SEQanswers - perl script to filter errors in fastq files?

Perl script to do some sanity checks on fastq files. 

good to check if they were corrupted via FTP transfer. 

credit: Simon Andrews

http://seqanswers.com/forums/showpost.php?p=29075&postcount=8

  #!/usr/bin/perl use warnings; use strict;  while (<>) {    unless (/^\@/) {     warn "$_ should have had an \@ at the start and it didn't\n";     next;   }   my $id1 = $_;   my $seq = <>;   my $id2 = <>;   my $qual = <>;    if ($seq =~/^[@+]/) {     warn "Sequence '$seq' looked like an id";     next;   }   if ($qual =~/^[@+]/) {     warn "Quality '$qual' looked like an id";     next;   }   if ($id2 !~ /^\+/) {     warn "Midline '$id2' didn't start with a +";     next;   }    if ($qual =~ /[GATCN]{20,}/) {     warn "Quality '$qual' looked like sequence";     next;   }    if (length($seq) != length($qual)) {     warn "Seq $seq and Qual $qual weren't the same length";     next;   }    print $id1,$seq,$id2,$qual;   }