Shell Programming and Scripting

$num = 0;

while ($num <= $#arr_y ) {
        open(FH,"< file2") or die $!;
        print "@LISTING[$num] is undercheck now.\n";
                while( <FH> ) {
                chomp;
                if($_ =~ @LISTING[$num] && $_ =~ @SLIST[$num]) {
                        $check_file = "already_appended"
                        }
                else
                {
                        $check_file = "not_yet_appended"
                };
                };
                print "$check_file \n";
                close FH;

                print "FILE ID PROCESSING IS @arr_y[$num]\n";
                if($check_file eq 'not_yet_appended') {
                        print "APPENDING\n";
                        $command = "myscript.pl @arr_y[$num] |";
                        my $pipe_des;
                        open($pipe_des, $command) or die "Unable to open pipe command : $command <$!> \n";
                        open(OUTPUT, ">> file2");
                        while (<$pipe_des>) {   # read a line of input from myscript.pl
                                print OUTPUT;   # print it to the output handle
                        }
                        close $pipe_des;
                        close OUTPUT;
                        print "@LISTING[$num] will be appended.\n"
                }
                else
                {
                        print "@LISTING[$num] will NOT be appended.\n";
                };
        $num = $num + 1;
        };
};