ncurses 6.2 - patch 20210306

[ncurses.git] / man / tput.1

diff --git a/man/tput.1 b/man/tput.1
index 44cedbfcc3532dae27646a46b0a489288e26c64c..8e4a565842c403939dd104018cae08b112d0c232 100644 (file)
--- a/man/tput.1
+++ b/man/tput.1
@@ -1,6 +1,7 @@
 '\" 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            *
@@ -27,7 +28,7 @@
 .\" authorization.                                                           *
 .\"***************************************************************************
 .\"
-.\" $Id: tput.1,v 1.59 2018/07/28 21:30:27 tom Exp $
+.\" $Id: tput.1,v 1.66 2021/03/06 15:56:23 tom Exp $
 .TH @TPUT@ 1 ""
 .ds d @TERMINFO@
 .ds n 1
@@ -271,6 +272,27 @@ If \fB@TPUT@\fR is invoked by a link named \fBinit\fR, this has the
 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
@@ -441,7 +463,7 @@ AT&T or BSD: Ross Ridge's \fImytinfo\fP package, published on
 \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,
@@ -525,6 +547,9 @@ A few platforms such as FreeBSD recognize termcap names rather
 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
@@ -542,13 +567,34 @@ While it is certainly possible to write a \fBtput\fP program
 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@).