Dump the list of filenames of all *.tar.xz files in the current directory into a text file (parallelized by xargs)

dump_tar_xz_contents.sh

#!/bin/bash

dump_tar_xz_contents() {
  total="$1"
  index="$2"
  file="$3"
  file_without_extension="$(basename "$file" .tar.xz)"
  echo "[START][$index/$total] $file"
  tar tf "$file" > "$file_without_extension.txt"
  echo "[END][$index/$total] $file"
}
export -f dump_tar_xz_contents
total_files="$(find . -type f -name '*.tar.xz' | wc -l)"
find . -type f -name '*.tar.xz' | awk '{print NR " " $0}' | xargs -I{} -P30 -- bash -c "dump_tar_xz_contents $total_files {}"