split.nf

process SPLIT {
    tag "$meta.id"
    label 'small_mem_mono_cpus'

    container "lbmc/alpine:3.17"

    input:
    tuple val(meta), path(fastq)

    output:
    tuple val(meta), path("*.fastq.gz"), emit: fastq
    path "versions.yml"           , emit: versions

    script:
    def args = task.ext.args ?: ''
    """
    zcat ${fastq} | split -l 4000000 - ${fastq.simpleName}_

    ls -l ${fastq.simpleName}_* | \\
        awk '{system("if [\$((wc -l "\$9")) -ne 4000000]; then exit 1; fi")}'

    ls -l ${fastq.simpleName}_* | \\
        awk '{system("gzip -c "\$9" > "\$9".fastq.gz && rm "\$9)}'

    cat <<-END_VERSIONS > versions.yml
    "${task.process}":
        split: v1.35.0
    END_VERSIONS
    """
}