+ <B>clear</B> writes to the standard output. You can redirect the standard
+ output to a file (which prevents <B>clear</B> from actually clearing the
+ screen), and later <B>cat</B> the file to the screen, clearing it at that
+ point.
+
+
+</PRE><H2><a name="h2-OPTIONS">OPTIONS</a></H2><PRE>
+ <B>-T</B> <I>type</I>
+ indicates the <I>type</I> of terminal. Normally this option is
+ unnecessary, because the default is taken from the environment
+ variable <B>TERM</B>. If <B>-T</B> is specified, then the shell variables <B>LINES</B>
+ and <B>COLUMNS</B> will also be ignored.
+
+ <B>-V</B> reports the version of ncurses which was used in this program, and
+ exits. The options are as follows:
+
+ <B>-x</B> do not attempt to clear the terminal's scrollback buffer using the
+ extended "E3" capability.
+
+
+</PRE><H2><a name="h2-HISTORY">HISTORY</a></H2><PRE>
+ A <B>clear</B> command appeared in 2.79BSD dated February 24, 1979. Later
+ that was provided in Unix 8th edition (1985).
+
+ AT&T adapted a different BSD program (<B>tset</B>) to make a new command
+ (<B>tput</B>), and used this to replace the <B>clear</B> command with a shell script
+ which calls <B>tput</B> <B>clear</B>, e.g.,
+
+ /usr/bin/tput ${1:+-T$1} clear 2> /dev/null
+ exit
+
+ In 1989, when Keith Bostic revised the BSD <B>tput</B> command to make it
+ similar to the AT&T <B>tput</B>, he added a shell script for the <B>clear</B>
+ command:
+
+ exec tput clear
+
+ The remainder of the script in each case is a copyright notice.
+
+ The ncurses <B>clear</B> command began in 1995 by adapting the original BSD
+ <B>clear</B> command (with terminfo, of course).
+
+ The <B>E3</B> extension came later:
+
+ <B>o</B> In June 1999, xterm 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 <I>scrollback</I> using
+
+ printf '\033[<B>3</B>J'
+
+ This is documented in <I>XTerm</I> <I>Control</I> <I>Sequences</I> as a feature
+ originating with xterm.
+
+ <B>o</B> A few other terminal developers adopted the feature, e.g., PuTTY in
+ 2006.
+
+ <B>o</B> 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.
+
+ <B>o</B> Again, a few other terminal developers adopted the feature. But
+ the next relevant step was a change to the <B>clear</B> program in 2013 to
+ incorporate this extension.
+
+ <B>o</B> In 2013, the <B>E3</B> extension was overlooked in <B>tput</B> with the "clear"
+ parameter. That was addressed in 2016 by reorganizing <B>tput</B> to
+ share its logic with <B>clear</B> and <B>tset</B>.
+
+
+</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 <B>tput</B>, which could be used to replace this utility
+ either via a shell script or by an alias (such as a symbolic link) to
+ run <B>tput</B> as <B>clear</B>.