Pasted

#!/usr/bin/env bash
 
# Assumes the CSV file has a proper header!
thisfile="$0"
 
main() {
  local csv_header grep_result
  
  check_args "$@"
  
  grep_result=$(grep -E "${1}" "${2}")
  IFS=',' read -r -a grepArray <<< "$grep_result"
 
  csv_header=$(head -n 1 "${2}")
  IFS=',' read -r -a headerArray <<< "$csv_header"
 
  for index in "${!headerArray[@]}"; do
    printf "%2s%50s%50s\\n" "$index" "${headerArray[index]}" "${grepArray[index]}"
  done
}
 
exit_help() {
    printf "%s\n" "Usage: $thisfile <search regex> <filename>"
    exit 1
}
 
check_args() {
  # Check if we have 2 args
  if [ "$#" -ne 2 ]; then
       exit_help
  fi
 
    # Check that argument 2 is an existing file..
  [[ ! -z $2 ]] && [[ -f "$2" ]] || exit_help
}
 
main "$@"