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 DEBIAN
cg
CG(1)CG(1)NAME
cg - Recursively grep for a pattern and store it.
SYNOPSIS
cg [ -l ] | [ [ -i ] pattern [ files ] ]
DESCRIPTION
cg does a search though text files (usually source code) recursively for a pattern, storing matches and displaying the output in a human-
readable fashion. It is intended to give some of the functionaly of AT&T's cscope(1) tool, with the advantages of simplicity and not being
language-specific. The script will colorize output if configured as such.
It is typically run with a Perl regular expression to search for. The search can be made case insensitive by using the -i option. A list
of files may also be specified with an additional argument after the pattern. Put the files pattern in quotes to make it be matched by
Perl rather than by the shell. Running the script with no arguments will recall the results of the previous search. After the search,
entries found can be edited using the vg(1) script. The -l option shows the last log made.
SOME EXAMPLES
cg - alone recalls the previous search results.
cg -i pattern - search the default list of files for all files matching the pattern (and case-insensitively).
cg pattern '*.c' - search recursively for pattern in all *.c files. This automatically converts '*' to '.*' and '.' to '.' for you and
does a Perl pattern match on all files in the tree.
cg pattern *.c - search through the shell-expanded list of *.c files, so not done recursively (in other words, only the files your shell
pass to the script as arguments).
cg -l - show the last log made.
COMMAND-LINE OPTIONS-i Do a case-insensitive search.
-l Show the last log made.
-p Toggle the default pager option. cg has a bulit-in pager function, which can be enabled or disabled by default (in .cgvgrc). If the
default is enabled, this option disables the pager; if the default is disabled, this option enables it.
-P Force the built-in pager to be disabled.
FILES
${HOME}/.cglast
Log file of the last search.
${HOME}/.cgvgrc
Per-user configuration file (if the defaults are not desireable).
${HOME}/.cgvg/*
Log files in $HOSTNAME.shell_pid form with the log of the last search.
SEE ALSO vg(1), perl(1), find(1), grep(1), cscope(1)AUTHOR
cg was written by Joshua Uziel <uzi@uzix.org>.
13 Mar 2002 CG(1)
06-01-2011
!! Is that possible to knock off 'grep' keyword in perl and can use something native to perl?