[Perl] search log v1.0

#!/usr/bin/perl -w 

# Name: search log v1.0
# Author: reistlin
# Website: www.reistlin.com
# Hotfix: bigyong
# Website: www.bigyong.com
# Date: 2010.06.01
# BTW: reistlin`s first perl script :-)

use strict;
use Data::Dumper;

# Debug Switch
my $debug = 0;
# start time
my $time_1 = time();
# clear
system "clear";

# Keyword mode
my $key_file = "key.txt";
my $key_index = 0;
my @key_load;

if ( ! -e $key_file ) {
        print "[Error] \[$key_file\] File does not exist. \n";
        exit;
} else {
        print "[INFO] Load \[$key_file\] Check OK ...\n"
}

# key file details
my @key_stat = stat ($key_file);

print "[INFO] $key_file File Details: \n";
print "UID: $key_stat[4] \n";
print "GID: $key_stat[5] \n";
print "Size: $key_stat[7] bytes \n";
print "Atime: $key_stat[8] \n";
print "Mtime: $key_stat[9] \n";
print "\n";

open (IN, $key_file);

while (<IN>) {
        my $key_line = $_;
        chomp $key_line;
        $key_load[$key_index] = $key_line;
        $key_index++;
}

# Search mode
my $log_file = "log.log";
my $log_index = 0;
my @log_load;

if ( ! -e $log_file ) { 
	print "[Error] \[$log_file\] File does not exist. \n"; 
	exit;
} else {
	print "[INFO] Load \[$log_file\] Check OK ...\n"
} 

# log file details
my @log_stat = stat ($log_file);

print "[INFO] $log_file File Details: \n";
print "UID: $log_stat[4] \n";
print "GID: $log_stat[5] \n";
print "Size: $log_stat[7] bytes \n";
print "Atime: $log_stat[8] \n";
print "Mtime: $log_stat[9] \n";
print "\n";

open (IN, $log_file); 

my $key_load = join("|", @key_load);

while (<IN>) {
	my $log_line = $_;
	chomp $log_line;

	$log_index++;

	if ($log_line =~ /$key_load/) {
		$log_line = "\[$log_index\] $log_line \n";
		push @log_load, $log_line;		
	}
}

# Write Mode
my $result_file = "result.log";

open (IN, "+>" . $result_file);

for ($log_index = 0; $log_index < @log_load; $log_index++) {
	print IN "$log_load[$log_index] \n";
}

if (-e $result_file) {
	print "[INFO] Success \[$result_file\] Saved ... \n";
}

# result file details
my @result_stat = stat ($result_file);
print "[INFO] Result Size: $result_stat[7] bytes \n";

# end time
my $time_2 = time();
my $time = $time_2 - $time_1;
# script runtime
print "[INFO] Runtime \[$time\] Second ... \n";