Hi,
File::Tail can do it for you...

my $count = 0;
my $line;

# from their POD
use File::Tail;
# "tail => -1" will start from the beginning of the file
my $file=File::Tail->new(name => "/some/log/file", tail => -1);
while (defined($line=$file->read)) {
    print ++$count, " ", $line;
}
[download]

Regards,
svenXY

update: added the actual line output to mimic cat -n correctly
update 2: works for me
update 3: added tail => -1 (see comment)