Merging separate sequence and quality files to FASTQ

#!/usr/bin/perl -w

use strict;

use Bio::SeqIO;
use Bio::Seq::Quality;

use Getopt::Long;

die "pass a fasta and a fasta-quality file\n"
  unless @ARGV;

my ($seq_infile,$qual_infile)
  = (scalar @ARGV == 1) ?($ARGV[0], "$ARGV[0].qual") : @ARGV;

## Create input objects for both a seq (fasta) and qual file

my $in_seq_obj =
  Bio::SeqIO->new( -file   => $seq_infile,
		   -format => 'fasta',
		 );

my $in_qual_obj =
  Bio::SeqIO->new( -file   => $qual_infile,
		   -format => 'qual',
		 );

my $out_fastq_obj =
  Bio::SeqIO->new( -format => 'fastq'
		 );

while (1){
  ## create objects for both a seq and its associated qual
  my $seq_obj  = $in_seq_obj->next_seq || last;
  my $qual_obj = $in_qual_obj->next_seq;

  die "foo!\n"
    unless
      $seq_obj->id eq
	$qual_obj->id;

  ## Here we use seq and qual object methods feed info for new BSQ
  ## object.
  my $bsq_obj =
    Bio::Seq::Quality->
	new( -id   => $seq_obj->id,
	     -seq  => $seq_obj->seq,
	     -qual => $qual_obj->qual,
	   );

  ## and print it out.
  $out_fastq_obj->write_fastq($bsq_obj);
}