get_defined_functions()

(PHP 4 >= 4.0.4, PHP 5, PHP 7)

返回所有已定义函数的数组

说明

get_defined_functions([bool $exclude_disabled=FALSE]): array

获取所有已定义函数的数组。

参数

$exclude_disabled: 禁用的函数是否应该在返回的数据里排除。

返回值

返回数组，包含了所有已定义的函数，包括内置(internal)和用户定义的函数。可通过$arr["internal"]来访问系统内置函数，通过$arr["user"]来访问用户自定义函数(参见示例)。

更新日志

版本	说明
PHP 7.0.15, PHP 7.1.1	增加`$exclude_disabled`参数。

范例

Example #1get_defined_functions()例子

<?php
function myrow($id, $data)
{
    return "<tr><th>$id</th><td>$data</td></tr>\n";
}
$arr = get_defined_functions();
print_r($arr);
?>

以上例程的输出类似于：

Array
(
    [internal] => Array
        (
            [0] => zend_version
            [1] => func_num_args
            [2] => func_get_arg
            [3] => func_get_args
            [4] => strlen
            [5] => strcmp
            [6] => strncmp
            ...
            [750] => bcscale
            [751] => bccomp
        )
    [user] => Array
        (
            [0] => myrow
        )
)

参见

function_exists() 如果给定的函数已经被定义就返回 TRUE
get_defined_vars() 返回由所有已定义变量所组成的数组
get_defined_constants() 返回所有常量的关联数组，键是常量名，值是常量值
get_declared_classes() 返回由已定义类的名字所组成的数组

You can list all arguments using ReflectionFunction class. It's not necessary to parse selected files/files as suggested by Nguyet.Duc.
http://php.net/manual/pl/class.reflectionfunction.php
Example:
<?php
function foo(&$bar, $big, $small = 1) {}
function bar($foo) {}
function noparams() {}
function byrefandopt(&$the = 'one') {}
$functions = get_defined_functions();
$functions_list = array();
foreach ($functions['user'] as $func) {
    $f = new ReflectionFunction($func);
    $args = array();
    foreach ($f->getParameters() as $param) {
        $tmparg = '';
        if ($param->isPassedByReference()) $tmparg = '&';
        if ($param->isOptional()) {
            $tmparg = '[' . $tmparg . '$' . $param->getName() . ' = ' . $param->getDefaultValue() . ']';
        } else {
            $tmparg.= '&' . $param->getName();
        }
        $args[] = $tmparg;
        unset ($tmparg);
    }
    $functions_list[] = 'function ' . $func . ' ( ' . implode(', ', $args) . ' )' . PHP_EOL;
}
print_r($functions_list);
?>
Output:
Array
(
  [0] => function foo ( &&bar, &big, [$small = 1] )
  [1] => function bar ( &foo )
  [2] => function noparams ( )
  [3] => function byrefandopt ( [&$the = one] )
)

Here's a useful trick with the get_defined_functions function - show all available functions with a link to the documentation (you can even change the mirror it goes to):
<?php
 // the php mirror 
 $php_host = "http://us2.php.net/";
 // the number of cols in our table
 $num_cols = 3;
 $ar = get_defined_functions();
 $int_funct = $ar[internal];
 sort($int_funct);
 $count = count($int_funct);
?>
<html>
 <head>
 <title>
  Available PHP Functions
 </title>
 </head>
 <body>
 <p>
  <?php print $count; ?> functions   
  available on 
  <?php 
   print $_SERVER[SERVER_NAME]; 
   ?>
  (<a href="<?php print $php_host;?>" 
  target="phpwin">php</a>
  version 
  <?php print phpversion(); ?>)
 </p>
 <table align="center" border="2">
  <tr> 
<?php
 for($i=0;$i<$count;$i++) {
  $doc = $php_host 
   . "manual/en/function."
   . strtr($int_funct[$i], "_", "-") 
   . ".php";
  print "  <td><a href=\"" . $doc 
   . "\" target=\"phpwin\">" 
   . $int_funct[$i] 
   . "</a></td>\n";
  if(($i > 1) 
   && (($i+$num_cols)%$num_cols==($num_cols-1)))  
   print "  </tr>\n  <tr>\n";
  }
 for($i=($num_cols-($count%$num_cols));$i>0;$i--) 
  print "  <td>&nbsp;</td>\n";
?>
 </table>
 </body>
</html>

Please note that functions created with create_function() are not returned.
(However that might change in a later version)

At least with PHP 4.2.3 on a GNU/Linux/Apache platform, get_defined_functions() returns user-defined functions as all-lower case strings regardless of how the functions are capitalized when they are defined.
Threw me for a loop.

look at here, list all the defined function on your php-Version and give as well formatted output width links onto the php-manual:
<html><head>
<style type="text/css"><!--
li{font-family:Verdana,Arail,sans-serif;width:500px;margin-top:7px;}
a{padding:4px;}
a.a1{font-size:12px;background-color:#CCCCCC;color:#663300;}
a.a1:hover{background-color:#663300;color:#CCCCCC;}
a.a1:visited{background-color:#fff;color:#999;}
a.a1:visited:hover{background-color:#fff;color:#999;}
a.a0{font-size:12px;background-color:#CCCCFF;color:#663399;}
a.a0:hover{background-color:#663399;color:#CCCCFF;}
a.a0:visited{background-color:#ffC;color:#999;}
a.a0:visited:hover{background-color:#ffC;color:#999;}
--></style>
</head><body style="background-color:#999;">
<?php
$arr = get_defined_functions();
foreach($arr as $zeile){
sort($zeile);$s=0;
foreach($zeile as $bzeile){
$s=($s)?0:1;
echo "<li><a class='a".$s."' href='http://de.php.net/".$bzeile."'>".$bzeile."</a></li>";}
}
?>
</body>
</html>

To search for a function.
<html>
<head>
<title>List of all Internal functions</title>
<style type="text/css">
body {
  background-color:#FFFFFF;
  color:#222222;
  font-size: 11px;
  font-family: arial, tahoma;
}
table {
  color:#222222;
  font-size: 11px;
  font-family: arial, tahoma;
}
tr.found {
  background-color:#66EE00;
  font-weight: bold;
}
a:link {
  color:#222222;
}
a:visited {
  color:#CCCCCC;
}
a:active {
  color:#444444;
}
a:hover {
  text-decoration: underline;
}
</style>
</head>
<body>
<p>
  <form method="GET">
  Search: <input type="text" name="search"><br>
  <input type="submit">
  </form>
</p>
<?php
  if (!empty($_GET['search'])) {
    echo '<p>' . '<a href="#' . $_GET['search'] . '">' .
    'Goto ' . $_GET['search'] . '</a>' . 
    '<script type="text/javascript">
      window.onload = function() {
        document.location += "#' . $_GET['search'] . '";
        return true;
      }
    </script>
    </p>';
  }
?>
<p>
  <table>
<?php
  $country = 'us';
  $functions = get_defined_functions();
  $functions = $functions['internal'];
  $num = 0;
  foreach($functions as $function) {
    $num++;
    echo '<tr ' . (($_GET['search'] == $function) ? 'class="found"' : '') . '><td>' . 
    number_format($num) . '</td><td>' . '<a name="' . $function . '" href="http://' . $country . '.php.net/' . 
    $function . '">' . $function . '</a>' . '</td></tr>';
  }
?>
  </table>
</p>
</body>
</html>

We can also get the function names with this simple foreach
<?php
  
  //Since its a two dimensional array
  $functions = get_defined_functions();
   
  //We can use nested foreach to get the function names
  foreach($functions as $function){
     foreach($function as $thisFunc){
       echo $thisFunc . "<br />";
     }
   }
  
?>

This is rather a simple non-confusing script to get the function names linked to its manual page on php.net. Hope it helps someone. Commented script is self explainatory
<?php
  
  /*declare a variable to php manual of functions.
  change the $lng to the region you want it for,
  i-e en/es/de etc etc */
  $lng = "es";
  $url = "http://www.php.net/manual/".$lng."/function.";
  
  // get defined functions in a variable (it will be a 2D array)
  $functions = get_defined_functions();
  
  // Run nested foreach to get the function names
  foreach($functions as $function){
    foreach ($function as $functionName){
      
      /* Since php manual is using hyphens instead of underscores
      for functions, we will convert underscores to hyphen whereever
      there is one. */
      if(strpos($functionName,"_") !== false){
        $functionForURL = str_replace("_","-",$functionName);
      } else {
        $functionForURL = $functionName;
      }
      
      /* echo the link */
      echo "<a href='".$url.$functionForURL.".php'>".$functionName."</a><br />";
    }
  }
  
?>

get_defined_functions() just returns a list of function names without function arguments. Here is the code to list user-defined function names plus arguments:
<?php
  $content = file_get_contents('example.php');
  preg_match_all("/(function )(\S*\(\S*\))/", $content, $matches);
  foreach($matches[2] as $match) {
    $function[] = "// " . trim($match) . "<br />\n";
  }
  natcasesort($function);
  $functionlist .= "/* Functions in this file */<br />\n";
  $functionlist .= "/**************************/<br />\n\n";
  $functionlist .= implode('', $function);
  echo $functionlist;
?>
Output:
/* Functions in this file */
/**************************/
// add_data($data)
// add_files($list)
// archive($name)
// bzip_file($name)

A quick way of using this function:
<?php
// ALL USER DEFINED FUNCTIONS
$arr = get_defined_functions();
foreach ($arr['user'] as $key => $value){
echo $value.'<br />';
}
// ALL USER DEFINED FUNCTIONS
// ALL INTERNAL FUNCTIONS
$arr = get_defined_functions();
foreach ($arr['internal'] as $key => $value){
echo $value.'<br />';
}
// ALL INTERNAL FUNCTIONS
?>

for user defined function
<?php
/**
 * @param string $function_name The user function name, as a string.
 * @return Returns TRUE if function_name exists and is a function, FALSE otherwise.
 */
function user_func_exists($function_name = 'do_action') {
  
  $func = get_defined_functions();
  
  $user_func = array_flip($func['user']);
  
  unset($func);
  
  return ( isset($user_func[$function_name]) );  
}
?>