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<HTML><!--Distributed by F --><HEAD><TITLE>[Chapter 27] 27.20 A Highlighting grep </TITLE><METANAME="DC.title"CONTENT="UNIX Power Tools"><METANAME="DC.creator"CONTENT="Jerry Peek, Tim O'Reilly & Mike Loukides"><METANAME="DC.publisher"CONTENT="O'Reilly & Associates, Inc."><METANAME="DC.date"CONTENT="1998-08-04T21:44:38Z"><METANAME="DC.type"CONTENT="Text.Monograph"><METANAME="DC.format"CONTENT="text/html"SCHEME="MIME"><METANAME="DC.source"CONTENT="1-56592-260-3"SCHEME="ISBN"><METANAME="DC.language"CONTENT="en-US"><METANAME="generator"CONTENT="Jade 1.1/O'Reilly DocBook 3.0 to HTML 4.0"><LINKREV="made"HREF="mailto:online-books@oreilly.com"TITLE="Online Books Comments"><LINKREL="up"HREF="ch27_01.htm"TITLE="27. Searching Through Files"><LINKREL="prev"HREF="ch27_19.htm"TITLE="27.19 Finding Words Inside Binary Files "><LINKREL="next"HREF="ch28_01.htm"TITLE="28. Comparing Files"></HEAD><BODYBGCOLOR="#FFFFFF"TEXT="#000000"><DIVCLASS="htmlnav"><H1><IMGSRC="gifs/smbanner.gif"ALT="UNIX Power Tools"USEMAP="#srchmap"BORDER="0"></H1><MAPNAME="srchmap"><AREASHAPE="RECT"COORDS="0,0,466,58"HREF="index.htm"ALT="UNIX Power Tools"><AREASHAPE="RECT"COORDS="467,0,514,18"HREF="jobjects/fsearch.htm"ALT="Search this book"></MAP><TABLEWIDTH="515"BORDER="0"CELLSPACING="0"CELLPADDING="0"><TR><TDALIGN="LEFT"VALIGN="TOP"WIDTH="172"><ACLASS="SECT1"HREF="ch27_19.htm"TITLE="27.19 Finding Words Inside Binary Files "><IMGSRC="gifs/txtpreva.gif"SRC="gifs/txtpreva.gif"ALT="Previous: 27.19 Finding Words Inside Binary Files "BORDER="0"></A></TD><TDALIGN="CENTER"VALIGN="TOP"WIDTH="171"><B><FONTFACE="ARIEL,HELVETICA,HELV,SANSERIF"SIZE="-1">Chapter 27<BR>Searching Through Files</FONT></B></TD><TDALIGN="RIGHT"VALIGN="TOP"WIDTH="172"><ACLASS="CHAPTER"HREF="ch28_01.htm"TITLE="28. Comparing Files"><IMGSRC="gifs/txtnexta.gif"SRC="gifs/txtnexta.gif"ALT="Next: 28. Comparing Files"BORDER="0"></A></TD></TR></TABLE> <HRALIGN="LEFT"WIDTH="515"TITLE="footer"></DIV><DIVCLASS="SECT1"><H2CLASS="sect1"><ACLASS="title"NAME="UPT-ART-9038">27.20 A Highlighting grep </A></H2><PCLASS="para"><ACLASS="indexterm"NAME="AUTOID-30912"></A><ACLASS="indexterm"NAME="AUTOID-30914"></A><ACLASS="indexterm"NAME="AUTOID-30917"></A>Does it happen to you that you <EMCLASS="emphasis">grep</EM> for a word, linesscroll down your screen, and it's hard to find the word on each line?For example, suppose I'm looking for any mail messages I've saved thatsay anything about the <EMCLASS="emphasis">perl</EM> programming language.But when I<EMCLASS="emphasis">grep</EM> the file, most of it seems useless:</P><PCLASS="para"><BLOCKQUOTECLASS="screen"><PRECLASS="screen">% <CODECLASS="userinput"><B>grep perl ~/Mail/save</B></CODE>> and some of it wouldn't compile properly. I wonder if Subject: install script, for perl scriptsperl itself is installed?> run but dies with a read error because it isn't properly> if I can get it installed properly on another machine I> run but dies with a read error because it isn't properly > if I can get it installed properly on another machine I</PRE></BLOCKQUOTE></P><TABLECLASS="para.programreference"BORDER="1"><TR><THVALIGN="TOP"><ACLASS="programreference"HREF="examples/index.htm"TITLE="hgrep">hgrep</A><BR></TH><TDVALIGN="TOP"><ACLASS="indexterm"NAME="AUTOID-30926"></A>Well, as described on its own manual page, here's a program that's "trivial, but cute."<EMCLASS="emphasis">hgrep</EM> runs a <EMCLASS="emphasis">grep</EM> and highlights the string being searched for, to make it easier forus to find what we're looking for. </TD></TR></TABLE><PCLASS="para"><BLOCKQUOTECLASS="screen"><PRECLASS="screen">% <CODECLASS="userinput"><B>hgrep perl ~/Mail/save</B></CODE>> and some of it wouldn't compile pro<EMCLASS="emphasis">"<CODECLASS="userinput"><B>perl</B></CODE>"</EM>y. I wonder if Subject: install script, for <EMCLASS="emphasis">"<CODECLASS="userinput"><B>perl</B></CODE>"</EM> scripts<EMCLASS="emphasis"> <CODECLASS="userinput"><B>perl</B></CODE></EM> itself is installed?> run but dies with a read error because it isn't pro<EMCLASS="emphasis"><CODECLASS="userinput"><B>perl</B></CODE></EM>y > if I can get it installed pro<EMCLASS="emphasis"><CODECLASS="userinput"><B>perl</B></CODE></EM>y on another machine I > run but dies with a read error because it isn't pro<EMCLASS="emphasis"><CODECLASS="userinput"><B>perl</B></CODE></EM>y> if I can get it installed pro<EMCLASS="emphasis"><CODECLASS="userinput"><B>perl</B></CODE></EM>y on another machine I</PRE></BLOCKQUOTE></P><PCLASS="para">And now we know why the output looked useless: because most of it is!Luckily, <EMCLASS="emphasis">hgrep</EM> is just a front-end;it simply passes all its arguments to <EMCLASS="emphasis">grep</EM>.So <EMCLASS="emphasis">hgrep</EM>necessarily accepts all of <EMCLASS="emphasis">grep</EM>'s options, and I can just use the<SPANCLASS="link"><EMCLASS="emphasis">-w</EM> option (<ACLASS="linkend"HREF="ch27_04.htm"TITLE="Finding a Pattern Only When It's a Word ">27.4</A>)</SPAN>to weed the output down to what I want:</P><PCLASS="para"><BLOCKQUOTECLASS="screen"><PRECLASS="screen">% <CODECLASS="userinput"><B>hgrep -w perl ~/Mail/save</B></CODE>Subject: install script, for <EMCLASS="emphasis"> <CODECLASS="userinput"><B>perl</B></CODE></EM> scripts<EMCLASS="emphasis"> <CODECLASS="userinput"><B>perl</B></CODE></EM> itself is installed?</PRE></BLOCKQUOTE></P><DIVCLASS="sect1info"><PCLASS="SECT1INFO">- <SPANCLASS="authorinitials">LM</SPAN></P></DIV></DIV><DIVCLASS="htmlnav"><P></P><HRALIGN="LEFT"WIDTH="515"TITLE="footer"><TABLEWIDTH="515"BORDER="0"CELLSPACING="0"CELLPADDING="0"><TR><TDALIGN="LEFT"VALIGN="TOP"WIDTH="172"><ACLASS="SECT1"HREF="ch27_19.htm"TITLE="27.19 Finding Words Inside Binary Files "><IMGSRC="gifs/txtpreva.gif"SRC="gifs/txtpreva.gif"ALT="Previous: 27.19 Finding Words Inside Binary Files "BORDER="0"></A></TD><TDALIGN="CENTER"VALIGN="TOP"WIDTH="171"><ACLASS="book"HREF="index.htm"TITLE="UNIX Power Tools"><IMGSRC="gifs/txthome.gif"SRC="gifs/txthome.gif"ALT="UNIX Power Tools"BORDER="0"></A></TD><TDALIGN="RIGHT"VALIGN="TOP"WIDTH="172"><ACLASS="CHAPTER"HREF="ch28_01.htm"TITLE="28. 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