Question

In BASH, is it possible to get the function name in function body? Taking following codes as example, I want to print the function name “Test” in its body, but “$0” seems to refer to the script name instead of the function name. So how to get the function name?

#!/bin/bash

function Test
{
    if [ $# -lt 1 ]
    then
        #   how to get the function name here?
        echo "$0 num" 1>&2
        exit 1
    fi
    local num="${1}"
    echo "${num}"
}

#   the correct function
Test 100

#   missing argument, the function should exit with error
Test

exit 0

Answer 1

Try ${FUNCNAME[0]}. This array contains the current call stack. To quote the man page:

   FUNCNAME
          An  array  variable  containing the names of all shell functions
          currently in the execution call stack.  The element with index 0
          is the name of any currently-executing shell function.  The bot‐
          tom-most element is "main".  This variable exists  only  when  a
          shell  function  is  executing.  Assignments to FUNCNAME have no
          effect and return an error status.  If  FUNCNAME  is  unset,  it
          loses its special properties, even if it is subsequently reset.