LANGUAGE » SHELL_SCRIPT » BASH

Argument

Last updated:

Manual ​

shell
## Check the number of arguments
if [[ "$#" -ne 2 ]]; then
  # >&2 Echo output to standard error instead of standard out
  echo "Usage: $0 arg1 arg2" >&2
  exit 1
fi

echo $@  # All arguments
echo $1  # Argument 1
echo $2  # Argument 2

Checking existence of argument:

shell
if [[ "$*" == *' --argument'* ]]; then
  echo '--argument found'
fi

Getopts ​

Works for arguments with a single letter.

Nice tutorial here.

shell
while getopts ":a:" opt; do
  case ${opt} in
    a)
      echo "-a was triggered, Parameter: ${OPTARG}"
      ;;
    \?)
      echo "Invalid option: -${OPTARG}" >&2
      exit 1
      ;;
    :)
      echo "Option -${OPTARG} requires an argument." >&2
      exit 1
      ;;
  esac
done