1

This is my simplified script.

I am wondering if the proc() can know if it is run directly or through the runner.

#!/bin/bash
runner () {
    "${@}"
}
proc() {
    eval 'version=$(echo "SUCCESS: **** ${BASH_VERSION} ****")'
    echo -e "$version"; 
    return 0
}

runner proc
proc

What do you think?

3

proc is not a separate process in your example. It's just a function, run in the same process as the main shell.

The $FUNCNAME array gives it access to its backtrace:

foo(){ bar; }
bar(){ baz; }
baz(){ proc; }
proc(){ echo "${FUNCNAME[@]}"; }

$ foo
proc baz bar foo main

So yes, it can:

case ${FUNCNAME[1]} in runner) ...

If you experiment with it, you will see that running it in a subshell / subprocess doesn't break the backtrace or affect it in any way:

foo(){ (bar &) | cat; }
=> same output
  • true, I clarified my title. let me check what I can do with your info. thanks a bunch – conanDrum Jun 14 at 0:02
  • I've added an example test and a note about functions, backtraces & subprocesses – mosvy Jun 14 at 0:14
  • excellent mosvy thanks mate – conanDrum Jun 14 at 0:37
  • I tested with calling a function like this 'bash <filename> <function>' and like this 'runner bash <filename> <function>' and the function is oblivious to who is calling it, based on your suggestion. Any other suggestions in this case? – conanDrum Jun 14 at 6:35
  • The backtrace will not work through exec, ie. processes which start an external command. For that to work, Unix will have to be something like a Lisp Machine ;-) – mosvy Jun 14 at 6:42

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