michiel ed thalent circle nl (2012-09-14 11:14:57)

__METHOD__ will return bother the method name, as the class and namespace name.

__FUNCTION__ will only return the method name.

<?php
namespace General;

class ArgumentValidation {

    public static function validateIntArguments() {
        echo __FUNCTION__ . "\n";
        echo __METHOD__ . "\n";
    }
}

ArgumentValidation::validateIntArguments(new ArgumentValidation);
?>

Will return:

validateIntArguments
General\ArgumentValidation::validateIntArguments

If you want to get a ReflectionMethod instance of your sattis method is to use __FUNCTION__.

$refl = new \ReflectionMethod(__CLASS__, __FUNCTION__);

Anonymous (2012-05-25 08:25:05)

A note about __FUNCTION__ and create_function():
If you use __FUNCTION__ inside the body of a function you create with create_function(), the __FUNCTION__ always evaluates to the string "__lambda_func" (even in different functions created by create_function()), not the function name that is returned by create_function().

tc0nn (2012-05-15 05:55:54)

Also worth noting, I use a extreme-logger when doing intense troubleshooting. It basically does a debug_backtrace and logs certain info. I noticed on some older PHP installs (<5) I had to prepend __FILE__ and __LINE__ with ''. just to force PHP output a string. Specifically I was loading those two in an array which were concat'd onto a log file eventually.
example:
if($a['debug']){$of->logger(array('file'=>__FILE__,'line'=>''.__LINE__,'data'=>$sql_data_array));}

david at thegallagher dot net (2012-02-22 01:19:08)

You cannot check if a magic constant is defined. This means there is no point in checking if __DIR__ is defined then defining it. `defined('__DIR__')` always returns false. Defining __DIR__ will silently fail in PHP 5.3+. This could cause compatibility issues if your script includes other scripts.

Here is proof:

<?php
echo (defined('__DIR__') ? '__DIR__ is defined' : '__DIR__ is NOT defined' . PHP_EOL);
echo (defined('__FILE__') ? '__FILE__ is defined' : '__FILE__ is NOT defined' . PHP_EOL);
echo (defined('PHP_VERSION') ? 'PHP_VERSION is defined' : 'PHP_VERSION is NOT defined') . PHP_EOL;
echo 'PHP Version: ' . PHP_VERSION . PHP_EOL;
?>

Output:
__DIR__ is NOT defined
__FILE__ is NOT defined
PHP_VERSION is defined
PHP Version: 5.3.6

Anonymous (2011-12-27 08:44:26)

Further clarification on the __TRAIT__ magic constant.

<?php
trait PeanutButter {
    function traitName() {echo __TRAIT__;}
}

trait PeanutButterAndJelly {
    use PeanutButter;
}

class Test {
    use PeanutButterAndJelly;
}

(new Test)->traitName(); //PeanutButter
?>

jrivero24 at yahoo dot es (2011-08-05 02:37:00)

When __DIR__ is not defined, prior 5.3.0:

<?php if ( !defined('__DIR__') ) define('__DIR__', dirname(__FILE__)); ?>

user9 at voloreport dot com (2011-07-10 12:33:40)

Note that __FILE__ has a quirk when used inside an eval() call. It will tack on something like "(80) : eval()'d code" (the number may change) on the end of the string at run-time. The workaround is:
$script = php_strip_whitespace('myprogram.php');
$script = str_replace('__FILE__',"preg_replace('@\(.*\(.*$@', '', __FILE__,1)",$script);
eval($script);

chris dot kistner at gmail dot com (2011-04-20 05:16:17)

There is no way to implement a backwards compatible __DIR__ in versions prior to 5.3.0.
The only thing that you can do is to perform a recursive search and replace to dirname(__FILE__):
find . -type f -print0 | xargs -0 sed -i 's/__DIR__/dirname(__FILE__)/'

Jamie (2011-03-02 13:13:28)

Note that as mentioned, __FILE__ resolves any aliases. Other real path information, such as $_SERVER["SCRIPT_FILENAME"], doesn't.
__FILE__ => /volume1/web/mysite/admin/inc/includeFile.inc.php
$_SERVER["SCRIPT_FILENAME"] => /var/services/web/mysite/admin/products.php
If you need to compare one with the other, use
realpath($_SERVER["SCRIPT_FILENAME"])

stefan at efectos dot nl (2010-11-08 05:58:35)

When __DIR__ is not defined, you can also use this workaround to generate it:

<?php
if(!defined('__DIR__')) {
    $iPos = strrpos(__FILE__, "/");
    define("__DIR__", substr(__FILE__, 0, $iPos) . "/");
}
?>

Keep in mind this sets __DIR__ to the directory you are running this snippet from.

madboyka at yahoo dot com (2010-09-10 07:37:43)

Since namespace were introduced, it would be nice to have a magic constant or function (like get_class()) which would return the class name without the namespaces.
On windows I used basename(__CLASS__). (LOL)

Anonymous (2010-08-08 03:39:02)

__DIR__ befor PHP 5.3.0

<?php
if (!defined('__DIR__')) {
  class __FILE_CLASS__ {
    function  __toString() {
      $X = debug_backtrace();
      return dirname($X[1]['file']);
    }
  }
  define('__DIR__', new __FILE_CLASS__);
}
?>

me at jamessocol dot com (2008-06-25 09:11:00)

We need an eighth magic constant, something along the lines of __STATIC__. This should return the name of the class from which a static method was called, regardless of where in the inheritance tree the method was defined.

PHP 5.3 has the new use of the static keyword which will help, but it isn't perfect. You still have to repeat yourself frequently.

For example, trying to implement Active Record:

<?php

// In PHP 5.3

class Model
{
    public static function find()
    {
        echo static::$class;
    }
}

class Product extends Model
{
    protected static $class = __CLASS__;
}

class User extends Model
{
    protected static $class = __CLASS__;
}

Product::find(); // "Product"
User::find(); // "User"

?>

<?php

// With __STATIC__ keyword. (Would be better.)

class Model
{
    public static function find()
    {
        echo __STATIC__;
    }
}

class Product extends Model {}

class User extends Model {}

Product::find(); // "Product"
User::find(); // "User"

?>

[EDITED : Use get_called_class()]

php at kennel17 dot co dot uk (2007-06-20 10:29:33)

Further to my previous note, the 'object' element of the array can be used to get the parent object.  So changing the get_class_static() function to the following will make the code behave as expected:

<?php
    function get_class_static() {
        $bt = debug_backtrace();
    
        if (isset($bt[1]['object']))
            return get_class($bt[1]['object']);
        else
            return $bt[1]['class'];
    }
?>

HOWEVER, it still fails when being called statically.  Changing the last two lines of my previous example to

<?php
  foo::printClassName();
  bar::printClassName();
?>

...still gives the same problematic result in PHP5, but in this case the 'object' property is not set, so that technique is unavailable.

php at kennel17 dot co dot uk (2007-06-20 09:12:11)

In response to stangelanda at gmail dot com, (who suggested a possible fix to get the actual class name of the object, when being called statically).

in PHP5, this fix no longer works.  

Here is some example code:

<?php

  function get_class_static() {
    $bt = debug_backtrace();
    $name = $bt[1]['class'];
    return $name;
  }

  class foo {
    function printClassName() {
      print(get_class_static() . "<br>");
     }
  }

  class bar extends foo {
  }

$f = new foo();
$b = new bar();
$f->printClassName();
$b->printClassName();

?>

In PHP4, it outputs
  foo
  bar
as you described.

However, in PHP5, due to the way the debug_backtrace() function has been modified (see http://bugs.php.net/bug.php?id=30828) the output is now
  foo
  foo

I have yet to figure out a way to get the original output in PHP5.  Any suggestions would be very useful, and if I find an answer I'll post it here.

Tomek Perlak [tomekperlak at tlen pl] (2006-11-10 02:16:18)

The __CLASS__ magic constant nicely complements the get_class() function.

Sometimes you need to know both:
- name of the inherited class
- name of the class actually executed

Here's an example that shows the possible solution:

<?php

class base_class
{
    function say_a()
    {
        echo "'a' - said the " . __CLASS__ . "<br/>";
    }

    function say_b()
    {
        echo "'b' - said the " . get_class($this) . "<br/>";
    }

}

class derived_class extends base_class
{
    function say_a()
    {
        parent::say_a();
        echo "'a' - said the " . __CLASS__ . "<br/>";
    }

    function say_b()
    {
        parent::say_b();
        echo "'b' - said the " . get_class($this) . "<br/>";
    }
}

$obj_b = new derived_class();

$obj_b->say_a();
echo "<br/>";
$obj_b->say_b();

?>

The output should look roughly like this:

'a' - said the base_class
'a' - said the derived_class

'b' - said the derived_class
'b' - said the derived_class

stangelanda at gmail dot com (2006-09-05 21:17:51)

claude noted that __CLASS__ always contains the class that it is called in, if you would rather have the class that called the method use get_class($this) instead.  However this only works with instances, not when called statically. 

<?php
  class A {
     function showclass() {
         echo get_class($this);
     }
  }

  class B extends A {}

  $a = new A();
  $b = new B();

  $a->showclass();
  $b->showclass();
  A::showclass();
  B::showclass();

  //results in "a", "b", false, false
?>

I tried keeping track of the class manually within the properties, but the following doesn't work either:

<?php
  class A {
     var $class = __CLASS__;
     function showclass() {
         echo $this->class;
     }
  }

  class B extends A {
     var $class = __CLASS__;
  }

  //results in "a", "b", NULL, NULL
?>

The best solution I could come up with was using debug_backtrace.  I assume there is a better way somehow, but I can't find it.  However the following works:

<?php
  class A {
     function showclass() {
        $backtrace = debug_backtrace();
        echo $backtrace[0]['class'];
     }
  }

  class B extends A {}

  //results in "a", "b", "a", "b"
?>

warhog at warhog dot net (2005-12-18 13:33:13)

There is another magic constant not mentioned above: __COMPILER_HALT_OFFSET__ - contains where the compiler halted - see http://www.php.net/manual/function.halt-compiler.php for further information.

vijaykoul_007 at rediffmail dot com (2005-09-21 21:59:21)

the difference between
__FUNCTION__ and __METHOD__ as in PHP 5.0.4 is that
__FUNCTION__ returns only the name of the function
while as __METHOD__ returns the name of the class alongwith the name of the function
class trick
{
function doit()
{
echo __FUNCTION__;
}
function doitagain()
{
echo __METHOD__;
}
}
$obj=new trick();
$obj->doit();
output will be ---- doit
$obj->doitagain();
output will be ----- trick::doitagain

karl __at__ streetlampsoftware__dot__com (2005-03-03 13:39:48)

Note that the magic constants cannot be included in quoted strings.
For instance,
echo "This is the filename: __FILE__";
will return exactly what's typed above.
echo "This is the filename: {__FILE__}";
will also return what's typed above.
The only way to get magic constants to parse in strings is to concatenate them into strings:
echo "This is the filename: ".__FILE__;

csaba at alum dot mit dot edu (2005-03-03 04:04:16)

Sometimes you might want to know whether a script is the top level script or whether it has been included.  That could be useful if you want to reuse the routines in another script, but you don't want to separate them out.  Here's a way that seems to be working for me (for both Apache2 module and CLI versions of PHP) on my Win XP Pro system.

By the way, if __FILE__ is within a function call, its value corresponds to the file it was defined in and not the file that it was called from.  Also, I used $script and strtolower instead of realpath because if the script is deleted after inclusion but before realpath is called (which could happen if the test is deferred), then realpath would return empty since it requires an extant file or directory.

Csaba Gabor from Vienna

<?php
if (amIincluded()) return;    // if we're included we only want function defs
function amIincluded() {
//    returns true/false depending on whether the currently
//    executing script is included or not
//    Don't put this function in an include file (duh)!
    $webP = !!$_SERVER['REQUEST_METHOD'];    // a web request?
    $script = preg_replace('/\//',DIRECTORY_SEPARATOR,
                           $_SERVER['SCRIPT_FILENAME']);
    return ($webP) ? (strtolower(__FILE__)!=strtolower($script)) :
           !array_key_exists("_REQUEST", $GLOBALS);
}
?>

lm arobase bible point ch (2004-12-08 14:17:34)

in reply to x123 at bestof dash inter:
I believe, this is not a bug, but a feature.
__FILE__ returns the name of the include file, while $PHP_SELF returns the relative name of the main file.
It is then easy to get the file name only with substr(strrchr($PHP_SELF,'/'),1)

claude at NOSPAM dot claude dot nl (2004-07-18 08:29:10)

Note that __CLASS__ contains the class it is called in; in lowercase. So the code:
class A
{
function showclass()
{
echo __CLASS__;
}
}
class B extends A
{
}
$a = new A();
$b = new B();
$a->showclass();
$b->showclass();
A::showclass();
B::showclass();
results in "aaaa";

ulrik (2004-03-04 07:44:54)

note that __FUNCTION__ define gives the the function name in lowercase

darwin[at]buchner[dot]net (2002-03-14 16:54:57)

As of version 4.0.6, there is also a handy predefined DIRECTORY_SEPARATOR constant which you can use to make you scripts more portatable between OS's with different directory structures.