Determine which function called the current function in PHP

function_caller_in_php.md

To do this we can use debug_backtrace:

// $backtrace = debug_backtrace();
$backtrace = debug_backtrace(DEBUG_BACKTRACE_IGNORE_ARGS, 2);

// $caller = isset($backtrace[1]['function']) ? $backtrace[1]['function'] : 'unknown';
$caller = $backtrace[1]['function'] ?? 'unknown';

The caller is at index 1 (index 0 is the current function).

If we only need the function name, use debug_backtrace(DEBUG_BACKTRACE_IGNORE_ARGS, 2) to limit the backtrace depth and ignore arguments for better performance.

If called from a class method, then we can also find out the class

$class = $backtrace[1]['class'] ?? 'unknown';