* sale, use or other dealings in this Software without prior written *
* authorization. *
****************************************************************************
- * @Id: clear.1,v 1.41 2023/10/07 21:19:07 tom Exp @
+ * @Id: clear.1,v 1.46 2023/12/16 20:32:22 tom Exp @
* https://minnie.tuhs.org/cgi-bin/utree.pl?file=2BSD/src/clear.c
* https://minnie.tuhs.org/cgi-bin/utree.pl?file=Net2/usr/src/usr.bin/\
* tput/clear.sh
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-<TITLE>clear 1 2023-10-07 ncurses 6.4 User commands</TITLE>
+<TITLE>clear 1 2023-12-16 ncurses 6.4 User commands</TITLE>
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-<H1 class="no-header">clear 1 2023-10-07 ncurses 6.4 User commands</H1>
+<H1 class="no-header">clear 1 2023-12-16 ncurses 6.4 User commands</H1>
<PRE>
<STRONG><A HREF="clear.1.html">clear(1)</A></STRONG> User commands <STRONG><A HREF="clear.1.html">clear(1)</A></STRONG>
</PRE><H2><a name="h2-SYNOPSIS">SYNOPSIS</a></H2><PRE>
- <STRONG>clear</STRONG> [<STRONG>-x</STRONG>] [<STRONG>-T</STRONG> <EM>type</EM>]
+ <STRONG>clear</STRONG> [<STRONG>-x</STRONG>] [<STRONG>-T</STRONG> <EM>terminal-type</EM>]
<STRONG>clear</STRONG> <STRONG>-V</STRONG>
</PRE><H2><a name="h2-DESCRIPTION">DESCRIPTION</a></H2><PRE>
<STRONG>clear</STRONG> clears your terminal's screen and its scrollback buffer, if any.
- <STRONG>clear</STRONG> retrieves the terminal type from the environment variable <STRONG>TERM</STRONG>,
+ <STRONG>clear</STRONG> retrieves the terminal type from the environment variable <EM>TERM</EM>,
then consults the <EM>terminfo</EM> terminal capability database entry for that
type to determine how to perform these actions.
<STRONG>-T</STRONG> <EM>type</EM> produces instructions suitable for the terminal <EM>type</EM>.
Normally, this option is unnecessary, because the terminal
- type is inferred from the environment variable <STRONG>TERM</STRONG>. If this
+ type is inferred from the environment variable <EM>TERM</EM>. If this
option is specified, <STRONG>clear</STRONG> ignores the environment variables
- <STRONG>LINES</STRONG> and <STRONG>COLUMNS</STRONG> as well.
+ <EM>LINES</EM> and <EM>COLUMNS</EM> as well.
<STRONG>-V</STRONG> reports the version of <EM>ncurses</EM> associated with this program
and exits with a successful status.
<STRONG>-x</STRONG> prevents <STRONG>clear</STRONG> from attempting to clear the scrollback buffer.
+</PRE><H2><a name="h2-PORTABILITY">PORTABILITY</a></H2><PRE>
+ Neither IEEE Std 1003.1/The Open Group Base Specifications Issue 7
+ (POSIX.1-2008) nor X/Open Curses Issue 7 documents <STRONG>clear</STRONG>.
+
+ The latter documents <STRONG>tput</STRONG>, which could be used to replace this utility
+ either via a shell script or by an alias (such as a symbolic link) to
+ run <STRONG>tput</STRONG> as <STRONG>clear</STRONG>.
+
+
</PRE><H2><a name="h2-HISTORY">HISTORY</a></H2><PRE>
A <STRONG>clear</STRONG> command using the <EM>termcap</EM> database and library appeared in 2BSD
(1979). Eighth Edition Unix (1985) later included it.
- The commercial Unix arm of AT&T adapted a different BSD program (<STRONG>tset</STRONG>)
- to make a new command, <STRONG>tput</STRONG>, and replaced the <STRONG>clear</STRONG> program with a
+ The commercial Unix arm of AT&T adapted a different BSD program (<STRONG>tset</STRONG>)
+ to make a new command, <STRONG>tput</STRONG>, and replaced the <STRONG>clear</STRONG> program with a
shell script that called "<STRONG>tput</STRONG> <STRONG>clear</STRONG>".
/usr/bin/tput ${1:+-T$1} clear 2> /dev/null
exit
- In 1989, when Keith Bostic revised the BSD <STRONG>tput</STRONG> command to make it
+ In 1989, when Keith Bostic revised the BSD <STRONG>tput</STRONG> command to make it
similar to AT&T's <STRONG>tput</STRONG>, he added a <STRONG>clear</STRONG> shell script as well.
exec tput clear
In 1995, <EM>ncurses</EM>'s <STRONG>clear</STRONG> began by adapting BSD's original <STRONG>clear</STRONG> command
to use <EM>terminfo</EM>. The <STRONG>E3</STRONG> extension came later.
- <STRONG>o</STRONG> In June 1999, <EM>xterm</EM> provided an extension to the standard control
- sequence for clearing the screen. Rather than clearing just the
+ <STRONG>o</STRONG> In June 1999, <EM>xterm</EM> provided an extension to the standard control
+ sequence for clearing the screen. Rather than clearing just the
visible part of the screen using
printf '\033[2J'
- one could clear the scrollback buffer using
+ one could clear the scrollback buffer as well by using
printf '\033[<STRONG>3</STRONG>J'
- instead. "XTerm Control Sequences" documents this feature as
+ instead. "XTerm Control Sequences" documents this feature as
originating with <EM>xterm</EM>.
<STRONG>o</STRONG> A few other terminal emulators adopted it, such as PuTTY in 2006.
- <STRONG>o</STRONG> In April 2011, a Red Hat developer submitted a patch to the Linux
+ <STRONG>o</STRONG> In April 2011, a Red Hat developer submitted a patch to the Linux
kernel, modifying its console driver to do the same thing.
- Documentation of this change, appearing in Linux 3.0, did not
- mention <EM>xterm</EM>, although that program was cited in the Red Hat bug
+ Documentation of this change, appearing in Linux 3.0, did not
+ mention <EM>xterm</EM>, although that program was cited in the Red Hat bug
report (#683733) motivating the feature.
- <STRONG>o</STRONG> Subsequently, more terminal developers adopted the feature. The
- next relevant step was to change the <EM>ncurses</EM> <STRONG>clear</STRONG> program in 2013
+ <STRONG>o</STRONG> Subsequently, more terminal developers adopted the feature. The
+ next relevant step was to change the <EM>ncurses</EM> <STRONG>clear</STRONG> program in 2013
to incorporate this extension.
<STRONG>o</STRONG> In 2013, the <STRONG>E3</STRONG> capability was not exercised by "<STRONG>tput</STRONG> <STRONG>clear</STRONG>". That
- oversight was addressed in 2016 by reorganizing <STRONG>tput</STRONG> to share its
+ oversight was addressed in 2016 by reorganizing <STRONG>tput</STRONG> to share its
logic with <STRONG>clear</STRONG> and <STRONG>tset</STRONG>.
-</PRE><H2><a name="h2-PORTABILITY">PORTABILITY</a></H2><PRE>
- Neither IEEE Std 1003.1/The Open Group Base Specifications Issue 7
- (POSIX.1-2008) nor X/Open Curses Issue 7 documents <STRONG>tset</STRONG> or <STRONG>reset</STRONG>.
-
- The latter documents <STRONG>tput</STRONG>, which could be used to replace this utility
- either via a shell script or by an alias (such as a symbolic link) to
- run <STRONG>tput</STRONG> as <STRONG>clear</STRONG>.
-
-
</PRE><H2><a name="h2-SEE-ALSO">SEE ALSO</a></H2><PRE>
<STRONG><A HREF="tput.1.html">tput(1)</A></STRONG>, <STRONG>xterm(1)</STRONG>, <STRONG><A HREF="terminfo.5.html">terminfo(5)</A></STRONG>
-ncurses 6.4 2023-10-07 <STRONG><A HREF="clear.1.html">clear(1)</A></STRONG>
+ncurses 6.4 2023-12-16 <STRONG><A HREF="clear.1.html">clear(1)</A></STRONG>
</PRE>
<div class="nav">
<ul>
<li><a href="#h2-SYNOPSIS">SYNOPSIS</a></li>
<li><a href="#h2-DESCRIPTION">DESCRIPTION</a></li>
<li><a href="#h2-OPTIONS">OPTIONS</a></li>
-<li><a href="#h2-HISTORY">HISTORY</a></li>
<li><a href="#h2-PORTABILITY">PORTABILITY</a></li>
+<li><a href="#h2-HISTORY">HISTORY</a></li>
<li><a href="#h2-SEE-ALSO">SEE ALSO</a></li>
</ul>
</div>