bash help

Bash scripting

1. Help option in bash script

#!/bin/bash

USAGE="my-script — does one thing well
  
  Usage:
    my-script <input> <output>
  
  Options:
    <input>   Input file to read.
    <output>  Output file to write. Use '-' for stdout.
    -h        Show this message.
"

  help() {
    echo "$USAGE"
  }

#if [[ $# = 0 ]] || [[ "$1" = "-h" ]]; then
if [[ "$1" = "-h" ]]; then
    help
    exit 1
fi