Perl script to match a pattern and print lines

ammu · #1 (**permalink**) 12-18-2008

Hi
I have a file (say 'file1')and I want to search for a first occurence of pattern (say 'ERROR') and print ten lines in the file below pattern. I have to code it in PERL and I am using Solaris 5.9.

I appreciate any help with code

Thanks
Ammu

FlyingSquirrel · #2 (**permalink**) 12-19-2008

ammu,

Try this script, if it were called... myscript.pl
chmod 755 myscript.pl
cat file1 | ./myscript.pl

#!/usr/bin/env perl

$p=0;
$c=0;
while (<STDIN>) {
if ($p == 0 && m/ERROR/) {
$p=1;
$c=$. + 10;
}

if ($p == 1) {
if ($. < $c) {
print $_;
} else {
last;
}
}
}

summer_cherry · #3 (**permalink**) 12-19-2008

Hi, below package contains serverl method, 'getLinesAfterString' may address your issue.

Code:

package LeoFile;
sub new{
	return bless {};
}
sub _open{
	my $file=shift;
	open FH,"<$file";
}
sub _close{
	close FH;
}
sub _checkPattern{
	my($ref,$pat)=(@_);
	@tmp=@{$ref};
	print "@{$ref}" if($matched==1);
}	
sub getLinesAfterString{
	shift;
	my($file,$str,$line)=(@_);
	_open($file);
	my $cnt;
	while(<FH>){
		$flag=1 if(m/$str/);
		if($flag && $cnt<$line){
			print $_;
			$cnt++;
		}
		else{
			$cnt=0;
			$flag=0;
			next;			
		}
	}
	_close;
}
sub getLinesBetweenString{
	shift;
	my($file,$str1,$str2)=(@_);
	_open($file);
	while(<FH>){
		$flag=1 if(m/$str1/);
		print if ($flag==1);
		$flag=0 if(m/$str2/);
	}
	_close;
}
sub getLinesBetweenStringContainPattern{
	shift;
	my($file,$str1,$str2,$pat)=(@_);
	_open($file);
	while(<FH>){
		$flag=1 if(m/$str1/);
		push @arr,$_ if($flag==1);
		$matched=1 if(m/$pat/);
		if(m/$str2/){
			$flag=0;
			_checkPattern(\@arr,$matched);
			undef @arr;
			$matched=0;
		}
	}
	_close;
}
1

prakash.gr · #4 (**permalink**) 12-19-2008

Hi,

my sorry i wrote wrong wrongly here
Thanks

Prakash

KevinADC · #5 (**permalink**) 12-19-2008

You can use Tie::File and access the file like an array so its easy to jump lines in a file since you can use the line numbers as the array index.

KevinADC · #6 (**permalink**) 12-19-2008

Code:

open (IN, 'file1') or die "$!";
while (<IN>) { 
   if (m/ERROR/) { 
      for (1..10) {
         <IN>;#skips 10 lines
      }
      print;
      last;#stops the "while" loop
   }
}
close IN;

jatanig · #7 (**permalink**) 12-22-2008

Quote:

Originally Posted by ammu

Hi
I have a file (say 'file1')and I want to search for a first occurence of pattern (say 'ERROR') and print ten lines in the file below pattern. I have to code it in PERL and I am using Solaris 5.9.

I appreciate any help with code

Thanks
Ammu

One more Solution:

open(FH, "<file1");
@a=<FH>;
$b=$#a;
for ($n=0;$n<$b;$n++)
{

if ($a[$n]=~/ERROR/)
{
foreach $_ ( @a[$n..($n+10)])
{
print $_;
}
}
}
close(FH);

More UNIX and Linux Forum Topics You Might Find Helpful
Thread	Thread Starter	Forum	Replies	Last Post
retrieve lines that match a pattern	fadista	UNIX for Dummies Questions & Answers	2	12-10-2008 04:40 AM
Match a pattern and copy above two lines	Danish Shakil	Shell Programming and Scripting	16	08-01-2008 02:28 AM
Sed to delete exactly match pattern and print them in other file	new_buddy	Shell Programming and Scripting	3	07-10-2008 03:59 AM
How to delete lines do NOT match a pattern	JumboGeng	UNIX for Dummies Questions & Answers	1	09-20-2006 06:52 AM
match a pattern, print it and the next line	nymus7	Shell Programming and Scripting	4	07-29-2005 01:59 AM

Thread Tools	Search this Thread
Show Printable Version Email this Page	Search this Thread: Advanced Search
Display Modes	Rate This Thread
Switch to Linear Mode Hybrid Mode Switch to Threaded Mode	Rate This Thread:


	Powered by