# Find lines starting with "_ and ending with ", and containing optional
# leading or trailing whitespace.
#
my $MAL = '^\s*"_.*"\s*$';

##</code><code>##

use strict;
use warnings;

my $out     = "Backup/backup.txt";
my $out2    = "nomatch.txt";
my $logfile = "log.txt";
my $MAL = '^\s*"_.*"\s*$';

open LOG,  "<", $logfile or die "Cannot open $logfile for read :$!";
open OUT,  ">$out" or die "Cannot open $out for write :$!";
open OUT2, ">$out2" or die "Cannot open $out2 for write :$!";

while ( <LOG> ) {
  if ( $_ =~ /$MAL/i ) {
    print OUT $_;
  } else {
    print OUT2 $_;
  }
}