task sample { File sequenceFile String? outFilePath = "subsampledReads.fq.gz" String? preCommand Int? seed Boolean? twoPassMode Float? fraction Int? number Boolean? zip = true command { set -e -o pipefail ${'mkdir -p $(dirname ' + outFilePath + ')'} ${preCommand} seqtk sample \ ${"-s " + seed} \ ${true="-2 " false="" twoPassMode} \ ${sequenceFile} \ ${number} ${fraction} \ ${true="| gzip" false="" zip} \ ${"> " + outFilePath} } output { File subsampledReads= select_first([outFilePath]) } }