getopts

getopts

In Linux, the getopts function is used to parse command-line options. It is a built-in function that is available in most shells.

The optstring argument is a string that specifies the options that you want to parse. The var argument is the name of the variable that will store the parsed options.

For example, the following code will parse the options -a, -b, and -c:

while getopts ":abc" opt; do
  case $opt in
    a)
      echo "Option -a was specified."
      ;;
    b)
      echo "Option -b was specified."
      ;;
    c)
      echo "Option -c was specified."
      ;;
    *)
      echo "Unknown option: $opt"
      ;;
  esac
done

help

Options:

-n, --no-argument   Don't assign an argument to the option.
-r, --require-argument   The option must have an argument.
-u, --uppercase   Use uppercase letters for the option names.

breakdown

The : character indicates that the option takes an argument.
The - character indicates that the option is optional.
The a, b, and c characters are the names of the options.