my $count = 0;
my $seqlinec = 2;
while ( <INFILE> ) {
    if ( $seqlinc eq $count ) {
        print "$_\n";
    }
    $seqlinec += 4;
}

[download]

I assume you want to somehow count the line you are reading. In that case, you should increment your counter somewhere. Maybe do something like the following (untested!) code

my $count = 0;
while ( <INFILE> ) {
    next        if ( !$count++ );   # ignore line zero, increase linec
+ount
    print $_;
    $count = 0  if ($count >= 3);   # reset the counter once we printe
+d line 3 
}

[download]

HTH, Rata

note: of course the code could be easily optimized, e.g. by using ($count++ % 4); see Boolean counter? for some ways (you need to adapt them to count modulo 4)

In reply to Re: Getting Lines 2,3, and 4 from FASTQ file's Chunk by Ratazong
in thread Getting Lines 2,3, and 4 from FASTQ file's Chunk by neversaint

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