PHP में Current Function Name प्राप्त करना

PHP में currently executing function/method का नाम प्राप्त करने के magic constants।

Magic Constants

Basic Usage

<?php
function myFunction() {
    echo __FUNCTION__; // myFunction
}

class MyClass {
    public function myMethod() {
        echo __METHOD__; // MyClass::myMethod
        echo __FUNCTION__; // myMethod (only method name)
    }
    
    public static function staticMethod() {
        echo __METHOD__; // MyClass::staticMethod
    }
}

myFunction();
$obj = new MyClass();
$obj->myMethod();
MyClass::staticMethod();

Inheritance के साथ व्यवहार

<?php
class Base {
    public function display() {
        echo "__FUNCTION__: " . __FUNCTION__ . "\n"; // display
        echo "__METHOD__: " . __METHOD__ . "\n";     // Base::display
        echo "__CLASS__: " . __CLASS__ . "\n";       // Base
    }
}

class Derived extends Base {
    public function display() {
        echo "__FUNCTION__: " . __FUNCTION__ . "\n"; // display
        echo "__METHOD__: " . __METHOD__ . "\n";     // Derived::display (actual called class!)
        echo "__CLASS__: " . __CLASS__ . "\n";       // Derived
    }
}

$base = new Base();
$base->display();

echo "---\n";

$derived = new Derived();
$derived->display();

Anonymous Functions / Closures

<?php
$closure = function() {
    echo __FUNCTION__; // {closure}
};

$arrowFn = fn() => __FUNCTION__; // {closure}

$closure();
$arrowFn();

Trait में

<?php
trait Logger {
    public function log($msg) {
        echo "[" . __TRAIT__ . "::" . __FUNCTION__ . "] $msg\n";
    }
}

class Service {
    use Logger;
}

$svc = new Service();
$svc->log('Starting...'); // [Logger::log] Starting...

Debug Backtrace (Caller Info)

<?php
function getCallerInfo() {
    $trace = debug_backtrace(DEBUG_BACKTRACE_IGNORE_ARGS, 2);
    // [0] = getCallerInfo, [1] = caller
    
    if (isset($trace[1])) {
        $caller = $trace[1];
        return [
            'function' => $caller['function'] ?? 'unknown',
            'class' => $caller['class'] ?? null,
            'file' => $caller['file'] ?? 'unknown',
            'line' => $caller['line'] ?? 0,
        ];
    }
    return null;
}

function outer() {
    inner();
}

function inner() {
    $info = getCallerInfo();
    print_r($info);
    // Array ( [function] => outer [class] => [file] => ... [line] => ... )
}

outer();

Practical: Logging Helper

<?php
function debugLog($message, $context = []) {
    $trace = debug_backtrace(DEBUG_BACKTRACE_IGNORE_ARGS, 2);
    $caller = $trace[1] ?? [];
    
    $log = [
        'time' => date('c'),
        'function' => $caller['function'] ?? 'global',
        'class' => $caller['class'] ?? '',
        'file' => basename($caller['file'] ?? ''),
        'line' => $caller['line'] ?? 0,
        'message' => $message,
        'context' => $context
    ];
    
    error_log(json_encode($log, JSON_UNESCAPED_UNICODE));
}

// उपयोग
class UserService {
    public function createUser($data) {
        debugLog('Creating user', ['email' => $data['email']]);
        // ...
    }
}