Viewing File: /usr/local/cpanel/3rdparty/wpinstaller/src/Common/Process.php

<?php
namespace Common;

class Process {

    public static function run_process($cmd, $downstream_data = NULL) {

        # create tempfile for STDERR
        $temp = tempnam('/tmp', 'wp-installer-');

        // setup stream handling
        $stream_handling = array(
            0 => array("pipe", "r"),        // stdin (unused)
            1 => array("pipe", "w"),        // direct stdout to pipe
            2 => array("file", $temp, 'a'), // direct stderr to file
        );

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

        $tmp_fh = fopen($temp, 'r');

        unlink($temp);

        // check that we could start the process
        if (!is_resource($process)) {
            throw new Exception('Could not start process: ' . $cmd);
        }

        // pass data to stdin if it's given
        if ($downstream_data) {
            fwrite($pipes[0], $downstream_data);
        }
        fclose($pipes[0]);

        // get process data
        $output   = stream_get_contents($pipes[1]);
        fclose($pipes[1]);

        # gather warnings, close fh
        $warnings = stream_get_contents($tmp_fh);
        fclose($tmp_fh);

        // close process
        $return_value = proc_close($process);

        // pass STDERR warnings through to the parent process
        fwrite(STDERR, $warnings);

        // strip empty lines
        // array_filter w/ no function removes non-truthy values (empty strings)
        $filtered_output = implode("\n", array_filter(explode("\n", $output)));

        // attempt to parse as JSON
        $json_output = (array) json_decode($filtered_output, true);

        $trace = [];

        // look for error cases
        $error = $return_value > 0 || !$json_output || $json_output['success'] !== true;

        // capture the trace if it exists
        if($json_output && $json_output['trace']) {
            $trace = $json_output['trace'];
            unset($json_output['trace']);
        }

        return array(
            'output'       => $filtered_output,
            'json_output'  => $json_output,
            'warnings'     => $warnings,
            'error'        => $error,
            'trace'        => $trace
        );
    }

    public static function su($username) {

        $user_info = posix_getpwnam($username);

        if( empty($user_info['uid']) ) {
            throw new \Exception("User '{$username}' could not be found");
        }

        $effective_user = posix_getpwuid( posix_geteuid() )['name'];

        if ($effective_user == $user_info['name']) {
            // Process is running as expected user already
            return true;
        }

        if (posix_setgid($user_info['gid']) !== true) {
            throw new \Exception("Failed to set the owning group of this process");
        }

        if (posix_initgroups($user_info['name'], $user_info['gid']) !== true) {
            throw new \Exception("Failed to set the group access list for this process");
        }

        if (posix_setuid($user_info['uid']) !== true) {
            throw new \Exception("Failed to set the owning user of this process");
        }
    }

}

?>