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Full Discussion: Complex Regex Perl
Top Forums Shell Programming and Scripting Complex Regex Perl Post 302671307 by rajkrishna89 on Friday 13th of July 2012 10:33:44 AM
Old 07-13-2012
Complex Regex Perl
Hi the below perl snippet will replace any three letter string in the beginning with a two letter string which is specified..but if i want to modfiy only certain characters for eg..

ABC - AB
CAB - AB
AAA - No Modifcations
1AB - AB
AB8 - AB

Whatever coming before or after of AB only have to be deleted whereas the strings may be left as it is..

Perl Snippet

Code:
use warnings;
use strict;
 
while (<DATA>) {
    chomp;
    s/ ^ [0-9a-z]{3} $ /hi/xi;
    print "$_\n";
}

Thanks Guys!!!!!

Just for additional info guys how to specify spaces in the regex for eg i need to change AB B to AB how the regex to be modified .Thanks for the help guys!!!!!!
 

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LEARN ABOUT CENTOS

ptargrep

PTARGREP(1)						User Contributed Perl Documentation					       PTARGREP(1)

NAME

       ptargrep - Apply pattern matching to the contents of files in a tar archive

SYNOPSIS

	 ptargrep [options] <pattern> <tar file> ...

	 Options:

	  --basename|-b     ignore directory paths from archive
	  --ignore-case|-i  do case-insensitive pattern matching
	  --list-only|-l    list matching filenames rather than extracting matches
	  --verbose|-v	    write debugging message to STDERR
	  --help|-?	    detailed help message

DESCRIPTION

       This utility allows you to apply pattern matching to the contents of files contained in a tar archive.  You might use this to identify all
       files in an archive which contain lines matching the specified pattern and either print out the pathnames or extract the files.

       The pattern will be used as a Perl regular expression (as opposed to a simple grep regex).

       Multiple tar archive filenames can be specified - they will each be processed in turn.

OPTIONS

       --basename (alias -b)
	   When matching files are extracted, ignore the directory path from the archive and write to the current directory using the basename of
	   the file from the archive.  Beware: if two matching files in the archive have the same basename, the second file extracted will
	   overwrite the first.

       --ignore-case (alias -i)
	   Make pattern matching case-insensitive.

       --list-only (alias -l)
	   Print the pathname of each matching file from the archive to STDOUT.  Without this option, the default behaviour is to extract each
	   matching file.

       --verbose (alias -v)
	   Log debugging info to STDERR.

       --help (alias -?)
	   Display this documentation.

COPYRIGHT

       Copyright 2010 Grant McLean <grantm@cpan.org>

       This program is free software; you can redistribute it and/or modify it under the same terms as Perl itself.

perl v5.16.3							    2013-05-12							       PTARGREP(1)
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