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)