You can do this without modules. This is almost straight from the Perl Cookbook 7.10 Modifying a File in Place Without a Temporary File.

open(F, "+< $infile") or die "Can't read $infile: $!\n";
$out= '';
while (<F>) {
    #find the line you want and manipulate here
    $out .= $_;
}
seek(F, 0, 0) or die "Can't seek to start of $infile: $!\n";
print F $out or die "Can't print to $infile: $!\n";
truncate(F, tell(F)) or die "Can't truncate $infile: $!\n";
close(F) or die "Can't close $infile $!\n";
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-THRAK
www.polarlava.com