Bio::Index::Fastq(3) Interface for indexing (multiple) fastq files


# Complete code for making an index for several
# fastq files
use Bio::Index::Fastq;
use strict;
my $Index_File_Name = shift;
my $inx = Bio::Index::Fastq->new(
'-filename' => $Index_File_Name,
'-write_flag' => 1);
# Print out several sequences present in the index
# in Fastq format
use Bio::Index::Fastq;
use strict;
my $Index_File_Name = shift;
my $inx = Bio::Index::Fastq->new('-filename' => $Index_File_Name);
my $out = Bio::SeqIO->new('-format' => 'Fastq','-fh' => \*STDOUT);
foreach my $id (@ARGV) {
my $seq = $inx->fetch($id); # Returns Bio::Seq::Quality object
# or, alternatively
my $id;
my $seq = $inx->get_Seq_by_id($id); #identical to fetch


Inherits functions for managing dbm files from, and provides the basic funtionallity for indexing fastq files, and retrieving the sequence from them. Note: for best results 'use strict'.

Bio::Index::Fastq supports the Bio::DB::BioSeqI interface, meaning it can be used as a Sequence database for other parts of bioperl


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Please direct usage questions or support issues to the mailing list:

[email protected]

rather than to the module maintainer directly. Many experienced and reponsive experts will be able look at the problem and quickly address it. Please include a thorough description of the problem with code and data examples if at all possible.

Reporting Bugs

Report bugs to the Bioperl bug tracking system to help us keep track the bugs and their resolution. Bug reports can be submitted via the web:

AUTHOR - Tony Cox

Email - [email protected]


The rest of the documentation details each of the object methods. Internal methods are usually preceded with a _


 Title   : _file_format
 Function: The file format for this package, which is needed
           by the SeqIO system when reading the sequence.
 Returns : 'Fastq'


  Title   : _index_file
  Usage   : $index->_index_file( $file_name, $i )
  Function: Specialist function to index FASTQ format files.
            Is provided with a filename and an integer
            by make_index in its SUPER class.
  Example : 
  Returns : 
  Args    :


  Title   : id_parser
  Usage   : $index->id_parser( CODE )
  Function: Stores or returns the code used by record_id to
            parse the ID for record from a string.  Useful
            for (for instance) specifying a different
            parser for different flavours of FASTQ file. 
            Returns \&default_id_parser (see below) if not
            set. If you supply your own id_parser
            subroutine, then it should expect a fastq
            description line.  An entry will be added to
            the index for each string in the list returned.
  Example : $index->id_parser( \&my_id_parser )
  Returns : ref to CODE if called without arguments
  Args    : CODE


  Title   : default_id_parser
  Usage   : $id = default_id_parser( $header )
  Function: The default Fastq ID parser for
            Returns $1 from applying the regexp /^>\s*(\S+)/
            to $header.
  Returns : ID string
  Args    : a fastq header line string