How to get name of calling function/method in PHP? [duplicate]

Asked 21/1, 2010 at 16:10 Answered 19/2, 2015 at 9:2

Solved php debugging backtrace method-call

301

I am aware of function debug_backtrace, but I am looking for some ready to use implementation of function like GetCallingMethodName()? It would be perfect if it gave method's class too (if it is indeed a method).

Hildegardhildegarde answered 21/1, 2010 at 16:10 Comment(1)

Ah, yet another example where a question or bug report with the superior answer or report is marked as a duplicate of an earlier though inferior posting. I'll have to fix that problem in the industry too. – Uriah 20/5, 2018 at 0:1

171

The debug_backtrace() function is the only way to know this, if you're lazy it's one more reason you should code the GetCallingMethodName() yourself. Fight the laziness! :D

Hammerlock answered 21/1, 2010 at 16:13 Comment(5)

"Fight the laziness! :D" But laziness is a good thing: codinghorror.com/blog/archives/000237.html :} So if someone has written such a function, I would really appreciate... :} – Hildegardhildegarde 21/1, 2010 at 16:37

Who needs google while having such a great 'programming answers search engine' as stackoverflow users like You :} https://mcmap.net/q/101743/-get-name-of-caller-function-in-php/… Now seriously, thanks! – Hildegardhildegarde 21/1, 2010 at 18:44

For Better performance pass these args, debug_backtrace(DEBUG_BACKTRACE_IGNORE_ARGS, 2) . – Ethnarch 15/11, 2016 at 10:59

Thanks. Manual link for reference php.net/manual/en/function.debug-backtrace.php – Blender 24/8, 2017 at 13:38

It is not about laziness - if the programmer is paid for the solution, it is perfectly valid trying not to reinvent the wheel. – Inerrable 17/4, 2019 at 14:3

678

The simplest way is:

echo debug_backtrace()[1]['function'];

As noted in the comments below, this can be further optimized by passing arguments to:

omit both the object and args indices
limit the number of stack frames returned

echo debug_backtrace(!DEBUG_BACKTRACE_PROVIDE_OBJECT|DEBUG_BACKTRACE_IGNORE_ARGS,2)[1]['function'];

Paneling answered 28/6, 2012 at 4:24 Comment(16)

Why was this not marked as the correct answer? – Plimsoll 12/1, 2016 at 15:37

Yes, this is the correct answer. I keep coming back and referring to it every time I need it. – Ian 7/4, 2016 at 13:29

Just found this. Very useful BUT it's worth noting that there could be a major overhead involved here. I ran print_r(debug_backtrace()) and it basically crashed my browser with the weight of info it returned. – Laborer 22/7, 2016 at 11:41

since 5.4 you can pass a second parameter to limit the number of entries. – Narah 10/8, 2016 at 18:28

If your browser crashed trying to print debug_backtrace(), you probably have other, more serious issues. Either you're passing huge objects as parameters, or your call-stack is enormously deep, or you're using a pretty dodgy browser! – Arathorn 6/9, 2016 at 12:39

It supposed to be the first element: debug_backtrace()[0]['function'] – Wey 30/11, 2017 at 21:41

It's worth optimizing this a little bit: debug_backtrace(DEBUG_BACKTRACE_IGNORE_ARGS,2)[1]['function'] – Saritasarkaria 15/5, 2018 at 5:52

It's not marked as the correct answer because it has been given two years after the former one, but it indeed remains the most relevant. – Strongwilled 8/6, 2018 at 13:52

I'd upvote twice ! – Solder 27/10, 2019 at 18:15

Note: this only works since PHP 5.4 – Marplot 15/4, 2020 at 12:8

If all you truly need is the function name, you could further refine the bitmask to !DEBUG_BACKTRACE_PROVIDE_OBJECT|DEBUG_BACKTRACE_IGNORE_ARGS – Caudex 12/1, 2021 at 10:3

@parttimeturtle: did you mean ^ instead of !? – Lohse 6/6, 2022 at 18:29

@BenoitDuffez I did not. DEBUG_BACKTRACE_PROVIDE_OBJECT is just an integer constant with a value of 1, indicating you want the object field populated. Negating that just gives you 0 to indicate the contrary. You don't want to XOR the two constants, you want to negate the first. – Caudex 6/6, 2022 at 18:58

! is boolean negation, not binary negation. I actually meant ~, not ^. Negating 1 does not do anything, you could negate 2 or 1000 it would still give 0. I think the proper negation would be ~DEBUG_BACKTRACE_PROVIDE_OBJECT. – Lohse 14/6, 2022 at 17:47

For example, if you want to negate everything but constant 1, and 2 (implying for example activation of 4), you would do ~1|2 and not !1|2. Test: $ php -r 'printf("val=%d lneg=%d bneg=%d lcheck=%d ncheck=%d\n", 1|2, !1|2, ~1|2, (!1|2) & 4, (~1|2) & 4);' prints val=3 lneg=2 bneg=-2 lcheck=0 ncheck=4. The 1st check (logical) fails which is not the intent, and the 2nd check (binary) passes which is the intent. – Lohse 14/6, 2022 at 17:55

I'm getting inconsistent behaviour when using tools like ioncode to encrypt your code base. In my case it was not discovering Laravel's BelongsTo relationships in random cases. – Gev 26/1, 2023 at 11:57

171

The debug_backtrace() function is the only way to know this, if you're lazy it's one more reason you should code the GetCallingMethodName() yourself. Fight the laziness! :D

Hammerlock answered 21/1, 2010 at 16:13 Comment(5)

For Better performance pass these args, debug_backtrace(DEBUG_BACKTRACE_IGNORE_ARGS, 2) . – Ethnarch 15/11, 2016 at 10:59

Thanks. Manual link for reference php.net/manual/en/function.debug-backtrace.php – Blender 24/8, 2017 at 13:38

It is not about laziness - if the programmer is paid for the solution, it is perfectly valid trying not to reinvent the wheel. – Inerrable 17/4, 2019 at 14:3

As of php 5.4 you can use

        $dbt=debug_backtrace(DEBUG_BACKTRACE_IGNORE_ARGS,2);
        $caller = isset($dbt[1]['function']) ? $dbt[1]['function'] : null;

This will not waste memory as it ignores arguments and returns only the last 2 backtrace stack entries, and will not generate notices as other answers here.

Pottle answered 19/2, 2015 at 9:2 Comment(6)

@Krzysztof Trzos Try echo $caller; and should work. ;-) – Matroclinous 10/2, 2016 at 21:47

This should be the accepted answer. – Irregular 27/12, 2016 at 10:22

I confirm it is working for for php 5.6 – Skeleton 28/2, 2018 at 4:52

As of PHP 7 the 2nd line can be $caller = $dbt[1]['function'] ?? null; – Lepidopteran 19/12, 2019 at 21:59

Note that isset($something) ? $something : null can be shortened to $something ?? null in modern PHP versions. Edit: sorry, someone already covered this – Commendam 15/5, 2020 at 4:32

or one line debug_backtrace(DEBUG_BACKTRACE_IGNORE_ARGS,2)[1]['function'] ?? null; – Objectivism 14/10, 2020 at 13:59

You can also use the info provided by a php exception, it's an elegant solution:


function GetCallingMethodName(){
    $e = new Exception();
    $trace = $e->getTrace();
    //position 0 would be the line that called this function so we ignore it
    $last_call = $trace[1];
    print_r($last_call);
}

function firstCall($a, $b){
    theCall($a, $b);
}

function theCall($a, $b){
    GetCallingMethodName();
}

firstCall('lucia', 'php');

And you get this... (voilà!)

Array
(
    [file] => /home/lufigueroa/Desktop/test.php
    [line] => 12
    [function] => theCall
    [args] => Array
        (
            [0] => lucia
            [1] => php
        )

)

Silvester answered 3/2, 2012 at 18:50 Comment(4)

Interesting approach and I kind of like it but why is it better than using debug_backtrace? – Boatsman 23/6, 2012 at 19:13

Be aware, I did a quick benchmarks and looks like this solution is 2x times slower than the debug_backtrace(). However, we are talking about micro-optimization untill you dont use this method very often in your code – Kielty 22/8, 2012 at 9:34

Yes, debug_backtrace is the right solution, but if you tend to forget the name of the functions, create an exception and print its trace might be easier to remember. In my case I use this only for code debugging, I haven't left it on production for any reason. If I wanted to build a debugging/logging system I would use debug_backtrace. – Silvester 26/1, 2015 at 18:59

If I call the GetCallingMethodName() function within the "theCall()", then I would expect "firstCall()" as caller function and not the function itself. Setting $last_call = $trace[2]; in GetCallingMethodName() solves the problem. – Oxygen 5/8, 2015 at 12:44

For me debug_backtrace was hitting my memory limit, and I wanted to use this in production to log and email errors as they happen.

Instead I found this solution which works brilliantly!

// Make a new exception at the point you want to trace, and trace it!
$e = new Exception;
var_dump($e->getTraceAsString());

// Outputs the following 
#2 /usr/share/php/PHPUnit/Framework/TestCase.php(626): SeriesHelperTest->setUp()
#3 /usr/share/php/PHPUnit/Framework/TestResult.php(666): PHPUnit_Framework_TestCase->runBare()
#4 /usr/share/php/PHPUnit/Framework/TestCase.php(576): PHPUnit_Framework_TestResult->run(Object(SeriesHelperTest))
#5 /usr/share/php/PHPUnit/Framework/TestSuite.php(757): PHPUnit_Framework_TestCase->run(Object(PHPUnit_Framework_TestResult))
#6 /usr/share/php/PHPUnit/Framework/TestSuite.php(733): PHPUnit_Framework_TestSuite->runTest(Object(SeriesHelperTest), Object(PHPUnit_Framework_TestResult))
#7 /usr/share/php/PHPUnit/TextUI/TestRunner.php(305): PHPUnit_Framework_TestSuite->run(Object(PHPUnit_Framework_TestResult), false, Array, Array, false)
#8 /usr/share/php/PHPUnit/TextUI/Command.php(188): PHPUnit_TextUI_TestRunner->doRun(Object(PHPUnit_Framework_TestSuite), Array)
#9 /usr/share/php/PHPUnit/TextUI/Command.php(129): PHPUnit_TextUI_Command->run(Array, true)
#10 /usr/bin/phpunit(53): PHPUnit_TextUI_Command::main()
#11 {main}"

Splendor answered 27/2, 2014 at 10:53 Comment(3)

nice find, this is pure GOLD. – Promptbook 9/5, 2019 at 2:16

This is perfect for my scenario. Thank you. – Holmgren 20/4, 2021 at 11:44

nice work around – Stereotypy 18/10, 2021 at 13:4

My favourite way, in one line!

debug_backtrace()[1]['function'];

You can use it like this:

echo 'The calling function: ' . debug_backtrace()[1]['function'];

Note that this is only compatible with versions of PHP released within the last year. But it's a good idea to keep your PHP up to date anyway for security reasons.

Seraphic answered 11/10, 2014 at 20:10 Comment(4)

This method has been provided countless times already, and a problem is that it will only work on PHP 5.4 or higher. – Marciemarcile 12/10, 2014 at 0:43

lol thanks @ialarmedalien :D As for compatibility, I'm perhaps too aggressive with updates? I feel people should keep their PHP (reasonably) up to date. It's free, and a security risk to use outdated software. When you're using 2 or 3 year old versions of PHP, you're not just losing out on nice features like this, you're also putting your server at risk. – Seraphic 12/10, 2014 at 18:53

@Seraphic That comment demonstrates a lack of understanding of how PHP and most popular tools are maintained. PHP 5.3 continued to receive updates for security issues for years after the release of PHP 5.4. Just being an an old version of PHP does not mean you are necessarily on an insecure PHP. – Multiform 3/2, 2016 at 22:8

@meagar Any version of PHP that doesn't support this method is below version 5.4. Which hasn't been supported or updated since 2015. So yes, it's a security risk to not upgrade. (php.net/eol.php) – Seraphic 23/4, 2018 at 20:47

I just wrote a version of this called "get_caller", I hope it helps. Mine is pretty lazy. You can just run get_caller() from a function, you don't have to specify it like this:

get_caller(__FUNCTION__);

Here's the script in full with a quirky test case:

<?php

/* This function will return the name string of the function that called $function. To return the
    caller of your function, either call get_caller(), or get_caller(__FUNCTION__).
*/
function get_caller($function = NULL, $use_stack = NULL) {
    if ( is_array($use_stack) ) {
        // If a function stack has been provided, used that.
        $stack = $use_stack;
    } else {
        // Otherwise create a fresh one.
        $stack = debug_backtrace();
        echo "\nPrintout of Function Stack: \n\n";
        print_r($stack);
        echo "\n";
    }

    if ($function == NULL) {
        // We need $function to be a function name to retrieve its caller. If it is omitted, then
        // we need to first find what function called get_caller(), and substitute that as the
        // default $function. Remember that invoking get_caller() recursively will add another
        // instance of it to the function stack, so tell get_caller() to use the current stack.
        $function = get_caller(__FUNCTION__, $stack);
    }

    if ( is_string($function) && $function != "" ) {
        // If we are given a function name as a string, go through the function stack and find
        // it's caller.
        for ($i = 0; $i < count($stack); $i++) {
            $curr_function = $stack[$i];
            // Make sure that a caller exists, a function being called within the main script
            // won't have a caller.
            if ( $curr_function["function"] == $function && ($i + 1) < count($stack) ) {
                return $stack[$i + 1]["function"];
            }
        }
    }

    // At this stage, no caller has been found, bummer.
    return "";
}

// TEST CASE

function woman() {
    $caller = get_caller(); // No need for get_caller(__FUNCTION__) here
    if ($caller != "") {
        echo $caller , "() called " , __FUNCTION__ , "(). No surprises there.\n";
    } else {
        echo "no-one called ", __FUNCTION__, "()\n";
    }
}

function man() {
    // Call the woman.
    woman();
}

// Don't keep him waiting
man();

// Try this to see what happens when there is no caller (function called from main script)
//woman();

?>

man() calls woman(), who calls get_caller(). get_caller() doesn't know who called it yet, because the woman() was cautious and didn't tell it, so it recurses to find out. Then it returns who called woman(). And the printout in source-code mode in a browser shows the function stack:

Printout of Function Stack: 

Array
(
    [0] => Array
        (
            [file] => /Users/Aram/Development/Web/php/examples/get_caller.php
            [line] => 46
            [function] => get_caller
            [args] => Array
                (
                )

        )

    [1] => Array
        (
            [file] => /Users/Aram/Development/Web/php/examples/get_caller.php
            [line] => 56
            [function] => woman
            [args] => Array
                (
                )

        )

    [2] => Array
        (
            [file] => /Users/Aram/Development/Web/php/examples/get_caller.php
            [line] => 60
            [function] => man
            [args] => Array
                (
                )

        )

)

man() called woman(). No surprises there.

Antioch answered 22/1, 2011 at 12:17 Comment(2)

also, you can call get_caller(someFunctionName) for any name in the stack at the time. So if wife() called man(), and man() called woman(), you could find out who called man() in woman() and hang up. – Antioch 22/1, 2011 at 13:25

It's nice, thank you – Soledadsolely 15/1, 2022 at 12:35

I needed something to just list the calling classes/methods (working on a Magento project).

While debug_backtrace provides tons of useful information, the amount of information it spewed out for the Magento installation was overwhelming (over 82,000 lines!) Since I was only concerned with the calling function and class, I worked this little solution up:

$callers = debug_backtrace();
foreach( $callers as $call ) {
    echo "<br>" . $call['class'] . '->' . $call['function'];
}

Observable answered 20/6, 2013 at 18:7 Comment(0)

The simplest way of getting parent function name is:

$caller = next(debug_backtrace())['function'];

Bonnybonnyclabber answered 23/5, 2014 at 11:15 Comment(1)

I like this, but it throws a notice in 7.4. PHP Notice: Only variables should be passed by reference - hard coding an array index feels tacky, but I guess if you want a one liner that's what you've got to do. – Kuo 25/5, 2021 at 14:52

Best answer of that question I've seen is:

list(, $caller) = debug_backtrace(false);

Short and clean

Stockholm answered 11/12, 2012 at 10:15 Comment(4)

debug_backtrace()[1]['function'] doesn't appeal? – Framework 11/7, 2013 at 19:47

@Framework That would only work in php >= 5.4. – Soosoochow 18/8, 2013 at 15:38

list($me, $caller) = debug_backtrace(false); echo $caller['function']; works in PHP >=5.0 and also in PHP 7.x – Govan 5/1, 2018 at 16:27

@fyrye list(, $caller) is perfectly valid php; the manual states: "list() constructs can no longer be empty." That construct is not empty. What is not valid about this answer from 2012--as of php 5.3.6 the method signature is debug_backtrace(int $options) and does not accept false. – Culliton 19/8, 2019 at 16:29

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