splitLetters.nf

#!/usr/bin/env nextflow
/*
 * Copyright 2013-2024, Seqera Labs
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

params.str = 'Hello world!'

process splitLetters {

    output:
    file 'chunk_*'

    """
    printf '${params.str}' | split -b 6 - chunk_
    """
}

process massage {

    input:
    file x

    output:
    stdout

    """
    cat $x | tr '[a-z]' '[A-Z]'
    """
}

workflow {
  splitLetters \
  | flatten \
  | massage \
  | view { it.trim() }
}