Q2. Parses and prints the HTTP code for the requests from the server log file

ParseHttpCodes.pl

#!/usr/bin/perl

use strict;

printUsage() if ( scalar(@ARGV) != 1 );
open FF, $ARGV[0] or fatal("Unable to open file $ARGV[0]");

my %codeHash;

foreach (<FF>) {
    if (m/HTTP\/.+?\s+(\d+)/) {
        debug($_);
        my $codeCount = 0;
        $codeCount = $codeHash{$1} if ( exists( $codeHash{$1} ) );
        $codeCount++;
        $codeHash{$1} = $codeCount;
    }
}


foreach ( keys(%codeHash) ) {
    info("HTTP code $_ - $codeHash{$_}");
}

#This is specifically added since the question includes printing of 404 errors
if(exists($codeHash{"404"})){
  info("Total 404 errors - $codeHash{'404'}");
} else {
	info("No 404 errors detected in the log");
}

#Helper methods
sub printUsage {
    print "Usage:
	$0 logfilename
";
	exit(2);
}

sub fatal {
    info(shift);
    exit(1);
}

sub info {
    print shift . "\n";
}

sub debug {
    #info(shift);
}