First, just passing a filename as a parameter doesn't automatically open it for reading. You'll have to open it yourself. And you have to enclose any string in quotes (for Perl, ./loghttpd-05212011 is very different from "./loghttpd-05212011").
As for optimizing: don't read line-by-line, define the search regex as strict as possible (can "ERROR" occur anywhere in the line? Or at a specific position? Is there any fixed, or well defined, text leading up to it?), and if possible use the built-in grep function.
A simple example:
Code:
#!/usr/bin/perl -w
use strict;
use warnings;
sub printFun {
my ($file) = @_;
open my $INPUT, '<', $file or die "Can't open $file for reading: $!\n";
print grep { /ERROR/ } <$INPUT>;
close $INPUT;
}
printFun "./loghttpd-05212011";
Thanks a ton Pludi !! Is that possible to knock off 'grep' keyword in perl and can use something native to perl?
For your questions, yes, the pattern 'ERROR' can occur anywhere in the line. It is like "ERROR: " followed by some error messages.
I'm using perl to do a grep of each line in a vendor file and find its occurrences in a specific directory. Any values found is saved in @dir.
.....(file opened, etc.)
....
while ($line=<FILE>){
@dir = `grep $line * `;
}
It's the specific usage of the system grep that I'm having... (7 Replies)
OK here's the situation:
I have got these lines which I have got to parse.
If the line contains a particular string and any element from a previously defined array I need to take that particular line and do some further processing.
if ((grep(/$_/,$1)) && (grep($pattern,@myarr)))
{
#Do... (2 Replies)
Hello
I want to grep a line from a file saved in some directory.
Can anyone please correct the code below:
#!/usr/bin/perl -w
$file = "/home/output.txt"
$grep_line = "closing zip for topic";
`grep $grep_line* $file`; (1 Reply)
Hi All i have this script that uses glob to look in /var/log/messages.*
my @messagefiles = glob "/var/log/messages.*";
and the code that uses it is this
grep { /NVRM: Xid/ } @messages)
but this spits out this
/var/log/messages-20111030:Oct 25 13:43:04 brent kernel: NVRM:... (10 Replies)
Hi,
Can anybody let me know how this grep will work.
The input and output is not known.
Also can you give me the details of any link where i can find clearly about grep
Thanks in advance (1 Reply)
Hi,
i want to create perl script to telnet and print the output. :
This is the script that i have so far :
#!/usr/bin/perl
use lib '/usr/lib/perl5/5.14';
use Telnet ();
$target = "192.168.5.1";
$user = "root";
$passwd = "admin123";
print... (2 Replies)
hello Everyone i am a newbie.
i have a file which contains the following
E:\gtmproj\script\i486_nt\obj\check_geomtools.exe: o:\portsrc\spg\system_1\i486_nt\advapps\TK-2\objmt\winclockmtq.lib
E:\gtmproj\script\i486_nt\obj\check_geomtools.exe:... (12 Replies)
Discussion started by: Rashid Khan
12 Replies
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)
06-01-2011
!! Is that possible to knock off 'grep' keyword in perl and can use something native to perl?