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a context-revealing grep?

Posted by admin (Graham Ellis), 20 February 2003
Two questions:
1. Can I get grep for windows
2. Is there an option to grep that lets me display a few lines before and a few lines after the match so that I can see matches in context?

Answer:  Here's something (written in Perl) that does it for you - and it will work crossplatform and use Perl's super-extended form of regular expressions!

Code:
#!/usr/bin/perl

$#ARGV < 1 and die ("Usage: $0 regex file [file .. file .. ]\n");
$regex = shift;

foreach $file (@ARGV) {
       open (FH,$file) or warn "Dunno about $file, cobber!\n";
       @content = <FH>;

       for ($k=0; $k<@content; $k++) {
               $gotten = 0;
               if ($content[$k] =~ /$regex/o) {
                       $gotten++ or $#ARGV and
                                       print "*"x20,"in $file\n";
                       print ">>>>>>>>>> Matched from line $k\n";
                       print @content[($k<2?0:$k-2)..$k+2];
                       }
               }
       }


As this isn't a question about the Perl language, but rather an application that happens to be in Perl, I've posted it to the more general information board ....



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