lh3/seqtk — pull request #20 by brentp (2013-12-27 22:23:05+00:00)
Title: support trimming of paired end reads by interleave -> trim -> re-pair

This set of commits allows something like:

```shell

./seqtk interleave R1.fastq R2.fastq \
| ./seqtk trimfq - \
| ./seqtk pairfq -

```

So that the existing machinery can be used to trim paired-end fastq files. Or **any single-end trim command can be used in place of `seqtk trimfq`**

This can be checked by appending this to the end:

| awk 'NR % 4 == 1 { print $1 }' | uniq -c | awk '$1 != 2'

which should give empty output when all reads are paired.

It would be nice of the cpy_kseq command was included in kseq.h