PHP DEBUG_TRACE

 <?php

function a($txt) {

  b("Glenn");

}

function b($txt) {

  c("Cleveland");

}

function c($txt) {

  echo '<pre>', var_dump(debug_backtrace());

}

a("Peter");

?>

array(3) {
  [0]=>
  array(4) {
    ["file"]=>
    string(21) "/home/Xx8WIO/prog.php"
    ["line"]=>
    int(10)
    ["function"]=>
    string(1) "c"
    ["args"]=>
    array(1) {
      [0]=>
      string(9) "Cleveland"
    }
  }
  [1]=>
  array(4) {
    ["file"]=>
    string(21) "/home/Xx8WIO/prog.php"
    ["line"]=>
    int(7)
    ["function"]=>
    string(1) "b"
    ["args"]=>
    array(1) {
      [0]=>
      string(5) "Glenn"
    }
  }
  [2]=>
  array(4) {
    ["file"]=>
    string(21) "/home/Xx8WIO/prog.php"
    ["line"]=>
    int(15)
    ["function"]=>
    string(1) "a"
    ["args"]=>
    array(1) {
      [0]=>
      string(5) "Peter"
    }
  }
}

The debug_backtrace() function generates a PHP backtrace.
This function displays data from the code that led up to the debug_backtrace() function.
Returns an array of associative arrays. The possible returned elements are:

https://www.w3schools.com/php/func_error_debug_backtrace.asp