Hi Monks,

I am wanting to print 5 lines before and after a pattern match from a list. I have written the below code but its repeating the loop improperly and writing the lines more than once.

I am sure I am doing something silly but not able to figure it out. Can you anyone of you please help? 

#!/usr/bin/env perl
use strict;
use diagnostics;

open my $read_log, '<', '/home/jayu_rao/test_output/app.log' or die $!
+;
open my $write_tmp_app_log, '>', '/home/jayu_rao/test_output/write_tmp
+_app.log' or die $!;

my @patterns = (
  qr/.*Error.*/,
  qr/.*error.*/,
  qr/.*ERROR.*/,
  qr/.*FATAL.*/,
  qr/.*Critical.*/,
  qr/.*exception.*/,
);

my @lines=<$read_log>;
my $i;

for (@patterns){

for $i (0..$#lines) {
  next unless $lines[$i] =~ $_;
  my $a = $i - 5 < 0 ? 0 : $i - 5;;
  my $b = $i + 5 > $#lines ? $#lines : $i + 5;
  for $i($a..$b){
  print $write_tmp_app_log $lines[$i]
  };
 }
}
close $read_log;
close $write_tmp_app_log;

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In reply to Print 5 lines before and after pattern match from a list by jayu_rao

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