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<HTML><HEAD><TITLE>Recipe 6.22. Program: tcgrep (Perl Cookbook)</TITLE><METANAME="DC.title"CONTENT="Perl Cookbook"><METANAME="DC.creator"CONTENT="Tom Christiansen & Nathan Torkington"><METANAME="DC.publisher"CONTENT="O'Reilly & Associates, Inc."><METANAME="DC.date"CONTENT="1999-07-02T01:35:09Z"><METANAME="DC.type"CONTENT="Text.Monograph"><METANAME="DC.format"CONTENT="text/html"SCHEME="MIME"><METANAME="DC.source"CONTENT="1-56592-243-3"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="ch06_01.htm"TITLE="6. Pattern Matching"><LINKREL="prev"HREF="ch06_22.htm"TITLE="6.21. Program: urlify"><LINKREL="next"HREF="ch06_24.htm"TITLE="6.23. Regular Expression Grabbag"></HEAD><BODYBGCOLOR="#FFFFFF"><img alt="Book Home" border="0" src="gifs/smbanner.gif" usemap="#banner-map" /><map name="banner-map"><area shape="rect" coords="1,-2,616,66" href="index.htm" alt="Perl Cookbook"><area shape="rect" coords="629,-11,726,25" href="jobjects/fsearch.htm" alt="Search this book" /></map><div class="navbar"><p><TABLEWIDTH="684"BORDER="0"CELLSPACING="0"CELLPADDING="0"><TR><TDALIGN="LEFT"VALIGN="TOP"WIDTH="228"><ACLASS="sect1"HREF="ch06_22.htm"TITLE="6.21. Program: urlify"><IMGSRC="../gifs/txtpreva.gif"ALT="Previous: 6.21. Program: urlify"BORDER="0"></A></TD><TDALIGN="CENTER"VALIGN="TOP"WIDTH="228"><B><FONTFACE="ARIEL,HELVETICA,HELV,SANSERIF"SIZE="-1"><ACLASS="chapter"REL="up"HREF="ch06_01.htm"TITLE="6. Pattern Matching"></A></FONT></B></TD><TDALIGN="RIGHT"VALIGN="TOP"WIDTH="228"><ACLASS="sect1"HREF="ch06_24.htm"TITLE="6.23. Regular Expression Grabbag"><IMGSRC="../gifs/txtnexta.gif"ALT="Next: 6.23. Regular Expression Grabbag"BORDER="0"></A></TD></TR></TABLE></DIV><DIVCLASS="sect1"><H2CLASS="sect1"><ACLASS="title"NAME="ch06-65583">6.22. Program: tcgrep</A></H2><PCLASS="para"><ACLASS="indexterm"NAME="ch06-idx-1000007735-0"></A><ACLASS="indexterm"NAME="ch06-idx-1000007735-1"></A><ACLASS="indexterm"NAME="ch06-idx-1000007735-2"></A><ACLASS="indexterm"NAME="ch06-idx-1000007735-3"></A><ACLASS="indexterm"NAME="ch06-idx-1000007735-4"></A>This program is a Perl rewrite of the Unix <EMCLASS="emphasis">grep</EM> program. Although it runs slower than C versions (especially the GNU <EMCLASS="emphasis">grep</EM>s), it offers many more features.</P><PCLASS="para">The first, and perhaps most important, feature is that it runs anywhere Perl does. Other enhancements are that it can ignore anything that's not a plain text file, automatically expand compressed or <EMCLASS="emphasis">gzip </EM>ped files, recurse down directories, search complete paragraphs or user-defined records, look in younger files before older ones, and add underlining or highlighting of matches. It also supports both the <BCLASS="emphasis.bold">-c</B> option to indicate a count of matching records as well as <BCLASS="emphasis.bold">-C</B> for a count of matching patterns when there could be more than one per record.</P><PCLASS="para">This program uses <EMCLASS="emphasis">gzcat</EM> or <EMCLASS="emphasis">zcat</EM> to decompress compressed files, so this feature is unavailable on systems without these programs and systems without the ability to run external programs (such as the Macintosh).</P><PCLASS="para">Run the program with no arguments for a usage message (see the <CODECLASS="literal">usage</CODE> subroutine in the following code). This command line recursively and case-insensitively greps every file in <EMCLASS="emphasis">~/mail</EM> for mail messages from someone called "kate", reporting the filenames that contained matches.</P><PRECLASS="programlisting">% tcgrep -ril '^From: .*kate' ~/mail</PRE><PCLASS="para">The program is shown in <ACLASS="xref"HREF="ch06_23.htm#ch06-11977"TITLE="tcgrep">Example 6.14</A>.</P><DIVCLASS="example"><H4CLASS="example"><ACLASS="title"NAME="ch06-11977">Example 6.14: tcgrep</A></H4><PRECLASS="programlisting">#!/usr/bin/perl -w# tcgrep: tom christiansen's rewrite of grep# v1.0: Thu Sep 30 16:24:43 MDT 1993# v1.1: Fri Oct 1 08:33:43 MDT 1993# v1.2: Fri Jul 26 13:37:02 CDT 1996# v1.3: Sat Aug 30 14:21:47 CDT 1997# v1.4: Mon May 18 16:17:48 EDT 1998use strict; # globalsuse vars qw($Me $Errors $Grand_Total $Mult %Compress $Matches);my ($matcher, $opt); # matcher - anon. sub to check for matches # opt - ref to hash w/ command line optionsinit(); # initialize globals($opt, $matcher) = parse_args(); # get command line options and patternsmatchfile($opt, $matcher, @ARGV); # process filesexit(2) if $Errors;exit(0) if $Grand_Total;exit(1);###################################sub init { ($Me = $0) =~ s!.*/!!; # get basename of program, "tcgrep" $Errors = $Grand_Total = 0; # initialize global counters $Mult = ""; # flag for multiple files in @ARGV $| = 1; # autoflush output %Compress = ( # file extensions and program names z => 'gzcat', # for uncompressing gz => 'gzcat', Z => 'zcat', );}###################################sub usage { die <<EOFusage: $Me [flags] [files]Standard grep options: i case insensitive n number lines c give count of lines matching C ditto, but >1 match per line possible w word boundaries only s silent mode x exact matches only v invert search sense (lines that DON'T match) h hide filenames e expression (for exprs beginning with -) f file with expressions l list filenames matchingSpecials: 1 1 match per file H highlight matches u underline matches r recursive on directories or dot if none t process directories in 'ls -t' order p paragraph mode (default: line mode) P ditto, but specify separator, e.g. -P '%%\\n' a all files, not just plain text files q quiet about failed file and dir opens T trace files as openedMay use a TCGREP environment variable to set default options.EOF}###################################sub parse_args { use Getopt::Std; my ($optstring, $zeros, $nulls, %opt, $pattern, @patterns, $match_code); my ($SO, $SE); if ($_ = $ENV{TCGREP}) { # get envariable TCGREP s/^([^\-])/-$1/; # add leading - if missing unshift(@ARGV, $_); # add TCGREP opt string to @ARGV } $optstring = "incCwsxvhe:f:l1HurtpP:aqT"; $zeros = 'inCwxvhelut'; # options to init to 0 (prevent warnings) $nulls = 'pP'; # options to init to "" (prevent warnings) @opt{ split //, $zeros } = ( 0 ) x length($zeros); @opt{ split //, $nulls } = ( '' ) x length($nulls); getopts($optstring, \%opt) or usage(); if ($opt{f}) { # -f patfile open(PATFILE, $opt{f}) or die qq($Me: Can't open '$opt{f}': $!); # make sure each pattern in file is valid while ( defined($pattern = <PATFILE>) ) { chomp $pattern; eval { 'foo' =~ /$pattern/, 1 } or die "$Me: $opt{f}:$.: bad pattern: $@"; push @patterns, $pattern; } close PATFILE; } else { # make sure pattern is valid $pattern = $opt{e} || shift(@ARGV) || usage(); eval { 'foo' =~ /$pattern/, 1 } or die "$Me: bad pattern: $@"; @patterns = ($pattern); } if ($opt{H} || $opt{u}) { # highlight or underline my $term = $ENV{TERM} || 'vt100'; my $terminal;⌨️ 快捷键说明
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