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diff --git a/doc/html/man/clear.1.html b/doc/html/man/clear.1.html index 15d8ad5c39e3..e7da4da4f41d 100644 --- a/doc/html/man/clear.1.html +++ b/doc/html/man/clear.1.html @@ -1,6 +1,6 @@ -<!-- +<!-- **************************************************************************** - * Copyright 2018,2020 Thomas E. Dickey * + * 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 * @@ -27,23 +27,21 @@ * sale, use or other dealings in this Software without prior written * * authorization. * **************************************************************************** - * @Id: clear.1,v 1.23 2020/02/02 23:34:34 tom Exp @ - * these would be fallbacks for DS/DE, - * but groff changed the meaning of the macros. + * @Id: clear.1,v 1.48 2024/03/16 15:35:01 tom Exp @ --> <!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01//EN"> <HTML> <HEAD> <meta http-equiv="Content-Type" content="text/html; charset=us-ascii"> <meta name="generator" content="Manpage converted by man2html - see https://invisible-island.net/scripts/readme.html#others_scripts"> -<TITLE>clear 1</TITLE> +<TITLE>clear 1 2024-03-16 ncurses 6.5 User commands</TITLE> <link rel="author" href="mailto:bug-ncurses@gnu.org"> -<meta http-equiv="Content-Type" content="text/html; charset=iso-8859-1"> + </HEAD> <BODY> -<H1 class="no-header">clear 1</H1> +<H1 class="no-header">clear 1 2024-03-16 ncurses 6.5 User commands</H1> <PRE> -<STRONG><A HREF="clear.1.html">clear(1)</A></STRONG> General Commands Manual <STRONG><A HREF="clear.1.html">clear(1)</A></STRONG> +<STRONG><A HREF="clear.1.html">clear(1)</A></STRONG> User commands <STRONG><A HREF="clear.1.html">clear(1)</A></STRONG> @@ -53,108 +51,104 @@ </PRE><H2><a name="h2-SYNOPSIS">SYNOPSIS</a></H2><PRE> - <STRONG>clear</STRONG> [<STRONG>-T</STRONG><EM>type</EM>] [<STRONG>-V</STRONG>] [<STRONG>-x</STRONG>] + <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 screen if this is possible, including its scrollback - buffer (if the extended "E3" capability is defined). <STRONG>clear</STRONG> looks in - the environment for the terminal type given by the environment variable - <STRONG>TERM</STRONG>, and then in the <STRONG>terminfo</STRONG> database to determine how to clear the - screen. + <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 <EM>TERM</EM>, + then consults the <EM>terminfo</EM> terminal capability database entry for that + type to determine how to perform these actions. - <STRONG>clear</STRONG> writes to the standard output. You can redirect the standard - output to a file (which prevents <STRONG>clear</STRONG> from actually clearing the - screen), and later <STRONG>cat</STRONG> the file to the screen, clearing it at that - point. + The capabilities to clear the screen and scrollback buffer are named + "clear" and "E3", respectively. The latter is a <EM>user-defined</EM> + <EM>capability</EM>, applying an extension mechanism introduced in <EM>ncurses</EM> 5.0 + (1999). </PRE><H2><a name="h2-OPTIONS">OPTIONS</a></H2><PRE> - <STRONG>-T</STRONG> <EM>type</EM> - indicates the <EM>type</EM> of terminal. Normally this option is - unnecessary, because the default is taken from the environment - variable <STRONG>TERM</STRONG>. If <STRONG>-T</STRONG> is specified, then the shell variables <STRONG>LINES</STRONG> - and <STRONG>COLUMNS</STRONG> will also be ignored. + <STRONG>clear</STRONG> recognizes the following options. + + <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 <EM>TERM</EM>. If this + option is specified, <STRONG>clear</STRONG> ignores the environment variables + <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. - <STRONG>-V</STRONG> reports the version of ncurses which was used in this program, and - exits. The options are as follows: - <STRONG>-x</STRONG> do not attempt to clear the terminal's scrollback buffer using the - extended "E3" capability. +</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 appeared in 2.79BSD dated February 24, 1979. Later - that was provided in Unix 8th edition (1985). + A <STRONG>clear</STRONG> command using the <EM>termcap</EM> database and library appeared in 2BSD + (1979). Eighth Edition Unix (1985) later included it. - AT&T adapted a different BSD program (<STRONG>tset</STRONG>) to make a new command - (<STRONG>tput</STRONG>), and used this to replace the <STRONG>clear</STRONG> command with a shell script - which calls <STRONG>tput</STRONG> <STRONG>clear</STRONG>, e.g., + 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 - similar to the AT&T <STRONG>tput</STRONG>, he added a shell script for the <STRONG>clear</STRONG> - command: + similar to AT&T's <STRONG>tput</STRONG>, he added a <STRONG>clear</STRONG> shell script as well. exec tput clear The remainder of the script in each case is a copyright notice. - The ncurses <STRONG>clear</STRONG> command began in 1995 by adapting the original BSD - <STRONG>clear</STRONG> command (with terminfo, of course). - - The <STRONG>E3</STRONG> extension came later: + 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, xterm 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 <EM>scrollback</EM> using + one could clear the scrollback buffer as well by using printf '\033[<STRONG>3</STRONG>J' - This is documented in <EM>XTerm</EM> <EM>Control</EM> <EM>Sequences</EM> as a feature - originating with xterm. + instead. "XTerm Control Sequences" documents this feature as + originating with <EM>xterm</EM>. - <STRONG>o</STRONG> A few other terminal developers adopted the feature, e.g., PuTTY in - 2006. + <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 - kernel, modifying its console driver to do the same thing. The - Linux change, part of the 3.0 release, did not mention xterm, - although it was cited in the Red Hat bug report (#683733) which led - to the change. + 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 + report (#683733) motivating the feature. - <STRONG>o</STRONG> Again, a few other terminal developers adopted the feature. But - the next relevant step was a change to the <STRONG>clear</STRONG> program in 2013 to - incorporate this extension. + <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> extension was overlooked in <STRONG>tput</STRONG> with the "clear" - parameter. That 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 tset or reset. - - 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>. + <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 + logic with <STRONG>clear</STRONG> and <STRONG>tset</STRONG>. </PRE><H2><a name="h2-SEE-ALSO">SEE ALSO</a></H2><PRE> - <STRONG><A HREF="tput.1.html">tput(1)</A></STRONG>, <STRONG><A HREF="terminfo.5.html">terminfo(5)</A></STRONG> - - This describes <STRONG>ncurses</STRONG> version 6.2 (patch 20210109). + <STRONG><A HREF="tput.1.html">tput(1)</A></STRONG>, <STRONG>xterm(1)</STRONG>, <STRONG><A HREF="terminfo.5.html">terminfo(5)</A></STRONG> - <STRONG><A HREF="clear.1.html">clear(1)</A></STRONG> +ncurses 6.5 2024-03-16 <STRONG><A HREF="clear.1.html">clear(1)</A></STRONG> </PRE> <div class="nav"> <ul> @@ -162,8 +156,8 @@ <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> |