open(FILE, "<x.log");
my @array = <FILE>;  # no need to use memory that way
                     # a lot of the input line will be
                     # thrown away
close(FILE);

##</code><code>##

open(FILE, "<", "x.log") or die "unable to open x.log $!";
while my $line (<FILE>)
{
   ... process each $line...

}