'\" t
.\"***************************************************************************
-.\" Copyright (c) 1998-2012,2016 Free Software Foundation, Inc. *
+.\" Copyright (c) 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 1.44 2016/08/20 23:40:31 tom Exp $
+.\" $Id: tput.1,v 1.51 2017/01/14 20:49:40 tom Exp $
.TH @TPUT@ 1 ""
.ds d @TERMINFO@
.ds n 1
.RS
.TP 5
(1)
-if present, the terminal's initialization strings will be
-output as detailed in the \fBterminfo\fR(5) section on
-.IR "Tabs and Initialization" ,
+first, \fB@TPUT@\fR retrieves the current terminal mode settings
+for your terminal.
+It does this by successively testing
+.RS
+.bP
+the standard error,
+.bP
+standard output,
+.bP
+standard input and
+.bP
+ultimately \*(lq/dev/tty\*(rq
+.RE
+.IP
+to obtain terminal settings.
+Having retrieved these settings, \fB@TPUT@\fP remembers which
+file descriptor to use when updating settings.
.TP
(2)
-any delays (e.g., newline) specified in the entry will
-be set in the tty driver,
+if the window size cannot be obtained from the operating system,
+but the terminal description (or environment, e.g., \fBLINES\fP
+and \fBCOLUMNS\fP variables specify this),
+update the operating system's notion of the window size.
.TP
(3)
+the terminal modes will be updated:
+.RS
+.bP
+any delays (e.g., newline) specified in the entry will
+be set in the tty driver,
+.bP
tabs expansion will be turned on or off according to
the specification in the entry, and
-.TP
-(4)
+.bP
if tabs are not expanded,
standard tabs will be set (every 8 spaces).
.RE
+.TP
+(4)
+if present, the terminal's initialization strings will be
+output as detailed in the \fBterminfo\fR(5) section on
+.IR "Tabs and Initialization" ,
+.TP
+(5)
+output is flushed.
+.RE
.IP
If an entry does not
contain the information needed for any of these activities,
that activity will silently be skipped.
.TP
\fBreset\fR
-Instead of putting out initialization strings, the terminal's
-reset strings will be output if present (\fBrs1\fR, \fBrs2\fR, \fBrs3\fR, \fBrf\fR).
-If the reset strings are not present, but initialization
-strings are, the initialization strings will be output.
+This is similar to \fBinit\fP, with two differences:
+.RS
+.TP 5
+(1)
+before any other initialization,
+the terminal modes will be reset to a \*(``sane\*('' state:
+.RS
+.bP
+set cooked and echo modes,
+.bP
+turn off cbreak and raw modes,
+.bP
+turn on newline translation and
+.bP
+reset any unset special characters to their default values
+.RE
+.TP 5
+(2)
+Instead of putting out \fIinitialization\fP strings, the terminal's
+\fIreset\fP strings will be output if present
+(\fBrs1\fR, \fBrs2\fR, \fBrs3\fR, \fBrf\fR).
+If the \fIreset\fP strings are not present, but \fIinitialization\fP
+strings are, the \fIinitialization\fP strings will be output.
+.RE
+.IP
Otherwise, \fBreset\fR acts identically to \fBinit\fR.
.TP
\fBlongname\fR
name in the first line of the terminal's description in the
\fBterminfo\fR database [see \fBterm\fR(5)].
.SS Aliases
-\fB@TPUT@\fR handles the \fBinit\fP and \fBreset\fP commands specially:
+\fB@TPUT@\fR handles the \fBclear\fP, \fBinit\fP and \fBreset\fP
+commands specially:
it allows for the possibility that it is invoked by a link with those names.
.PP
If \fB@TPUT@\fR is invoked by a link named \fBreset\fR, this has the
same effect as \fB@TPUT@ reset\fR.
-The \fB@TSET@\fR(\*n) utility also treats a link named \fBreset\fP specially:
+The \fB@TSET@\fR(\*n) utility also treats a link named \fBreset\fP specially.
+.PP
+Before ncurses 6.1, the two utilities were different from each other:
.bP
-That utility resets the terminal modes and special characters (not done here).
+\fB@TSET@\fP utility reset the terminal modes and special characters
+(not done with \fB@TPUT@\fP).
.bP
-On the other hand, @TSET@'s repertoire of terminal capabilities for
-resetting the terminal is more limited, i.e., only \fBreset_1string\fP, \fBreset_2string\fP and \fBreset_file\fP
+On the other hand, \fB@TSET@\fP's repertoire of terminal capabilities for
+resetting the terminal was more limited, i.e., only \fBreset_1string\fP, \fBreset_2string\fP and \fBreset_file\fP
in contrast to the tab-stops and margins which are set by this utility.
.bP
-The \fBreset\fP program is usually an alias for @TSET@,
-due to the resetting of terminal modes and special characters.
+The \fBreset\fP program is usually an alias for \fB@TSET@\fP,
+because of this difference with resetting terminal modes and special characters.
+.PP
+With the changes made for ncurses 6.1, the \fIreset\fP feature of the
+two programs is (mostly) the same. A few differences remain:
+.bP
+The \fB@TSET@\fP program waits one second when resetting,
+in case it happens to be a hardware terminal.
+.bP
+The two programs write the terminal initialization strings
+to different streams (i.e.,. the standard error for \fB@TSET@\fP and the
+standard output for \fB@TPUT@\fP).
+.IP
+\fBNote:\fP although these programs write to different streams,
+redirecting their output to a file will capture only part of their actions.
+The changes to the terminal modes are not affected by redirecting the output.
.PP
If \fB@TPUT@\fR is invoked by a link named \fBinit\fR, this has the
same effect as \fB@TPUT@ init\fR.
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.
-Later the corresponding source code for \fIreset\fP
-was removed from the BSD \fBtset\fP
-(in June 1993, released in 4.4BSD-Lite a year later).
.PP
Keith Bostic replaced the BSD \fBtput\fP command in 1989 with a new implementation
based on the AT&T System V program \fBtput\fP.
This implementation of \fBtput\fP differs from AT&T \fBtput\fP in
two important areas:
.bP
-@TPUT@ \fIcapname\fP writes to the standard output.
+\fB@TPUT@\fP \fIcapname\fP 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.
a 1200Bd terminal.
When updating terminal modes, it ignores errors.
.IP
-Until changes made after ncurses 6.0, @TPUT@ did not modify terminal modes.
-@TPUT@ now uses a similar scheme, using functions shared with @TSET@
+Until changes made after ncurses 6.0, \fB@TPUT@\fP did not modify terminal modes.
+\fB@TPUT@\fP now uses a similar scheme,
+using functions shared with \fB@TSET@\fP
(and ultimately based on the 4.4BSD \fBtset\fP).
If it is not able to open a terminal, e.g., when running in \fBcron\fP,
-@TPUT@ will return an error.
+\fB@TPUT@\fP will return an error.
.bP
AT&T \fBtput\fP guesses the type of its \fIcapname\fP operands by seeing if
all of the characters are numeric, or not.
projects / ncurses.git / blobdiff