function

Create a shell function named NAME.

WARNING:

The declaration of a function must always stand before its use!

Documentation

• function [EN] @ GNU Bash Reference Manual

• bash -c 'help function'
• man 1 'bash' [EN]

Syntax

function NAME {
  ...
}

NAME() {
  ...
}

Examples

Define and use a Bash function

nf::carp() {
  # Shows the exact position of an error, prints the error message and
  # optionally exits the script.
  # The name of this function was derived from the Perl module "Carp".
  #
  # Arguments:
  #   $1: Parameter '-e' with error number (optional)
  #   $@: Error message
  #
  # Returns:
  #   0:  Success
  #   >0: Error
  #
  # Example:
  #   nf::carp -e2 'Error running AppleScript!'

  # Print the runtime position of the script
  if ! nf::runtime_position 1; then
    return 1
  fi

  # If the first argument starts with '-e' followed by a number
  if [[ "$1" =~ ^-e([0-9]*)$ ]]; then
    # Prints the error message
    echo ": ${*:2}"

    # Exits the script
    exit "${BASH_REMATCH[1]:-1}"
  else
    # Prints the error message
    echo ": $*"
  fi

  return 0
} 1>&2

foo() {
  if [[ -z "${var}" ]]; then
    nf::carp 'Argument not available!'
    return 1
  fi
}

bar() {
  foo
}

# Test usage in functions
bar
foo

# Test usage directly in the script
if [[ ! -f "${file}" ]]; then
  nf::carp -e2 'Error finding file!'
fi

Output:

test.sh[49]>bar[45]>foo[39]: Argument not available!
test.sh[50]>foo[39]: Argument not available!
test.sh[54]: Error finding file!