fP command:
+.bP
+SVr2 provided a rudimentary \fBtput\fP
+which checked the parameter against each
+predefined capability and returned the corresponding value.
+This version of \fBtput\fP did not use \fBtparm\fP(3X) for
+the capabilities which are parameterized.
+.bP
+SVr3 replaced that, a year later, by a more extensive program
+whose \fBinit\fP and \fBreset\fP subcommands
(more than half the program) were incorporated from
the \fBreset\fP feature of BSD \fBtset\fP written by Eric Allman.
+.bP
+SVr4 added color initialization using the \fIorig_colors\fP and
+\fIorig_pairs\fP capabilities in the \fBinit\fP subcommand.
.PP
Keith Bostic replaced the BSD \fBtput\fP command in 1989
with a new implementation
\fIcomp.sources.unix\fP in December 1992.
Ridge's program made more sophisticated use of the terminal capabilities
than the BSD program.
-Eric Raymond used the \fBtput\fP program
+Eric Raymond used that \fBtput\fP program
(and other parts of \fImytinfo\fP) in ncurses in June 1995.
Using the portions dealing with terminal capabilities
almost without change,
This implementation uses a table to determine the parameter types for
the standard \fIcapname\fR operands, and an internal library
function to analyze nonstandard \fIcapname\fR operands.
+.IP
+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 \fBtput\fP 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.
.PP
This implementation (unlike others) can accept both \fItermcap\fP
and \fIterminfo\fP names for the \fIcapname\fP feature,
were not supported in BSD curses before 4.3reno (1989) or in
AT&T/USL curses before SVr4 (1988).
.PP
-IEEE Std 1003.1/The Open Group Base Specifications Issue 7 (POSIX.1-2008)
+IEEE Std 1003.1/The Open Group Base Specifications Issue 7 (POSIX.1-2008)
documents only the operands for \fBclear\fP, \fBinit\fP and \fBreset\fP.
There are a few interesting observations to make regarding that:
.bP
than terminfo capability names in their respective \fBtput\fP commands.
Since 2010, NetBSD's \fBtput\fP uses terminfo names.
Before that, it (like FreeBSD) recognized termcap names.
+.IP
+Beginning in 2021, FreeBSD uses the ncurses \fBtput\fP,
+configured for both terminfo (tested first) and termcap (as a fallback).
.PP
Because (apparently) \fIall\fP of the certified Unix systems
support the full set of capability names, the reasoning for documenting
without using curses,
none of the systems which have a curses implementation provide
a \fBtput\fP utility which does not provide the \fIcapname\fP feature.
+.PP
+X/Open Curses Issue 7 (2009) is the first version to document utilities.
+However that part of X/Open Curses does not follow existing practice
+(i.e., Unix features documented in SVID 3):
+.bP
+It assigns exit code 4 to \*(``invalid operand\*('',
+which may be the same as \fIunknown capability\fP.
+For instance, the source code for Solaris' xcurses uses the term
+\*(``invalid\*('' in this case.
+.bP
+It assigns exit code 255 to a numeric variable that is not specified in
+the terminfo database.
+That likely is a documentation error,
+confusing the \fB\-1\fP written to the standard output for an absent
+or cancelled numeric value versus an (unsigned) exit code.
+.PP
+The various Unix systems (AIX, HPUX, Solaris) use the same exit-codes
+as ncurses.
+.PP
+NetBSD curses documents different exit codes which do not correspond
+to either ncurses or X/Open.
.SH SEE ALSO
\fB@CLEAR@\fR(\*n),
\fBstty\fR(1),
\fB@TABS@\fR(\*n),
\fB@TSET@\fR(\*n),
-\fBterminfo\fR(5),
-\fBcurs_termcap\fR(3X).
+\fBcurs_termcap\fR(3X),
+\fBterminfo\fR(5).
.PP
This describes \fBncurses\fR
version @NCURSES_MAJOR@.@NCURSES_MINOR@ (patch @NCURSES_PATCH@).
projects / ncurses.git / blobdiff