Pasted

#!/usr/bin/env bash
 
###
# Prints the index number, followed by the value of the file's first
# line. This means that CSV's with headers create a nice list and CSV
# files without headers are easier to flesh out.
###
 
main() { 
  local file
  file=$(check_args "$@")
 
  [[ $file == "1" ]] \
      && echo "Could not find input file, or file does not exist" \
      && exit 1
 
  csv_header=$(head -n 1 "${1}")
  IFS=',' read -r -a array <<< "$csv_header"
 
  for index in "${!array[@]}"; do
    printf "%s\t%s\n" "$index" "${array[index]}"
  done
}
 
 
check_args() {
    [[ ! -z $1 ]] && [[ -f "$1" ]] && echo "0" || echo "1"
}
 
main "$@"