ch42_05.htm

the unix power tools

Or, the screen size may be stored in environment variables called <EM
CLASS="emphasis"
>COLUMNS</EM
>
and <EM
CLASS="emphasis"
>LINES</EM
>:</P
><P
CLASS="para"
><TABLE
CLASS="screen.co"
BORDER="1"
><TR
><TH
VALIGN="TOP"
><PRE
CLASS="calloutlist"
>
<A
CLASS="co"
HREF="ch06_01.htm"
TITLE="6.1 What Environment Variables Are Good For "
>env</A
> <A
CLASS="co"
HREF="ch27_05.htm"
TITLE="27.5 Extended Searching for Text with egrep "
>egrep</A
> 
&#13;</PRE
></TH
><TD
VALIGN="TOP"
><PRE
CLASS="screen"
>
% <CODE
CLASS="userinput"
><B
>env</B
></CODE
><CODE
CLASS="userinput"
><B
> | </B
></CODE
><CODE
CLASS="userinput"
><B
>egrep</B
></CODE
><CODE
CLASS="userinput"
><B
> '(COLUMNS|LINES)='</B
></CODE
>
COLUMNS=80
LINES=24</PRE
></TD
></TR
></TABLE
></P
><P
CLASS="para"
>If the current settings don't match your
<SPAN
CLASS="link"
>screen size (<A
CLASS="linkend"
HREF="ch42_06.htm"
TITLE="Screen Size Testing Files "
>42.6</A
>)</SPAN
>
you can change the screen size settings.
See the suggestions below.</P
></LI
><LI
CLASS="listitem"
><P
CLASS="para"
><A
CLASS="indexterm"
NAME="AUTOID-47071"
></A
><A
CLASS="indexterm"
NAME="AUTOID-47074"
></A
>If UNIX doesn't know your screen size and your system has the <EM
CLASS="emphasis"
>stty size</EM
>
command, you can use <EM
CLASS="emphasis"
>stty</EM
> to change the settings.
For example, if your window has 43 rows and 80 columns, type:</P
><P
CLASS="para"
><BLOCKQUOTE
CLASS="screen"
><PRE
CLASS="screen"
>% <CODE
CLASS="userinput"
><B
>stty rows 43 columns 80</B
></CODE
></PRE
></BLOCKQUOTE
></P
><P
CLASS="para"
>If applications are using the <EM
CLASS="emphasis"
>COLUMNS</EM
> and <EM
CLASS="emphasis"
>LINES</EM
> environment
variables, just
<SPAN
CLASS="link"
>reset them (<A
CLASS="linkend"
HREF="ch06_01.htm#UPT-ART-1170"
TITLE="What Environment Variables Are Good For "
>6.1</A
>)</SPAN
>.</P
><BLOCKQUOTE
CLASS="note"
><P
CLASS="para"
><STRONG
>NOTE:</STRONG
> Any jobs that are stopped or in the background when you change the screen size
may not work anymore because they'll still have the old window size.
If that's a problem, quit and restart the applications or send them a
<EM
CLASS="emphasis"
>SIGWINCH</EM
> signal (below).</P
></BLOCKQUOTE
><P
CLASS="para"
></P
></LI
><LI
CLASS="listitem"
><P
CLASS="para"
><A
CLASS="indexterm"
NAME="AUTOID-47093"
></A
>If you're running <EM
CLASS="emphasis"
>xterm</EM
> in the
<SPAN
CLASS="link"
>X Window System (<A
CLASS="linkend"
HREF="ch01_31.htm"
TITLE="The X Window System "
>1.31</A
>)</SPAN
>,
use <EM
CLASS="emphasis"
>resize</EM
>.
It asks your <EM
CLASS="emphasis"
>xterm</EM
> to report (silently) on how big the window is now,
then it resets the <EM
CLASS="emphasis"
>stty</EM
> parameters or environment variables,
depending on which your system needs.
When it sets environment variables, <EM
CLASS="emphasis"
>resize</EM
> needs to give commands
to the shell.
In the C shell, type:</P
><P
CLASS="para"
><TABLE
CLASS="screen.co"
BORDER="1"
><TR
><TH
VALIGN="TOP"
><PRE
CLASS="calloutlist"
>
<A
CLASS="co"
HREF="ch08_10.htm"
TITLE="8.10 eval: When You Need Another Chance "
>eval</A
> </PRE
></TH
><TD
VALIGN="TOP"
><PRE
CLASS="screen"
>
% <CODE
CLASS="userinput"
><B
>set noglob; </B
></CODE
><CODE
CLASS="userinput"
><B
>eval</B
></CODE
><CODE
CLASS="userinput"
><B
> `resize`</B
></CODE
></PRE
></TD
></TR
></TABLE
></P
><P
CLASS="para"
>(You don't need to use
<SPAN
CLASS="link"
><CODE
CLASS="literal"
>unset noglob</CODE
> (<A
CLASS="linkend"
HREF="ch06_09.htm"
TITLE="Special C Shell Variables "
>6.9</A
>)</SPAN
>
because <EM
CLASS="emphasis"
>resize</EM
> outputs that command.)
In the Bourne shell, </P
><P
CLASS="para"
><BLOCKQUOTE
CLASS="screen"
><PRE
CLASS="screen"
>$ <CODE
CLASS="userinput"
><B
>eval `resize`</B
></CODE
></PRE
></BLOCKQUOTE
></P
><P
CLASS="para"
>Both of these are easier to use if you define an
<SPAN
CLASS="link"
>alias (<A
CLASS="linkend"
HREF="ch10_02.htm"
TITLE="Aliases for Common Commands "
>10.2</A
>)</SPAN
>
or a
<SPAN
CLASS="link"
>shell function (<A
CLASS="linkend"
HREF="ch10_09.htm"
TITLE="Shell Functions "
>10.9</A
>)</SPAN
>
named something like <EM
CLASS="emphasis"
>rs</EM
>:</P
><P
CLASS="para"
><BLOCKQUOTE
CLASS="screen"
><PRE
CLASS="screen"
>alias rs 'set noglob; eval `resize`'
rs() { eval `/usr/bin/X11/resize`; }</PRE
></BLOCKQUOTE
></P
><P
CLASS="para"
></P
></LI
><LI
CLASS="listitem"
><P
CLASS="para"
><A
CLASS="indexterm"
NAME="AUTOID-47123"
></A
>In UNIXes that store the window size as part of the device settings (not
in environment variables), here's another thing you can do.
First, use <EM
CLASS="emphasis"
>stty</EM
> to set the right sizes (see above).
Then send a <EM
CLASS="emphasis"
>SIGWINCH</EM
> (window changed) signal to the shell and/or job
that has a wrong idea of the window size:</P
><P
CLASS="para"
><BLOCKQUOTE
CLASS="screen"
><PRE
CLASS="screen"
>% <CODE
CLASS="userinput"
><B
>kill -WINCH $$</B
></CODE
>    <I
CLASS="lineannotation"
>Send signal to the shell</I
>
% <CODE
CLASS="userinput"
><B
>kill -WINCH %1</B
></CODE
>    <I
CLASS="lineannotation"
>Send signal to job 1</I
></PRE
></BLOCKQUOTE
></P
><P
CLASS="para"
></P
></LI
><LI
CLASS="listitem"
><P
CLASS="para"
>In some window systems, you can make your window a little taller or shorter.
That will reset things.</P
></LI
><LI
CLASS="listitem"
><P
CLASS="para"
><A
CLASS="indexterm"
NAME="AUTOID-47138"
></A
>You're using the
<SPAN
CLASS="link"
><EM
CLASS="emphasis"
>telnet</EM
> (<A
CLASS="linkend"
HREF="ch01_33.htm"
TITLE="UNIX Networking and Communications "
>1.33</A
>)</SPAN
>
command to log in to a remote machine.
You didn't have trouble with the window size on your local
machine&nbsp;- what's wrong?
<EM
CLASS="emphasis"
>telnet</EM
> probably didn't pass your correct window size to the
remote host.
If both the local and remote machines support
<SPAN
CLASS="link"
><EM
CLASS="emphasis"
>rlogin</EM
> (<A
CLASS="linkend"
HREF="ch01_33.htm"
TITLE="UNIX Networking and Communications "
>1.33</A
>)</SPAN
>,
use it instead.
Otherwise, use one of the tips above to set the window size on the
remote system.</P
></LI
></UL
><DIV
CLASS="sect1info"
><P
CLASS="SECT1INFO"
>- <SPAN
CLASS="authorinitials"
>JP</SPAN
></P
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