dynamic-filename.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.prefix = 'my'

data = 'Hello\n'
list = ['alpha', 'delta', 'gamma', 'omega']

process foo {

  input:
  each x
  file "${params.prefix}_${x}.txt"

  output:
  file "${params.prefix}_${x}.txt"

  """
  echo World >>  ${params.prefix}_${x}.txt
  """

}

workflow {
  foo(list, data) | subscribe { println "~ Saving ${it.name}"; it.copyTo('.') }
}