[PHP-NOTES] note 130621 added to function.shell-exec

<?php

/**
 * Execute a shell command using the best available method.
 * @param string $cmd The command to execute.
 * @return string The output of the command, or a not supported message.
 */
function php_exec($cmd) {
    // 1. exec
    if (function_exists('exec')) {
        $output = array();
        $return_var = 0;
        exec($cmd, $output, $return_var);
        // Use "\n" to preserve line breaks, not space
        return implode("\n", $output); 
    }
    // 2. shell_exec
    else if (function_exists('shell_exec')) {
        return shell_exec($cmd);
    }
    // 3. system (Fixed: Added output buffering)
    else if (function_exists('system')) {
        ob_start();
        system($cmd);
        $output = ob_get_contents();
        ob_end_clean();
        return $output;
    }
    // 4. passthru
    else if (function_exists('passthru')) {
        ob_start();
        passthru($cmd);
        $output = ob_get_contents();
        ob_end_clean();
        return $output;
    }
    // 5. proc_open (Fixed: Added proper closing of resources)
    else if (function_exists('proc_open')) {
        $descriptorspec = array(
            0 => array("pipe", "r"), // stdin
            1 => array("pipe", "w"), // stdout
            2 => array("pipe", "w")  // stderr
        );

        $process = proc_open($cmd, $descriptorspec, $pipes);

        if (is_resource($process)) {
            // Write to stdin if needed (skipped here)
            fclose($pipes[0]);

            // Read stdout
            $output = stream_get_contents($pipes[1]);
            fclose($pipes[1]);

            // Read stderr (optional, usually good to have)
            // $errors = stream_get_contents($pipes[2]); 
            fclose($pipes[2]);

            // Close the process to avoid zombies
            proc_close($process);
            
            return $output;
        }
    }
    
    return "@PHP_COMMAND_NOT_SUPPORT";
}

// Example of safer usage
$user_input = "some_filename.txt";
$clean_input = escapeshellarg($user_input); 
$output = php_exec("ls -l " . $clean_input);
----
Server IP: 206.189.2.9
Probable Submitter: 27.147.206.73
----
Manual Page -- https://php.net/manual/en/function.shell-exec.php
Edit        -- https://main.php.net/note/edit/130621
Del: integrated  -- https://main.php.net/note/delete/130621/integrated
Del: useless     -- https://main.php.net/note/delete/130621/useless
Del: bad code    -- https://main.php.net/note/delete/130621/bad+code
Del: spam        -- https://main.php.net/note/delete/130621/spam
Del: non-english -- https://main.php.net/note/delete/130621/non-english
Del: in docs     -- https://main.php.net/note/delete/130621/in+docs
Del: other reasons-- https://main.php.net/note/delete/130621
Reject      -- https://main.php.net/note/reject/130621
Search      -- https://main.php.net/manage/user-notes.php