ch06_09.htm

the unix power tools

CLASS="emphasis"
>savehist</EM
> (<A
CLASS="linkend"
HREF="ch11_11.htm"
TITLE="Picking Up Where You Left Off "
>11.11</A
>)</SPAN
><A
CLASS="indexterm"
NAME="AUTOID-6423"
></A
>
variable stores the number of lines of shell history 
to be saved when you log out. This amount of history is saved in
a file called <EM
CLASS="emphasis"
>.history</EM
> in your home directory, and
the lines are restored the next time you log in.</P
></LI
><LI
CLASS="listitem"
><P
CLASS="para"
>If you set<A
CLASS="indexterm"
NAME="AUTOID-6428"
></A
>
<SPAN
CLASS="link"
><EM
CLASS="emphasis"
>ignoreeof</EM
> (<A
CLASS="linkend"
HREF="ch03_05.htm"
TITLE="Stop Accidental C Shell Logouts "
>3.5</A
>)</SPAN
>,
the shell won't respond to the end-of-file character (CTRL-d) and will
require you to type <CODE
CLASS="literal"
>logout</CODE
> or
<SPAN
CLASS="link"
><CODE
CLASS="literal"
>exit</CODE
> (<A
CLASS="linkend"
HREF="ch38_04.htm"
TITLE="Subshells "
>38.4</A
>)</SPAN
>
to log out.
This can 
save you from ending the shell accidentally (or logging out).</P
></LI
><LI
CLASS="listitem"
><P
CLASS="para"
>The shell can tell you about new
<SPAN
CLASS="link"
>electronic mail (<A
CLASS="linkend"
HREF="ch01_33.htm"
TITLE="UNIX Networking and Communications "
>1.33</A
>)</SPAN
>
or changes in other files with the
<SPAN
CLASS="link"
><EM
CLASS="emphasis"
>mail</EM
> (<A
CLASS="linkend"
HREF="ch21_08.htm"
TITLE="The MAILCHECK and mail Variables Check More than Mail"
>21.8</A
>)</SPAN
><A
CLASS="indexterm"
NAME="AUTOID-6440"
></A
>
variable.</P
></LI
><LI
CLASS="listitem"
><P
CLASS="para"
>Stop the <CODE
CLASS="literal"
>&gt;</CODE
> redirection character from overwriting files with<A
CLASS="indexterm"
NAME="AUTOID-6445"
></A
><A
CLASS="indexterm"
NAME="AUTOID-6448"
></A
><A
CLASS="indexterm"
NAME="AUTOID-6451"
></A
>
<SPAN
CLASS="link"
><EM
CLASS="emphasis"
>noclobber</EM
> (<A
CLASS="linkend"
HREF="ch13_06.htm"
TITLE="Safe I/O Redirection with noclobber "
>13.6</A
>)</SPAN
>.</P
></LI
><LI
CLASS="listitem"
><P
CLASS="para"
><A
CLASS="indexterm"
NAME="AUTOID-6457"
></A
>The 
<EM
CLASS="emphasis"
>noglob</EM
>
variable stops
<SPAN
CLASS="link"
>wildcard expansion (<A
CLASS="linkend"
HREF="ch15_01.htm#UPT-ART-1480"
TITLE="File Naming Wildcards "
>15.1</A
>)</SPAN
>.
(There's an example in article
<A
CLASS="xref"
HREF="ch05_04.htm"
TITLE="Setting the TERMCAP Variable with tset "
>5.4</A
>.)</P
></LI
><LI
CLASS="listitem"
><P
CLASS="para"
><A
CLASS="indexterm"
NAME="AUTOID-6464"
></A
>Set <EM
CLASS="emphasis"
>nonomatch</EM
>
when you want the C shell to
treat nonmatching wildcards
<SPAN
CLASS="link"
> like the Bourne shell does . (<A
CLASS="linkend"
HREF="ch15_04.htm"
TITLE="What if a Wildcard Doesn't Match? "
>15.4</A
>)</SPAN
></P
></LI
><LI
CLASS="listitem"
><P
CLASS="para"
>The <A
CLASS="indexterm"
NAME="AUTOID-6470"
></A
>
<SPAN
CLASS="link"
><EM
CLASS="emphasis"
>notify</EM
> (<A
CLASS="linkend"
HREF="ch12_06.htm"
TITLE="Notification When Jobs Change State "
>12.6</A
>)</SPAN
>
variable asks the shell to tell you right away if a
background job finishes or is stopped.</P
></LI
><LI
CLASS="listitem"
><P
CLASS="para"
>The list of directories that the shell searches for commands is stored in <A
CLASS="indexterm"
NAME="AUTOID-6476"
></A
>
<SPAN
CLASS="link"
><EM
CLASS="emphasis"
>path</EM
> (<A
CLASS="linkend"
HREF="ch06_05.htm"
TITLE="PATH and path "
>6.5</A
>)</SPAN
>.</P
></LI
><LI
CLASS="listitem"
><P
CLASS="para"
><A
CLASS="indexterm"
NAME="AUTOID-6482"
></A
><A
CLASS="indexterm"
NAME="AUTOID-6484"
></A
>Your login name from the
<SPAN
CLASS="link"
><EM
CLASS="emphasis"
>USER</EM
> or <EM
CLASS="emphasis"
>LOGNAME</EM
> (<A
CLASS="linkend"
HREF="ch06_03.htm"
TITLE="Predefined Environment Variables "
>6.3</A
>)</SPAN
>
environment variable is also stored
in the C shell variable named <EM
CLASS="emphasis"
>user</EM
>.</P
></LI
><LI
CLASS="listitem"
><P
CLASS="para"
>The shell's command-line prompt is set by the <A
CLASS="indexterm"
NAME="AUTOID-6492"
></A
>
<SPAN
CLASS="link"
><EM
CLASS="emphasis"
>prompt</EM
> (<A
CLASS="linkend"
HREF="ch07_02.htm"
TITLE="Basics of Setting the Prompt "
>7.2</A
>)</SPAN
>
variable.
(The
<SPAN
CLASS="link"
><EM
CLASS="emphasis"
>PS1</EM
> (<A
CLASS="linkend"
HREF="ch06_03.htm"
TITLE="Predefined Environment Variables "
>6.3</A
>)</SPAN
><A
CLASS="indexterm"
NAME="AUTOID-6498"
></A
><A
CLASS="indexterm"
NAME="AUTOID-6500"
></A
>
environment variable is the Bourne shell equivalent.
You can set the Bourne shell's
<SPAN
CLASS="link"
>secondary prompt (<A
CLASS="linkend"
HREF="ch09_13.htm"
TITLE="Multiline Commands, Secondary Prompts "
>9.13</A
>)</SPAN
>,
too, in <EM
CLASS="emphasis"
>PS2</EM
>.)&#13;</P
></LI
><LI
CLASS="listitem"
><P
CLASS="para"
><A
CLASS="indexterm"
NAME="AUTOID-6506"
></A
><A
CLASS="indexterm"
NAME="AUTOID-6509"
></A
><A
CLASS="indexterm"
NAME="AUTOID-6511"
></A
>The
<SPAN
CLASS="link"
>exit status (<A
CLASS="linkend"
HREF="ch44_07.htm"
TITLE="Exit Status of UNIX Processes "
>44.7</A
>)</SPAN
>
of the last command is stored in the <EM
CLASS="emphasis"
>csh</EM
> variable named <EM
CLASS="emphasis"
>status</EM
>
and the <EM
CLASS="emphasis"
>sh</EM
> <EM
CLASS="emphasis"
>?</EM
> (question mark) variable.</P
></LI
><LI
CLASS="listitem"
><P
CLASS="para"
>If a job takes more CPU seconds than the number set in the <A
CLASS="indexterm"
NAME="AUTOID-6521"
></A
>
<SPAN
CLASS="link"
><EM
CLASS="emphasis"
>time</EM
> (<A
CLASS="linkend"
HREF="ch39_03.htm"
TITLE="The csh time variable "
>39.3</A
>)</SPAN
>
variable, 
the <EM
CLASS="emphasis"
>csh</EM
> will print a line of statistics about the job.</P
></LI
></UL
><DIV
CLASS="sect1info"
><P
CLASS="SECT1INFO"
>- <SPAN
CLASS="authorinitials"
>JP</SPAN
>, <SPAN
CLASS="authorinitials"
>TOR</SPAN
></P
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