Recurse Function Causing Apache Child Process To Restart

[CrYpTiC_MauleR]

Code

Language: php (GeSHi-highlighted)
<?php
 
    function recurse($func, $args, $keys = true)
    {
        if (is_string($args[0]))
        {
            return call_user_func_array($func, $args);
        }
        else if (is_array($args[0]))
        {
            $data = $args[0];
            unset($args[0]);
            $new_data = array();
            foreach ($data as $key => $value)
            {
                if ($keys)
                {
                    $key = call_user_func_array($func, array($key, $args));
                }
            $new_data[$key] = (is_string($value))
                ? call_user_func_array($func, array($value, $args))
                : recurse($func, array(array($key => $value), $args)); 
            }
            return $new_data;
        }
    }
 
    function test($data, $pad = false)
    {
        $data = strtoupper($data);
        if ($pad)
        {
            $data = '___' . $data . '___';
        }
        return $data;
    }
 
$array = 'mmm';
//$array = array('bbb', 'ccc', array('ddd', 'eee' => 'ddd', array('fff')));
echo test('aaa', true);
$array = recurse('test', array($array, true));
print_r($array);
 
?>

I made this recurse function to apply any function to both the key and value of an array or just a string recursively. But for some reason when I use a multidimensional array it causes Firefox to say the following:

"The connection to the server was reset while the page was loading."

Checking the Apache error logs says this:

[notice] Parent: child process exited with status 128 -- Restarting.

I can't spot the logic problem with the function, is there an endless loop I don't see? If that is the case would Apache just not exhaust its resources opposed to having the child process terminate? Any insight on what could be causing this?

[VGR]

well, I tried it on my own server and I received quasi instanatly this answer :
___AAA______MMM___

I don't know if it's correct of not, but I didn't get any error nor infinite loop

perhaps you could check out your server signature and compre it to mine : Apache/2.2.6 (Win32) PHP/5.2.5

[CrYpTiC_MauleR]

You need to uncomment:

//$array = array('bbb'.....

I put a test $array before to show that functions work without an array, the commented line is the one that when ran will cause the issue.

[VGR]

you sure have a problem. I got no dramatic error nor loop, but saw this :
PHP Fatal error:  Allowed memory size of 16777216 bytes exhausted (tried to al
locate 6944 bytes) in *.php on line 13


line 13 is your recurse() line :
            foreach ($data as $key => $value)


add some tracing...

[GrandSchtroumpf]

This works...
I added a separate $data argument to the transform function.  It simplifies the code.

Code

Language: php (GeSHi-highlighted)
<?php
 
	function transform($data, $func, $args, $process_keys_flag = true) {
 
		if (is_string($data)) {
			// String => apply function on string
			return call_user_func_array($func, array_merge(array($data), $args));
		}
 
		else if (is_array($data)) {
			// Array => apply transform on keys and values
			$new_data = array();
			foreach ($data as $key => $value) {
				$new_value = transform($value, $func, $args, $process_keys_flag);
				if (is_string($key) && $process_keys_flag) {
					$new_key = transform($key, $func, $args);
					$new_data[$new_key] = $new_value;
				}
				else {
					$new_data[] = $new_value;
				}
			}
			return $new_data;
		}
 
	}
 
	function test($data, $pad = false, $pad2 = false) {
 
		$data = strtoupper($data);
		if ($pad) {
			$data = '___' . $data . '___';
		}
		if ($pad2) {
			$data = 'xxx' . $data . 'xxx';
		}
		return $data;
 
	}
 
	 
$array = array('bbb', 'ccc', array('ddd', 'eee' => 'ddd', array('fff')));
 
echo "<pre>before transform: ";
print_r($array);
echo "</pre>";
 
$array2 = transform($array, 'test', array(true, true));
echo "<pre>after transform (true, true): ";
print_r($array2);
echo "</pre>";
 
$array3 = transform($array, 'test', array(true, false));
echo "<pre>after transform (true, false): ";
print_r($array3);
echo "</pre>";
 
$array4 = transform($array, 'test', array(false, true));
echo "<pre>after transform (false, true): ";
print_r($array4);
echo "</pre>";
 
?>

[CrYpTiC_MauleR]

I'll test the code when I get on my server, thanks.

Do you happen to know what the problem was? I still don't see what went wrong.

[rdivilbiss]

Off topic. Purse hook installed per request.

[GrandSchtroumpf]

The problem in the original code is that your arrays are not built correctly.

You unset $args[0], then you create a new array that you pass to the recurse function:

>>    array(array($key => $value), $args)

This is wrong... the resulting array is not what you need.

It's an array with 2 entries:
    [ 0 ] : an array that contains your data.
    [ 1 ] : an array that contains your arguments.

What you really need is this:
    [ 0 ] : data
    [ 1 ] : arg 1
    [ 2 ] : arg 2
    [ 3 ] : arg 3
      ...
    [ n ] : arg n

You could fix it using "array_merge", but there is a much simpler solution:
Don't unset $args[0] and use "$args[0] = data".

Another small problem is that you forgot to pass "$keys" to your recursion call.
Bloody default argument values!!!  Use them wisely... or don't use them at all.

To simplify the code I also changed this:
            $new_data[$key] = (is_string($value)) ? call_user_func_array(...) : recurse(...);
To this:
            $new_data[$key] = recurse(...);

See fixed code here:

Code

Language: php (GeSHi-highlighted)
<pre>
<?php
	
	function recurse($func, $args, $keys)
	{
		if (is_string($args[0]))
		{
			return call_user_func_array($func, $args);
		}
		else if (is_array($args[0]))
		{
			$data = $args[0];
			$new_data = array();
			foreach ($data as $key => $value)
			{
				if ($keys)
				{
					$args[0] = $key;
					$key = call_user_func_array($func, $args);
				}
				$args[0] = $value;
				$new_data[$key] = recurse($func, $args, $keys); 
			}
			return $new_data;
		}
	}
	
	function test($data, $pad, $pad2) 
	{
		
		$data = strtoupper($data);
		if ($pad) {
			$data = '___' . $data . '___';
		}
		if ($pad2) {
			$data = 'xxx' . $data . 'xxx';
		}
		return $data;
		
	}
	
	$array = 'mmm';
	$array = array('bbb', 'ccc', array('ddd', 'eee' => 'ddd', array('fff')));
	$array = recurse('test', array($array, true, true), true);
	print_r($array);
	
?>
</pre>