params.fastq = "$baseDir/data/fastq/*.fastq" log.info "fastq files : ${params.fastq}" Channel .fromPath( params.fastq ) .ifEmpty { error "Cannot find any fastq files matching: ${params.fastq}" } .map { it -> [(it.baseName =~ /([^\.]*)/)[0][1], it]} .set { fastq_files } process trimming { tag "$file_id" echo true input: set file_id, file(reads) from fastq_files output: set file_id, "*_trim.fastq.gz" into fastq_files_trim script: """ UrQt --t 20 --m ${task.cpus} --gz \ --in ${reads} \ --out ${file_id}_trim.fastq.gz \ > ${file_id}_trimming_report.txt """ }