Reading last few lines from a log file using perl

Hi,

Today I will explain you the program which will help you read whole log file or last given number of lines in a file.

use strict;

my $argc = scalar(@ARGV);

# validate command line arguments
if ($argc eq 0)
{
    print "Error :: Log file not provided\n";
    print "\nUsage\n\n";
    print "$0 \n";
    print "where,\n";
    print "log file name = Fully qualified name of the log file\n";
    print "number of last records = Optional parameter.  Specify the number of last  records you want to read\n";
    exit;
}
my $log_file = $ARGV[0];
my $number_of_records = $ARGV[1];

if (not defined $number_of_records)
{
    $number_of_records = "";
}

unless (-e $log_file)
{
    die "Error :: $log_file doesn't exist\n";
}

# Define variables.

my $current_line = 0; # determine current position in file
my $seek_line = 0; # determines line number where we want to jump and start reading


# Get total number of lines from the file
open (FI, $log_file) or die $!;
while ()
{}
my $lines = $.;
close(FI);

print "\nTotal number of lines in file = $lines\n";

if ($number_of_records ne "")
{
    $seek_line = $lines - $number_of_records;
}

print "Seeking line number $seek_line\n";

open (LOG, $log_file) or die $!;
while ()
{
    my $str = $_;

    $current_line++;
    next if ($current_line <= $seek_line);

    chomp ($str);
    print "line number $current_line: $str\n";
}
close(LOG);