lesterchan
Bug: Fatal error when system() function is disabled
Hello,
First of all, thank you for the great plugin, I really like it. However, I found a small “bug” or rather an improvement to a function that I think would be useful.
Description:
The plugin throws a fatal error when the system() function is disabled on the server (which is common on shared hosting for security reasons).
The Error Message:
PHP Fatal error: Uncaught Error: Call to undefined function system() in /wp-content/plugins/wp-serverinfo/wp-serverinfo.php:535
Root Cause:
The get_serverload() function here at wp-serverinfo.php tries to use system('uptime') without checking if the function is available or disabled via disable_functions in php.ini.
My Proposed Solution:
Check if system functions are available before calling them. Here's a fixed version that tries multiple alternatives:
### Function: Get The Server Load (PATCHED VERSION)
function get_serverload() {
$server_load = '';
if(PHP_OS != 'WINNT' && PHP_OS != 'WIN32') {
if(@file_exists('/proc/loadavg') ) {
if ($fh = @fopen( '/proc/loadavg', 'r' )) {
$data = @fread( $fh, 6 );
@fclose( $fh );
$load_avg = explode( " ", $data );
$server_load = trim($load_avg[0]);
}
} else if(function_exists('system') && !in_array('system', explode(',', ini_get('disable_functions')))) {
// Only use if system() is available and not disabled
$data = @system('uptime');
if($data !== false) {
preg_match('/(.*):{1}(.*)/', $data, $matches);
if(isset($matches[2])) {
$load_arr = explode(',', $matches[2]);
$server_load = trim($load_arr[0]);
}
}
} else if(function_exists('exec') && !in_array('exec', explode(',', ini_get('disable_functions')))) {
// Try exec() as alternative
$data = @exec('uptime 2>&1', $output, $return_var);
if($return_var === 0 && !empty($data)) {
preg_match('/load average: ([0-9\.]+)/', $data, $matches);
if(isset($matches[1])) {
$server_load = $matches[1];
}
}
} else if(function_exists('shell_exec') && !in_array('shell_exec', explode(',', ini_get('disable_functions')))) {
// Try shell_exec() as alternative
$data = @shell_exec('uptime 2>&1');
if(!empty($data)) {
preg_match('/load average: ([0-9\.]+)/', $data, $matches);
if(isset($matches[1])) {
$server_load = $matches[1];
}
}
}
}
if(empty($server_load)) {
$server_load = __('N/A', 'wp-serverinfo');
}
return $server_load;
}
The Benefits
- Prevents fatal errors on servers with disabled system functions
- Tries multiple alternatives (system, exec, shell_exec)
- Gracefully falls back to "N/A" when no method is available
- Maintains backward compatibility
Testet Environment:
- WordPress 6.x
- PHP 8.x with
disable_functions = system,exec,shell_exec,passthru - Shared hosting environment
Hey Lester, i just wanted to report this issue so you’re aware of it. But if you prefer, I can also create a pull request with the fix,totally fine either way, just let me know what works best for you.