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>Finding Text Within Files</TITLE
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><A
NAME="FINDING-TEXT-WITHIN-FILES"
></A
>Finding Text Within Files</H1
><P
></P
><DIV
CLASS="VARIABLELIST"
><DL
><DT
>grep</DT
><DD
><P
><A
NAME="AEN7976"
></A
>Looks for text within files. For example:</P
><PRE
CLASS="SCREEN"
><SPAN
CLASS="emphasis"
><I
CLASS="EMPHASIS"
>grep this_word this_file.txt</I
></SPAN
> </PRE
><P
>Example options:</P
><P
></P
><UL
><LI
><P
><SPAN
CLASS="emphasis"
><I
CLASS="EMPHASIS"
>-v<A
NAME="AEN7985"
></A
></I
></SPAN
> --- this option is used to display lines <A
NAME="AEN7987"
></A
>which do not contain the string.</P
></LI
><LI
><P
><SPAN
CLASS="emphasis"
><I
CLASS="EMPHASIS"
>-n<A
NAME="AEN7992"
></A
></I
></SPAN
> --- this option displays the line <A
NAME="AEN7994"
></A
>numbers</P
></LI
><LI
><P
><SPAN
CLASS="emphasis"
><I
CLASS="EMPHASIS"
>-w<A
NAME="AEN7999"
></A
></I
></SPAN
> --- this option makes grep <A
NAME="AEN8001"
></A
>match the whole word </P
></LI
><LI
><P
><SPAN
CLASS="emphasis"
><I
CLASS="EMPHASIS"
>-A x </I
></SPAN
>or<SPAN
CLASS="emphasis"
><I
CLASS="EMPHASIS"
> -B </I
></SPAN
>x<A
NAME="AEN8007"
></A
><A
NAME="AEN8009"
></A
> (where x is a number) --- display <A
NAME="AEN8011"
></A
>&ldquo;x&rdquo; lines After or Before the section <A
NAME="AEN8013"
></A
>where the particular <A
NAME="AEN8015"
></A
>word is found.<A
NAME="AEN8017"
></A
> </P
></LI
><LI
><P
><SPAN
CLASS="emphasis"
><I
CLASS="EMPHASIS"
>-r<A
NAME="AEN8022"
></A
></I
></SPAN
> or <SPAN
CLASS="emphasis"
><I
CLASS="EMPHASIS"
>rgrep</I
></SPAN
> --- search for text <A
NAME="AEN8025"
></A
>within files recursively. </P
></LI
></UL
><P
>This command uses regular expressions<A
NAME="AEN8028"
></A
>, for more information <A
NAME="AEN8030"
></A
>please see, <A
HREF="x11655.htm#REGULAR-EXPRESSIONS"
>the Section called <I
>Regular Expressions</I
> in Chapter 20</A
>.</P
><P
>For example, this command would look <A
NAME="AEN8034"
></A
>in the file &ldquo;rpmlist.txt&rdquo; for anything starting <A
NAME="AEN8036"
></A
>with &ldquo;rpm&rdquo;:</P
><PRE
CLASS="SCREEN"
>grep rpm rpmlist.txt</PRE
><P
>Or you could use it like this, to search through the output <A
NAME="AEN8040"
></A
>of another file:</P
><PRE
CLASS="SCREEN"
>rpm -qa | grep ogg<A
NAME="AEN8043"
></A
><A
NAME="AEN8045"
></A
></PRE
><P
>The first command lists <A
NAME="AEN8048"
></A
>all RPM's installed <A
NAME="AEN8050"
></A
>on your system, the second finds<A
NAME="AEN8052"
></A
> any containing the string &ldquo;ogg&rdquo; and outputs <A
NAME="AEN8054"
></A
>them.</P
></DD
><DT
>rgrep</DT
><DD
><P
><A
NAME="AEN8060"
></A
>A &quot;recursive&quot;<A
NAME="AEN8062"
></A
> version <A
NAME="AEN8064"
></A
>of <SPAN
CLASS="emphasis"
><I
CLASS="EMPHASIS"
>grep</I
></SPAN
> (this is a different <A
NAME="AEN8067"
></A
>program to <SPAN
CLASS="emphasis"
><I
CLASS="EMPHASIS"
>grep</I
></SPAN
>). This will search all the files in the current directory <A
NAME="AEN8070"
></A
>and all it's subdirectories and print <A
NAME="AEN8072"
></A
>the names of the files and the matching <A
NAME="AEN8074"
></A
>line. Follows <A
NAME="AEN8076"
></A
>similar syntax <A
NAME="AEN8078"
></A
>to <SPAN
CLASS="emphasis"
><I
CLASS="EMPHASIS"
>grep</I
></SPAN
> (see above). You could also use <SPAN
CLASS="emphasis"
><I
CLASS="EMPHASIS"
>grep</I
></SPAN
> with the <SPAN
CLASS="emphasis"
><I
CLASS="EMPHASIS"
>-r</I
></SPAN
> option <A
NAME="AEN8083"
></A
>to achieve the same affect.<A
NAME="AEN8085"
></A
></P
></DD
><DT
>fgrep</DT
><DD
><P
><A
NAME="AEN8091"
></A
>This version <A
NAME="AEN8093"
></A
>of <SPAN
CLASS="emphasis"
><I
CLASS="EMPHASIS"
>grep</I
></SPAN
> calls <A
NAME="AEN8096"
></A
><SPAN
CLASS="emphasis"
><I
CLASS="EMPHASIS"
>grep</I
></SPAN
> with the <SPAN
CLASS="emphasis"
><I
CLASS="EMPHASIS"
>-F</I
></SPAN
> option. This will look for literal <A
NAME="AEN8100"
></A
>strings only, it won't use or expand <A
NAME="AEN8102"
></A
>any kind of regular <A
NAME="AEN8104"
></A
>expression.</P
><P
>For example you could type:</P
><PRE
CLASS="SCREEN"
>fgrep 'a$*b?' file.txt</PRE
><P
>And <SPAN
CLASS="emphasis"
><I
CLASS="EMPHASIS"
>fgrep</I
></SPAN
> would look for the string &ldquo;a$*b?&rdquo; in the file &ldquo;file.txt&rdquo;.</P
></DD
></DL
></DIV
><DIV
CLASS="TIP"
><BLOCKQUOTE
CLASS="TIP"
><P
><B
>Other Versions: </B
>There are various versions of grep which are designed to do different things try searching for them on the internet or within your distribution.</P
></BLOCKQUOTE
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