Is it possible to get the function name in function body?

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

score 91 · Accepted Answer · answered Feb 05 '12 at 03:18

91

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.

answered Feb 05 '12 at 03:18

FatalError

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1

Thanks, this really helps. I learn more than just the solution of my question. This array could be used to print the callstack when the script fails. – Yun Huang Feb 05 '12 at 03:33
5

Sure. In that regard, you might also find the contents of `BASH_LINENO` to be of interest. – FatalError Feb 05 '12 at 03:35
1

Or you can use the shorter and equivalent $FUNCNAME. – Guillem Jover Oct 06 '17 at 16:34

score 35 · Answer 2 · answered Feb 05 '12 at 03:17

The name of the function is in ${FUNCNAME[ 0 ]} FUNCNAME is an array containing all the names of the functions in the call stack, so:

$ ./sample
foo
bar
$ cat sample
#!/bin/bash

foo() {
        echo ${FUNCNAME[ 0 ]}  # prints 'foo'
        echo ${FUNCNAME[ 1 ]}  # prints 'bar'
}
bar() { foo; }
bar

Is it possible to get the function name in function body?

2 Answers2

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