perl grep implementation Post: 302526581

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Top Forums Shell Programming and Scripting perl grep implementation Post 302526581 by royalibrahim on Wednesday 1st of June 2011 01:28:30 AM

06-01-2011

Registered User

perl grep implementation

Hi,

I have a huge log file (~5 GB) generated in my server. I have to search through this file for the pattern matching "ERROR" and print only those lines. There is a Perl script available in the server and I have to add a new subroutine so that it will look for this regular expression pattern in an efficient way. I am not supposed to use 'grep' inside perl.

Since I am new to perl, what I have tried so far is:

Code:

#!/usr/bin/perl -w

sub printFun() {
    while(<>) {
       if ($_=~/ERROR/) {
           print $_;
        }
    }
}

printFun ./loghttpd-05212011

But, I am getting an error "Search pattern not terminated at test.pl line 11" when I run this script. Please help me to solve this issue and get the favored output.

Also, please let me know how to optimize this function (in terms of time consumption) in a better way so that it handles this big data file efficiently

Last edited by royalibrahim; 06-01-2011 at 02:39 AM..

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LEARN ABOUT MOJAVE

ptargrep5.18

PTARGREP(1)						 Perl Programmers Reference Guide					       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 v5.18.2							    2018-08-17							       PTARGREP(1)