Hi, I appreciate your help but I tried to execute your code and I got search command not found error! I tried to use switch command instead but still same error. Your code exits after showing HELP. Finally I was able to fix it :)

#!/usr/bin/perl
use strict;
use warnings;
if ($#ARGV != 1) 
{
print "Error: Usage- script.pl filename keyword(to be searched)\neg:se
+arch.pl config_file XYZ\n";
exit;
}
our $file=$ARGV[0];
our $key=$ARGV[1];
my $count = 0;
    if (-e "$file")
    {
    open (DATA,$file); 
    chomp($key);
    # Search for the key pattern in the file information.
    while (defined (my $line = <DATA>)) 
        {
            if ($line =~ /\b\Q$key\E\b/i)
            {
            #next;
                print "$line\n";
            $count++;
            } 
        }
    if($count == 0)
        {
        print "Keyword not found\n Search Completed\n";
        }
    close (DATA);
    }
    else 
    {
        print "Error: file does'nt exist\n";
        exit;
    }
[download]

NOTE: This can be run as script.pl randomfile randomkey format