X-Git-Url: http://ncurses.scripts.mit.edu/?p=ncurses.git;a=blobdiff_plain;f=man%2Ftset.1;h=d64f9850f43e8d68522720094d6bfe8f5ba8ad4f;hp=9743f5b5a7c8423fef4562c4941e2ec680032bb5;hb=HEAD;hpb=96d6b16de0d487e5d3aed0302a179dbce11b5d96

diff --git a/man/tset.1 b/man/tset.1
index 9743f5b5..154d9158 100644
--- a/man/tset.1
+++ b/man/tset.1
@@ -1,5 +1,6 @@
 .\"***************************************************************************
-.\" Copyright (c) 1998-2008,2010 Free Software Foundation, Inc.              *
+.\" Copyright 2018-2023,2024 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            *
@@ -26,258 +27,437 @@
 .\" authorization.                                                           *
 .\"***************************************************************************
 .\"
-.\" $Id: tset.1,v 1.25 2010/12/04 18:38:55 tom Exp $
-.TH @TSET@ 1 ""
+.\" $Id: tset.1,v 1.86 2024/05/11 20:39:53 tom Exp $
+.TH @TSET@ 1 2024-05-11 "ncurses @NCURSES_MAJOR@.@NCURSES_MINOR@" "User commands"
+.ie \n(.g \{\
+.ds `` \(lq
+.ds '' \(rq
+.ds ^  \(ha
+.\}
+.el \{\
+.ie t .ds `` ``
+.el   .ds `` ""
+.ie t .ds '' ''
+.el   .ds '' ""
+.ds       ^  ^
+.\}
+.
+.de bP
+.ie n  .IP \(bu 4
+.el    .IP \(bu 2
+..
+.
 .SH NAME
-\fBtset\fR, \fBreset\fR \- terminal initialization
+\fB\%@TSET@\fP,
+\fB\%@RESET@\fP \-
+initialize or reset terminal state
 .SH SYNOPSIS
-\fBtset\fR [\fB\-IQVcqrsw\fR] [\fB\-\fR] [\fB\-e\fR \fIch\fR] [\fB\-i\fR \fIch\fR] [\fB\-k\fR \fIch\fR] [\fB\-m\fR \fImapping\fR] [\fIterminal\fR]
+\fB@TSET@\fP [\fB\-IQVcqrsw\fP] [\fB\-\fP] [\fB\-e\fP \fIch\fP] [\fB\-i\fP \fIch\fP] [\fB\-k\fP \fIch\fP] [\fB\-m\fP \fImapping\fP] [\fIterminal-type\fP]
 .br
-\fBreset\fR [\fB\-IQVcqrsw\fR] [\fB\-\fR] [\fB\-e\fR \fIch\fR] [\fB\-i\fR \fIch\fR] [\fB\-k\fR \fIch\fR] [\fB\-m\fR \fImapping\fR] [\fIterminal\fR]
+\fB@RESET@\fP [\fB\-IQVcqrsw\fP] [\fB\-\fP] [\fB\-e\fP \fIch\fP] [\fB\-i\fP \fIch\fP] [\fB\-k\fP \fIch\fP] [\fB\-m\fP \fImapping\fP] [\fIterminal-type\fP]
 .SH DESCRIPTION
-\&\fBTset\fR initializes terminals.
-\fBTset\fR first determines the type of terminal that you are using.
+.SS "\fItset\fP \(em initialization"
+This program initializes terminals.
+.PP
+First, \fB@TSET@\fP retrieves the current terminal mode settings
+for your terminal.
+It does this by successively testing
+.bP
+the standard error,
+.bP
+standard output,
+.bP
+standard input and
+.bP
+ultimately \*(``/dev/tty\*(''
+.PP
+to obtain terminal settings.
+Having retrieved these settings, \fB@TSET@\fP remembers which
+file descriptor to use when updating settings.
+.PP
+Next, \fB@TSET@\fP determines the type of terminal that you are using.
 This determination is done as follows, using the first terminal type found.
 .PP
-1. The \fBterminal\fR argument specified on the command line.
+1. The \fBterminal\fP argument specified on the command line.
 .PP
-2. The value of the \fBTERM\fR environmental variable.
+2. The value of the \fITERM\fP environment variable.
 .PP
 3. (BSD systems only.) The terminal type associated with the standard
-error output device in the \fI/etc/ttys\fR file.
-(On System\-V-like UNIXes and systems using that convention,
-\fIgetty\fR does this job by setting
-\fBTERM\fR according to the type passed to it by \fI/etc/inittab\fR.)
-.PP
-4. The default terminal type, ``unknown''.
-.PP
-If the terminal type was not specified on the command-line, the \fB\-m\fR
-option mappings are then applied (see the section
-.B TERMINAL TYPE MAPPING
-for more information).
-Then, if the terminal type begins with a question mark (``?''), the
-user is prompted for confirmation of the terminal type.  An empty
+error output device in the \fI/etc/ttys\fP file.
+(On System\ V hosts and systems using that convention,
+\fI\%getty\fP(8) does this job by setting
+\fITERM\fP according to the type passed to it by \fI\%/etc/inittab\fP.)
+.PP
+4. The default terminal type, \*(``unknown\*('',
+is not suitable for curses applications.
+.PP
+If the terminal type was not specified on the command-line, the \fB\-m\fP
+option mappings are then applied;
+see subsection \*(``Terminal Type Mapping\*(''.
+Then, if the terminal type begins with a question mark (\*(``?\*(''), the
+user is prompted for confirmation of the terminal type.
+An empty
 response confirms the type, or, another type can be entered to specify
-a new type.  Once the terminal type has been determined, the terminfo
-entry for the terminal is retrieved.  If no terminfo entry is found
+a new type.
+Once the terminal type has been determined,
+the terminal description for the terminal is retrieved.
+If no terminal description is found
 for the type, the user is prompted for another terminal type.
 .PP
-Once the terminfo entry is retrieved, the window size, backspace, interrupt
-and line kill characters (among many other things) are set and the terminal
-and tab initialization strings are sent to the standard error output.
+Once the terminal description is retrieved,
+.bP
+if the \*(``\fB\-w\fP\*('' option is enabled, \fB@TSET@\fP may update
+the terminal's window size.
+.IP
+If the window size cannot be obtained from the operating system,
+but the terminal description
+(or environment,
+e.g.,
+\fILINES\fP and \fI\%COLUMNS\fP variables specify this),
+use this to set the operating system's notion of the window size.
+.bP
+if the \*(``\fB\-c\fP\*('' option is enabled,
+the backspace, interrupt and line kill characters
+(among many other things) are set
+.bP
+unless the \*(``\fB\-I\fP\*('' option is enabled,
+the terminal
+and tab \fIinitialization\fP strings are sent to the standard error output,
+and \fB@TSET@\fP waits one second (in case a hardware reset was issued).
+.bP
 Finally, if the erase, interrupt and line kill characters have changed,
 or are not set to their default values, their values are displayed to the
 standard error output.
-Use the \fB\-c\fP or \fB\-w\fP option to select only the window sizing
-versus the other initialization.
-If neither option is given, both are assumed.
-.PP
-When invoked as \fBreset\fR, \fBtset\fR sets cooked and echo modes,
-turns off cbreak and raw modes, turns on newline translation and
-resets any unset special characters to their default values before
-doing the terminal initialization described above.  This is useful
-after a program dies leaving a terminal in an abnormal state.  Note,
+.SS "\fIreset\fP \(em reinitialization"
+When invoked as \fB@RESET@\fP, \fB@TSET@\fP sets the terminal
+modes to \*(``sane\*('' values:
+.bP
+sets cooked and echo modes,
+.bP
+turns off cbreak and raw modes,
+.bP
+turns on newline translation and
+.bP
+resets any unset special characters to their default values
+.PP
+before
+doing the terminal initialization described above.
+Also, rather than using the terminal \fIinitialization\fP strings,
+it uses the terminal \fIreset\fP strings.
+.PP
+The \fB@RESET@\fP command is useful
+after a program dies leaving a terminal in an abnormal state:
+.bP
 you may have to type
 .sp
-    \fB<LF>reset<LF>\fR
+    \fI<LF>\fB@RESET@\fI<LF>\fR
 .sp
 (the line-feed character is normally control-J) to get the terminal
 to work, as carriage-return may no longer work in the abnormal state.
+.bP
 Also, the terminal will often not echo the command.
+.SS "Setting the Environment"
+It is often desirable to enter the terminal type and information about
+the terminal's capabilities into the shell's environment.
+This is done using the \fB\-s\fP option.
+.PP
+When the \fB\-s\fP option is specified, the commands to enter the information
+into the shell's environment are written to the standard output.
+If the \fISHELL\fP environment variable ends in \*(``csh\*('',
+the commands
+are for \fIcsh\fP(1),
+otherwise,
+they are for \fIsh\fP(1).
+The \fIcsh\fP commands set and unset the shell variable \fBnoglob\fP,
+leaving it unset.
+The following line in the \fB.login\fP
+or \fB.profile\fP files will initialize the environment correctly:
+.sp
+    eval \(ga@TSET@ \-s options ... \(ga
+.
+.SS "Terminal Type Mapping"
+When the terminal is not hardwired into the system (or the current
+system information is incorrect) the terminal type derived from the
+\fI/etc/ttys\fP file or the \fITERM\fP environment variable is often
+something generic like \fBnetwork\fP, \fBdialup\fP, or \fBunknown\fP.
+When \fB@TSET@\fP is used in a startup script it is often desirable to
+provide information about the type of terminal used on such ports.
+.PP
+The \fB\-m\fP options maps
+from some set of conditions to a terminal type, that is, to
+tell \fB@TSET@\fP
+\*(``If I'm on this port at a particular speed,
+guess that I'm on that kind of terminal\*(''.
+.PP
+The argument to the \fB\-m\fP option consists of an optional port type, an
+optional operator, an optional baud rate specification, an optional
+colon (\*(``:\*('') character and a terminal type.
+The port type is a
+string (delimited by either the operator or the colon character).
+The operator may be any combination of
+\*(``>\*('',
+\*(``<\*('',
+\*(``@\*('',
+and \*(``!\*('';
+\*(``>\*('' means greater than,
+\*(``<\*('' means less than,
+\*(``@\*('' means equal to and
+\*(``!\*('' inverts the sense of the test.
+The baud rate is specified as a number and is compared with the speed
+of the standard error output (which should be the control terminal).
+The terminal type is a string.
 .PP
+If the terminal type is not specified on the command line, the \fB\-m\fP
+mappings are applied to the terminal type.
+If the port type and baud
+rate match the mapping, the terminal type specified in the mapping
+replaces the current type.
+If more than one mapping is specified, the
+first applicable mapping is used.
+.PP
+For example, consider the following mapping: \fBdialup>9600:vt100\fP.
+The port type is dialup , the operator is >, the baud rate
+specification is 9600, and the terminal type is vt100.
+The result of
+this mapping is to specify that if the terminal type is \fBdialup\fP,
+and the baud rate is greater than 9600 baud, a terminal type of
+\fBvt100\fP will be used.
+.PP
+If no baud rate is specified, the terminal type will match any baud rate.
+If no port type is specified, the terminal type will match any port type.
+For example, \fB\-m dialup:vt100 \-m :?xterm\fP
+will cause any dialup port, regardless of baud rate, to match the terminal
+type vt100, and any non-dialup port type to match the terminal type ?xterm.
+Note, because of the leading question mark, the user will be
+queried on a default port as to whether they are actually using an xterm
+terminal.
+.PP
+No whitespace characters are permitted in the \fB\-m\fP option argument.
+Also, to avoid problems with meta-characters, it is suggested that the
+entire \fB\-m\fP option argument be placed within single quote characters,
+and that \fIcsh\fP users insert a backslash character (\*(``\e\*('')
+before any exclamation marks (\*(``!\*('').
+.SH OPTIONS
 The options are as follows:
 .TP 5
 .B \-c
 Set control characters and modes.
-.B \-e
-Set the erase character to \fIch\fR.
+.TP 5
+.BI \-e\  ch
+Set the erase character to \fIch\fP.
 .TP
 .B \-I
 Do not send the terminal or tab initialization strings to the terminal.
 .TP
-.B \-i
-Set the interrupt character to \fIch\fR.
+.BI \-i\  ch
+Set the interrupt character to \fIch\fP.
 .TP
-.B \-k
-Set the line kill character to \fIch\fR.
+.BI \-k\  ch
+Set the line kill character to \fIch\fP.
 .TP
-.B \-m
-Specify a mapping from a port type to a terminal.
-See the section
-.B TERMINAL TYPE MAPPING
-for more information.
+.BI \-m\  mapping
+Specify a mapping from a port type to a terminal;
+see subsection \*(``Terminal Type Mapping\*(''.
 .TP
 .B \-Q
 Do not display any values for the erase, interrupt and line kill characters.
-Normally \fBtset\fR displays the values for control characters which
+Normally \fB@TSET@\fP displays the values for control characters which
 differ from the system's default values.
 .TP
 .B \-q
 The terminal type is displayed to the standard output, and the terminal is
-not initialized in any way.  The option `\-' by itself is equivalent but
-archaic.
+not initialized in any way.
+The option \*(``\-\*('' by itself is equivalent but archaic.
 .TP
 .B \-r
 Print the terminal type to the standard error output.
 .TP
 .B \-s
 Print the sequence of shell commands to initialize the environment variable
-\fBTERM\fR to the standard output.
-See the section
-.B SETTING THE ENVIRONMENT
-for details.
+\fITERM\fP to the standard output;
+see subsection \*(``Setting the Environment\*(''.
 .TP
 .B \-V
-reports the version of ncurses which was used in this program, and exits.
+reports the version of \fI\%ncurses\fP which was used in this program,
+and exits.
 .TP
 .B \-w
-Resize the window to match the size deduced via \fBsetupterm\fP.
+Resize the window to match the size deduced via \fBsetupterm\fP(3X).
 Normally this has no effect,
 unless \fBsetupterm\fP is not able to detect the window size.
 .PP
-The arguments for the \fB\-e\fR, \fB\-i\fR, and \fB\-k\fR
-options may either be entered as actual characters or by using the `hat'
-notation, i.e., control-h may be specified as ``^H'' or ``^h''.
-.
-.SH SETTING THE ENVIRONMENT
-It is often desirable to enter the terminal type and information about
-the terminal's capabilities into the shell's environment.
-This is done using the \fB\-s\fR option.
-.PP
-When the \fB\-s\fR option is specified, the commands to enter the information
-into the shell's environment are written to the standard output.  If
-the \fBSHELL\fR environmental variable ends in ``csh'', the commands
-are for \fBcsh\fR, otherwise, they are for \fBsh\fR.
-Note, the \fBcsh\fR commands set and unset the shell variable
-\fBnoglob\fR, leaving it unset.  The following line in the \fB.login\fR
-or \fB.profile\fR files will initialize the environment correctly:
-.sp
-    eval \`tset \-s options ... \`
-.
-.SH TERMINAL TYPE MAPPING
-When the terminal is not hardwired into the system (or the current
-system information is incorrect) the terminal type derived from the
-\fI/etc/ttys\fR file or the \fBTERM\fR environmental variable is often
-something generic like \fBnetwork\fR, \fBdialup\fR, or \fBunknown\fR.
-When \fBtset\fR is used in a startup script it is often desirable to
-provide information about the type of terminal used on such ports.
+The arguments for the \fB\-e\fP, \fB\-i\fP, and \fB\-k\fP
+options may either be entered as actual characters
+or by using the \*(``hat\*(''
+notation, i.e., control-h may be specified as \*(``\*^H\*('' or \*(``\*^h\*(''.
 .PP
-The purpose of the \fB\-m\fR option is to map
-from some set of conditions to a terminal type, that is, to
-tell \fBtset\fR
-``If I'm on this port at a particular speed, guess that I'm on that
-kind of terminal''.
+If neither \fB\-c\fP or \fB\-w\fP is given, both options are assumed.
+.SH ENVIRONMENT
+The \fB@TSET@\fP command uses these environment variables:
+.TP 5
+.I SHELL
+tells \fB@TSET@\fP whether to initialize \fITERM\fP using \fIsh\fP(1) or
+\fIcsh\fP(1) syntax.
+.TP 5
+.I TERM
+Denotes your terminal type.
+Each terminal type is distinct, though many are similar.
+.TP 5
+.I TERMCAP
+may denote the location of a termcap database.
+If it is not an absolute pathname, e.g., begins with a \*(``/\*('',
+\fB@TSET@\fP removes the variable from the environment before looking
+for the terminal description.
+.SH FILES
+.TP
+.I /etc/ttys
+system port name to terminal type mapping database (BSD versions only).
+.TP
+.I @TERMINFO@
+compiled terminal description database directory
+.SH PORTABILITY
+Neither IEEE Std 1003.1/The Open Group Base Specifications Issue 7
+(POSIX.1-2008) nor
+X/Open Curses Issue 7 documents \fB@TSET@\fP or \fB@RESET@\fP.
 .PP
-The argument to the \fB\-m\fR option consists of an optional port type, an
-optional operator, an optional baud rate specification, an optional
-colon (``:'') character and a terminal type.  The port type is a
-string (delimited by either the operator or the colon character).  The
-operator may be any combination of ``>'', ``<'', ``@'', and ``!''; ``>''
-means greater than, ``<'' means less than, ``@'' means equal to
-and ``!'' inverts the sense of the test.
-The baud rate is specified as a number and is compared with the speed
-of the standard error output (which should be the control terminal).
-The terminal type is a string.
+The AT&T \fBtput\fP utility (AIX, HP-UX, Solaris)
+incorporated the terminal-mode manipulation as well as termcap-based features
+such as resetting tabstops from \fBtset\fP in BSD (4.1c),
+presumably with the intention of making \fBtset\fP obsolete.
+However, each of those systems still provides \fBtset\fP.
+In fact, the commonly-used \fBreset\fP utility
+is always an alias for \fBtset\fP.
 .PP
-If the terminal type is not specified on the command line, the \fB\-m\fR
-mappings are applied to the terminal type.  If the port type and baud
-rate match the mapping, the terminal type specified in the mapping
-replaces the current type.  If more than one mapping is specified, the
-first applicable mapping is used.
+The \fB\%@TSET@\fP utility provides backward compatibility with BSD
+environments;
+under most modern Unices,
+\fI\%/etc/inittab\fP and \fI\%getty\fP(8) can set \fITERM\fP
+appropriately for each dial-up line,
+obviating what was \fB\%@TSET@\fP's most important use.
+This implementation behaves like 4.4BSD \fBtset\fP,
+with a few exceptions we shall consider now.
 .PP
-For example, consider the following mapping: \fBdialup>9600:vt100\fR.
-The port type is dialup , the operator is >, the baud rate
-specification is 9600, and the terminal type is vt100.  The result of
-this mapping is to specify that if the terminal type is \fBdialup\fR,
-and the baud rate is greater than 9600 baud, a terminal type of
-\fBvt100\fR will be used.
+A few options are different
+because the \fI\%TERMCAP\fP variable
+is no longer supported under terminfo-based \fI\%ncurses\fP:
+.bP
+The \fB\-S\fP option of BSD \fBtset\fP no longer works;
+it prints an error message to the standard error and dies.
+.bP
+The \fB\-s\fP option only sets \fITERM\fP,
+not \fI\%TERMCAP\fP.
 .PP
-If no baud rate is specified, the terminal type will match any baud rate.
-If no port type is specified, the terminal type will match any port type.
-For example, \fB\-m dialup:vt100 \-m :?xterm\fR
-will cause any dialup port, regardless of baud rate, to match the terminal
-type vt100, and any non-dialup port type to match the terminal type ?xterm.
-Note, because of the leading question mark, the user will be
-queried on a default port as to whether they are actually using an xterm
-terminal.
+There was an undocumented 4.4BSD feature
+that invoking \fBtset\fP via a link named
+\*(``TSET\*('' (or via any other name beginning with an upper-case letter)
+set the terminal to use upper-case only.
+This feature has been omitted.
 .PP
-No whitespace characters are permitted in the \fB\-m\fR option argument.
-Also, to avoid problems with meta-characters, it is suggested that the
-entire \fB\-m\fR option argument be placed within single quote characters,
-and that \fBcsh\fR users insert a backslash character (``\e'') before
-any exclamation marks (``!'').
-.SH HISTORY
-The \fBtset\fR command appeared in BSD 3.0.  The \fBncurses\fR implementation
-was lightly adapted from the 4.4BSD sources for a terminfo environment by Eric
-S. Raymond <esr@snark.thyrsus.com>.
-.SH COMPATIBILITY
-The \fBtset\fR utility has been provided for backward-compatibility with BSD
-environments (under most modern UNIXes, \fB/etc/inittab\fR and \fIgetty\fR(1)
-can set \fBTERM\fR appropriately for each dial-up line; this obviates what was
-\fBtset\fR's most important use).  This implementation behaves like 4.4BSD
-tset, with a few exceptions specified here.
-.PP
-The \fB\-S\fR option of BSD tset no longer works; it prints an error message to stderr
-and dies.  The \fB\-s\fR option only sets \fBTERM\fR, not \fBTERMCAP\fP.  Both these
-changes are because the \fBTERMCAP\fR variable is no longer supported under
-terminfo-based \fBncurses\fR, which makes \fBtset \-S\fR useless (we made it die
-noisily rather than silently induce lossage).
-.PP
-There was an undocumented 4.4BSD feature that invoking tset via a link named
-`TSET` (or via any other name beginning with an upper-case letter) set the
-terminal to use upper-case only.  This feature has been omitted.
-.PP
-The \fB\-A\fR, \fB\-E\fR, \fB\-h\fR, \fB\-u\fR and \fB\-v\fR
-options were deleted from the \fBtset\fR
+The \fB\-A\fP, \fB\-E\fP, \fB\-h\fP, \fB\-u\fP and \fB\-v\fP
+options were deleted from the \fB@TSET@\fP
 utility in 4.4BSD.
 None of them were documented in 4.3BSD and all are
 of limited utility at best.
-The \fB\-a\fR, \fB\-d\fR, and \fB\-p\fR options are similarly
+The \fB\-a\fP, \fB\-d\fP, and \fB\-p\fP options are similarly
 not documented or useful, but were retained as they appear to be in
-widespread use.  It is strongly recommended that any usage of these
-three options be changed to use the \fB\-m\fR option instead.  The
-\fB\-n\fP option remains, but has no effect.  The \fB\-adnp\fR options are therefore
-omitted from the usage summary above.
+widespread use.
+It is strongly recommended that any usage of these
+three options be changed to use the \fB\-m\fP option instead.
+The \fB\-a\fP, \fB\-d\fP, and \fB\-p\fP options
+are therefore omitted from the usage summary above.
 .PP
-It is still permissible to specify the \fB\-e\fR, \fB\-i\fR, and \fB\-k\fR options without
-arguments, although it is strongly recommended that such usage be fixed to
+Very old systems, e.g., 3BSD, used a different terminal driver which
+was replaced in 4BSD in the early 1980s.
+To accommodate these older systems, the 4BSD \fB@TSET@\fP provided a
+\fB\-n\fP option to specify that the new terminal driver should be used.
+This implementation does not provide that choice.
+.PP
+It is still permissible to specify the \fB\-e\fP, \fB\-i\fP,
+and \fB\-k\fP options without arguments,
+although it is strongly recommended that such usage be fixed to
 explicitly specify the character.
 .PP
-As of 4.4BSD, executing \fBtset\fR as \fBreset\fR no longer implies the \fB\-Q\fR
-option.  Also, the interaction between the \- option and the \fIterminal\fR
-argument in some historic implementations of \fBtset\fR has been removed.
-.SH ENVIRONMENT
-The \fBtset\fR command uses these environment variables:
-.TP 5
-SHELL
-tells \fBtset\fP whether to initialize \fBTERM\fP using \fBsh\fP or
-\fBcsh\fP syntax.
-.TP 5
-TERM
-Denotes your terminal type.
-Each terminal type is distinct, though many are similar.
-.TP 5
-TERMCAP
-may denote the location of a termcap database.
-If it is not an absolute pathname, e.g., begins with a `/',
-\fBtset\fP removes the variable from the environment before looking
-for the terminal description.
-.SH FILES
-.TP 5
-/etc/ttys
-system port name to terminal type mapping database (BSD versions only).
-.TP
-@TERMINFO@
-terminal capability database
+As of 4.4BSD,
+executing \fB@TSET@\fP as \fB@RESET@\fP no longer implies the \fB\-Q\fP option.
+Also, the interaction between the \- option and the \fIterminal\fP
+argument in some historic implementations of \fB@TSET@\fP has been removed.
+.PP
+The \fB\-c\fP and \fB\-w\fP options are not found in earlier implementations.
+However, a different window size-change feature was provided in 4.4BSD.
+.bP
+In 4.4BSD, \fBtset\fP uses the window size from the termcap description
+to set the window size if \fBtset\fP is not able to obtain the window
+size from the operating system.
+.bP
+In \fI\%ncurses\fP, \fB@TSET@\fP obtains the window size using
+\fB\%setupterm\fP(3X), which may be from
+the operating system,
+the \fILINES\fP and \fICOLUMNS\fP environment variables or
+the terminal description.
+.PP
+Obtaining the window size from a terminal's type description is common
+to both implementations,
+but considered obsolescent.
+Its only practical use is for hardware terminals.
+Generally,
+the window size will remain uninitialized only if there were a problem
+obtaining the value from the operating system
+(and \fB\%setupterm\fP would still fail).
+The \fILINES\fP and \fI\%COLUMNS\fP environment variables
+may thus be useful for working around window-size problems,
+but have the drawback that if the window is resized,
+their values must be recomputed and reassigned.
+The \fI\%resize\fP(1) program distributed with
+\fI\%xterm\fP(1) assists this activity.
+.SH HISTORY
+A \fB\%reset\fP command written by Kurt Shoens appeared in 1BSD
+(March 1978).
+.\" https://minnie.tuhs.org/cgi-bin/utree.pl?file=1BSD/s6/reset.c
+It set the \fIerase\fP and \fIkill\fP characters
+to \fB\*^H\fP (backspace) and \fB@\fP respectively.
+Mark Horton improved this \fB\%reset\fP in 3BSD
+(October 1979),
+adding \fIintr\fP,
+\fIquit\fP,
+\fIstart\fP/\fIstop\fP,
+and \fIeof\fP
+characters as well as changing the program to avoid modifying any user
+settings.
+.\" https://minnie.tuhs.org/cgi-bin/utree.pl?file=3BSD/usr/src/cmd/\
+.\"   reset.c
+That version of \fB\%reset\fP did not use \fI\%termcap\fP.
+.PP
+Eric Allman wrote a distinct \fBtset\fP command for 1BSD,
+using a forerunner of \fI\%termcap\fP called \fI\%ttycap\fP.
+.\" https://minnie.tuhs.org/cgi-bin/utree.pl?file=1BSD/s6/tset.c
+.\" https://minnie.tuhs.org/cgi-bin/utree.pl?file=1BSD/man7/ttycap.7
+Allman's comments in the source code indicate
+that he began work in October 1977,
+continuing development over the next few years.
+By late 1979,
+it had migrated to \fI\%termcap\fP and handled the \fI\%TERMCAP\fP
+variable.
+.\" https://minnie.tuhs.org/cgi-bin/utree.pl?file=3BSD/usr/src/cmd/\
+.\"   tset/tset.c
+Later comments indicate that \fBtset\fP was modified in September 1980
+to use logic copied from the 3BSD \*(``reset\*('' program when it was
+invoked as \fB\%reset\fP.
+.\" https://minnie.tuhs.org/cgi-bin/utree.pl?file=2.9BSD/usr/src/ucb/\
+.\"   tset/tset.c
+This version appeared in 4.1cBSD, \" and backported to 2.9BSD
+late in 1982.
+Other developers such as Keith Bostic and Jim Bloom continued to modify
+\fBtset\fP until 4.4BSD was released in 1993.
+.PP
+The \fI\%ncurses\fP implementation was lightly adapted from the 4.4BSD
+sources to use the \fI\%terminfo\fP API by Eric S.\& Raymond
+<esr@snark.thyrsus.com>.
 .SH SEE ALSO
-csh(1),
-sh(1),
-stty(1),
-curs_terminfo(3X),
-tty(4),
-terminfo(5),
-ttys(5),
-environ(7)
-.PP
-This describes \fBncurses\fR
-version @NCURSES_MAJOR@.@NCURSES_MINOR@ (patch @NCURSES_PATCH@).
+\fB\%csh\fP(1),
+\fB\%sh\fP(1),
+\fB\%stty\fP(1),
+\fB\%curs_terminfo\fP(3X),
+\fB\%tty\fP(4),
+\fB\%terminfo\fP(5),
+\fB\%ttys\fP(5),
+\fB\%environ\fP(7)