Skip to content
system.inc.php 56.3 KiB
Newer Older
tbrehm's avatar
tbrehm committed
<?php
redray's avatar
redray committed

tbrehm's avatar
tbrehm committed
/*
redray's avatar
redray committed
Copyright (c) 2007, Till Brehm, projektfarm Gmbh
tbrehm's avatar
tbrehm committed
All rights reserved.

Redistribution and use in source and binary forms, with or without modification,
are permitted provided that the following conditions are met:

    * Redistributions of source code must retain the above copyright notice,
      this list of conditions and the following disclaimer.
    * Redistributions in binary form must reproduce the above copyright notice,
      this list of conditions and the following disclaimer in the documentation
      and/or other materials provided with the distribution.
    * Neither the name of ISPConfig nor the names of its contributors
      may be used to endorse or promote products derived from this software without
      specific prior written permission.

THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE,
EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/

class system{

	var $FILE = '/root/ispconfig/scripts/lib/classes/ispconfig_system.lib.php';
	var $server_id;
	var $server_conf;
	var $data;
Marius Cramer's avatar
Marius Cramer committed
	var $min_uid = 500;
	var $min_gid = 500;
	
	/**
	 * Construct for this class
	 *
	 * @return system
	 */
	public function __construct(){
		//$this->server_id = $go_info['isp']['server_id'];
		//$this->server_conf = $go_info['isp']['server_conf'];
		$this->server_conf['passwd_datei'] = '/etc/passwd';
		$this->server_conf['shadow_datei'] = '/etc/shadow';
		$this->server_conf['group_datei'] = '/etc/group';
	/**
	 * Get the hostname from the server
	 *
	 * @return string
	 */
	public function hostname(){
		$dist = $this->server_conf['dist'];

		ob_start();
		passthru('hostname');
		$hostname = ob_get_contents();
		ob_end_clean();
		$hostname = trim($hostname);
		ob_start();
		if(!strstr($dist, 'freebsd')){
			passthru('dnsdomainname');
		} else {
			passthru('domainname');
		}
		$domainname = ob_get_contents();
		ob_end_clean();
		$domainname = trim($domainname);
		if($domainname != ""){
			if(!strstr($hostname, $domainname)) $hostname .= ".".$domainname;
		}
		return $hostname;
	/**
	 * Add an user to the system
	 */
	public function adduser($user_username, $uid, $gid, $username, $homedir, $shell, $passwort = '*'){
		global $app;
		if($this->is_user($user_username)){
			return false;
		} else {
			if(trim($user_username) != '') {
				$user_datei = $this->server_conf['passwd_datei'];
				$shadow_datei = $this->server_conf['shadow_datei'];
				$shell = realpath($shell);
				if(trim($passwort) == '') $passwort = '*';
				$new_user = "\n$user_username:x:$uid:$gid:$username:$homedir:$shell\n";
				$app->log->msg('USER: '.$new_user);
				$app->file->af($user_datei, $new_user);
				if($shadow_datei == '/etc/shadow'){
					$datum = time();
					$tage = floor($datum/86400);
					$new_passwd = "\n$user_username:$passwort:$tage:0:99999:7:::\n";
				} else {
					$new_passwd = "\n$user_username:$passwort:$uid:$gid::0:0:$username:$homedir:$shell\n";
				}
				$app->file->af($shadow_datei, $new_passwd);
				// TB: leere Zeilen entfernen
				$app->file->remove_blank_lines($shadow_datei);
				$app->file->remove_blank_lines($user_datei);
				// TB: user Sortierung deaktiviert
				//$this->order_users_groups();
				if($shadow_datei != '/etc/shadow'){
					$app->file->af($shadow_datei, "\n");
					// TB: leere Zeilen entfernen
					$app->file->remove_blank_lines($shadow_datei);
					$app->log->caselog("pwd_mkdb $shadow_datei &> /dev/null", $this->FILE, __LINE__);
	/**
	 * Update users when someone edit it
	 *
	 */
	function updateuser($user_username, $uid, $gid, $username, $homedir, $shell, $passwort = '*'){
		//* First delete the users
		$this->deluser($user_username);
		//* Add the user again
		$this->adduser($user_username, $uid, $gid, $username, $homedir, $shell, $passwort);
	/**
	 * Lock the user
	 *
	 */
	function deactivateuser($user_username){
		$passwort = str_rot13($this->getpasswd($user_username));
		$user_attr = $this->get_user_attributes($user_username);
		$uid = $user_attr['uid'];
		$gid = $user_attr['gid'];
		$username = $user_attr['name'];
		$homedir = $user_attr['homedir'];
		$shell = '/dev/null';
		$this->deluser($user_username);
		$this->adduser($user_username, $uid, $gid, $username, $homedir, $shell, $passwort);
	/**
	 * Delete a user from the system
	 *
	 */
	function deluser($user_username){
		global $app;
		if($this->is_user($user_username)){
			$user_datei = $this->server_conf['passwd_datei'];
			$shadow_datei = $this->server_conf['shadow_datei'];
			$users = $app->file->rf($user_datei);
			$lines = explode("\n", $users);
			if(is_array($lines)){
				$num_lines = sizeof($lines);
				for($i=0;$i<$num_lines;$i++){
					if(trim($lines[$i]) != ''){
						list($f1, ) = explode(':', $lines[$i]);
						if($f1 != $user_username) $new_lines[] = $lines[$i];
					}
				}
				$new_users = implode("\n", $new_lines);
				$app->file->wf($user_datei, $new_users);
				unset($new_lines);
				unset($lines);
				unset($new_users);
			}
			$app->file->remove_blank_lines($user_datei);

			$passwds = $app->file->rf($shadow_datei);
			$lines = explode("\n", $passwds);
			if(is_array($lines)){
				$num_lines = sizeof($lines);
				for($i=0;$i<$num_lines;$i++){
					if(trim($lines[$i]) != ''){
						list($f1, ) = explode(':', $lines[$i]);
						if($f1 != $user_username) $new_lines[] = $lines[$i];
					}
				}
				$new_passwds = implode("\n", $new_lines);
				$app->file->wf($shadow_datei, $new_passwds);
				unset($new_lines);
				unset($lines);
				unset($new_passwds);
			}
			$app->file->remove_blank_lines($shadow_datei);

			$group_file = $app->file->rf($this->server_conf['group_datei']);
			$group_file_lines = explode("\n", $group_file);
			foreach($group_file_lines as $group_file_line){
				if(trim($group_file_line) != ''){
					list($f1, $f2, $f3, $f4) = explode(':', $group_file_line);
					$group_users = explode(',', str_replace(' ', '', $f4));
					if(in_array($user_username, $group_users)){
						$g_users = array();
						foreach($group_users as $group_user){
							if($group_user != $user_username) $g_users[] = $group_user;
						}
						$f4 = implode(',', $g_users);
					}
					$new_group_file[] = $f1.':'.$f2.':'.$f3.':'.$f4;
				}
			}
			$new_group_file = implode("\n", $new_group_file);
			$app->file->wf($this->server_conf['group_datei'], $new_group_file);
			// TB: auskommentiert
			//$this->order_users_groups();

			if($shadow_datei != '/etc/shadow'){
				$app->file->af($shadow_datei, "\n");
				$app->log->caselog("pwd_mkdb $shadow_datei &> /dev/null", $this->FILE, __LINE__);
			}
			return true;
		} else {
			return false;
		}
	/**
	 * Add a usergroup to the system
	 *
	 */
	function addgroup($group, $gid, $members = ''){
		global $app;
		if($this->is_group($group)){
			return false;
		} else {
			$group_datei = $this->server_conf['group_datei'];
			$shadow_datei = $this->server_conf['shadow_datei'];
			$new_group = "\n$group:x:$gid:$members\n";
			$app->file->af($group_datei, $new_group);

			// TB: auskommentiert
			//$this->order_users_groups();
			if($shadow_datei != '/etc/shadow'){
				$app->log->caselog("pwd_mkdb $shadow_datei &> /dev/null", $this->FILE, __LINE__);
			}
			return true;
		}
	/**
	 * Update usersgroup in way to delete and add it again
	 *
	 */
	function updategroup($group, $gid, $members = ''){
		$this->delgroup($group);
		$this->addgroup($group, $gid, $members);
	/**
	 * Delete a usergroup from the system
	 *
	 */
	function delgroup($group){
		global $app;
		if($this->is_group($group)){
			$group_datei = $this->server_conf['group_datei'];
			$shadow_datei = $this->server_conf['shadow_datei'];
			$groups = $app->file->rf($group_datei);
			$lines = explode("\n", $groups);
			if(is_array($lines)){
				$num_lines = sizeof($lines);
				for($i=0;$i<$num_lines;$i++){
					if(trim($lines[$i]) != ''){
						list($f1, ) = explode(':', $lines[$i]);
						if($f1 != $group) $new_lines[] = $lines[$i];
					}
				}
				$new_groups = implode("\n", $new_lines);
				$app->file->wf($group_datei, $new_groups);
				unset($new_lines);
				unset($lines);
				unset($new_groups);
			}
			// TB: auskommentiert
			//$this->order_users_groups();
			if($shadow_datei != '/etc/shadow'){
				$app->log->caselog("pwd_mkdb $shadow_datei &> /dev/null", $this->FILE, __LINE__);
			}
			return true;
		} else {
			return false;
		}
	/**
	 * Order usergroups
	 *
	 */
	function order_users_groups(){
		global $app;
		$user_datei = $this->server_conf['passwd_datei'];
		$shadow_datei = $this->server_conf['shadow_datei'];
		$group_datei = $this->server_conf['group_datei'];

		$groups = $app->file->no_comments($group_datei);
		$lines = explode("\n", $groups);
		if(is_array($lines)){
			foreach($lines as $line){
				if(trim($line) != ''){
					list($f1, $f2, $f3, $f4) = explode(':', $line);
					$arr[$f3] = $line;
				}
			}
		}
		ksort($arr);
		reset($arr);
		if($shadow_datei != '/etc/shadow'){
			$app->file->wf($group_datei, $app->file->remove_blank_lines(implode("\n", $arr), 0)."\n");
		}else {
			$app->file->wf($group_datei, $app->file->remove_blank_lines(implode("\n", $arr), 0));
		}
		unset($arr);

		$users = $app->file->no_comments($user_datei);
		$lines = explode("\n", $users);
		if(is_array($lines)){
			foreach($lines as $line){
				if(trim($line) != ""){
					list($f1, $f2, $f3, ) = explode(':', $line);
					if($f1 != 'toor'){
						$arr[$f3] = $line;
					} else {
						$arr[70000] = $line;
					}
				}
			}
		}
		ksort($arr);
		reset($arr);
		$app->file->wf($user_datei, $app->file->remove_blank_lines(implode("\n", $arr), 0));
		unset($arr);

		$passwds = $app->file->no_comments($shadow_datei);
		$lines = explode("\n", $passwds);
		if(is_array($lines)){
			foreach($lines as $line){
				if(trim($line) != ''){
					list($f1, $f2, $f3, ) = explode(':', $line);
					if($f1 != 'toor'){
						$uid = $this->getuid($f1);
						if(!is_bool($uid)) $arr[$uid] = $line;
					} else {
						$arr[70000] = $line;
					}
				}
			}
		}
		ksort($arr);
		reset($arr);
		$app->file->wf($shadow_datei, $app->file->remove_blank_lines(implode("\n", $arr), 0));
		unset($arr);
	/**
	 * Find a user / group id
	 *
	 */
	function find_uid_gid($min, $max){
		global $app;
		if($min < $max && $min >= 0 && $max >= 0 && $min <= 65536 && $max <= 65536 && is_int($min) && is_int($max)){
			for($i=$min;$i<=$max;$i++){
				$uid_arr[$i] = $gid_arr[$i] = 1;
			}
			$user_datei = $this->server_conf['passwd_datei'];
			$group_datei = $this->server_conf['group_datei'];

			$users = $app->file->no_comments($user_datei);
			$lines = explode("\n", $users);
			if(is_array($lines)){
				foreach($lines as $line){
					if(trim($line) != ''){
						list($f1, $f2, $f3, $f4, $f5, $f6, $f7) = explode(':', $line);
						if($f3 >= $min && $f3 <= $max) unset($uid_arr[$f3]);
					}
				}
				if(!empty($uid_arr)){
					foreach($uid_arr as $key => $val){
						$uids[] = $key;
					}
					$min_uid = min($uids);
					unset($uid_arr);
				} else {
					return false;
				}
			}

			$groups = $app->file->no_comments($group_datei);
			$lines = explode("\n", $groups);
			if(is_array($lines)){
				foreach($lines as $line){
					if(trim($line) != ''){
						list($f1, $f2, $f3, $f4) = explode(':', $line);
						if($f3 >= $min && $f3 <= $max) unset($gid_arr[$f3]);
					}
				}
				if(!empty($gid_arr)){
					foreach($gid_arr as $key => $val){
						$gids[] = $key;
					}
					$min_gid = min($gids);
					unset($gid_arr);
				} else {
					return false;
				}
			}

			$result = array_intersect($uids, $gids);
			$new_id = (max($result));
			unset($uids);
			unset($gids);
			unset($result);
			if($new_id <= $max){
				return $new_id;
			} else {
				return false;
			}
		} else {
			return false;
		}
	/**
	 * Check if the users is really a user into the system
	 *
	 */
	function is_user($user){
		global $app;
		$user_datei = $this->server_conf['passwd_datei'];
		$users = $app->file->no_comments($user_datei);
		$lines = explode("\n", $users);
		if(is_array($lines)){
			foreach($lines as $line){
				if(trim($line) != ''){
					list($f1, $f2, $f3, $f4, $f5, $f6, $f7) = explode(':', $line);
					if($f1 == $user) return true;
				}
			}
		}
		return false;
	/**
	 * Check if the group is on this system
	 *
	 */
	function is_group($group){
		global $app;
		$group_datei = $this->server_conf['group_datei'];
		$groups = $app->file->no_comments($group_datei);
		$lines = explode("\n", $groups);
		if(is_array($lines)){
			foreach($lines as $line){
				if(trim($line) != ""){
					list($f1, $f2, $f3, $f4) = explode(':', $line);
					if($f1 == $group) return true;
				}
			}
		}
		return false;
	/*
	// Alternative implementation of the is_group function. Should be faster then the old one To be tested.
	function is_group($group) {
	$groupfile = '/etc/group';
	if(is_file($groupfile)) {
		$handle = fopen ($groupfile, "r");
		while (!feof($handle)) {
			$line = trim(fgets($handle, 4096));
			if($line != ""){
				$parts = explode(":", $line);
	        	if($parts[0] == $group) {
					fclose ($handle);
					return true;
				}
			}
		}
		fclose ($handle);
	}
	return false;
	}
	*/
	function root_group(){
		global $app;
		$group_datei = $this->server_conf['group_datei'];
		$groups = $app->file->no_comments($group_datei);
		$lines = explode("\n", $groups);
		if(is_array($lines)){
			foreach($lines as $line){
				if(trim($line) != ''){
					list($f1, $f2, $f3, $f4) = explode(':', $line);
					if($f3 == 0) return $f1;
				}
			}
		}
		return false;
	/**
	 * Get the groups of an user
	 *
	 */
	function get_user_groups($username){
		global $app;
		$user_groups = array();
		$group_datei = $this->server_conf['group_datei'];
		$groups = $app->file->no_comments($group_datei);
		$lines = explode("\n", $groups);
		if(is_array($lines)){
			foreach($lines as $line){
				if(trim($line) != ''){
					list($f1, $f2, $f3, $f4) = explode(':', $line);
					if(intval($f3) < intval($this->server_conf['groupid_von']) && trim($f1) != 'users'){
						$tmp_group_users = explode(',', str_replace(' ', '', $f4));
						if(in_array($username, $tmp_group_users) && trim($f1) != '') $user_groups[] = $f1;
						unset($tmp_group_users);
					}
				}
			}
		}
		if(!empty($user_groups)) return implode(',', $user_groups);
		return '';
	/**
	 * Get a user password
	 *
	 */
	function getpasswd($user){
		global $app;
		if($this->is_user($user)){
			$shadow_datei = $this->server_conf['shadow_datei'];
			$passwds = $app->file->no_comments($shadow_datei);
			$lines = explode("\n", $passwds);
			if(is_array($lines)){
				foreach($lines as $line){
					if(trim($line) != ''){
						list($f1, $f2, ) = explode(':', $line);
						if($f1 == $user) return $f2;
					}
				}
			}
		} else {
			return false;
		}
	/**
	 * Get the user from an user id
	 *
	 */
	function getuser($uid){
		global $app;
		$user_datei = $this->server_conf['passwd_datei'];
		$users = $app->file->no_comments($user_datei);
		$lines = explode("\n", $users);
		if(is_array($lines)){
			foreach($lines as $line){
				if(trim($line) != ''){
					list($f1, $f2, $f3,) = explode(':', $line);
					if($f3 == $uid) return $f1;
				}
			}
		}
		return false;
	}





	/**
	 * Get the user id from an user
	 *
	 */
	function getuid($user){
		global $app;
		if($this->is_user($user)){
			$user_datei = $this->server_conf['passwd_datei'];
			$users = $app->file->no_comments($user_datei);
			$lines = explode("\n", $users);
			if(is_array($lines)){
				foreach($lines as $line){
					if(trim($line) != ''){
						list($f1, $f2, $f3, ) = explode(':', $line);
						if($f1 == $user) return $f3;
					}
				}
			}
		} else {
			return false;
		}
	/**
	 * Get the group from a group id
	 *
	 */
	function getgroup($gid){
		global $app;
		$group_datei = $this->server_conf['group_datei'];
		$groups = $app->file->no_comments($group_datei);
		$lines = explode("\n", $groups);
		if(is_array($lines)){
			foreach($lines as $line){
				if(trim($line) != ""){
					list($f1, $f2, $f3, $f4) = explode(':', $line);
					if($f3 == $gid) return $f1;
				}
			}
		}
		return false;
	}





	/**
	 * Get the group id from an group
	 *
	 */
	function getgid($group){
		global $app;
		if($this->is_group($group)){
			$group_datei = $this->server_conf['group_datei'];
			$groups = $app->file->no_comments($group_datei);
			$lines = explode("\n", $groups);
			if(is_array($lines)){
				foreach($lines as $line){
					if(trim($line) != ""){
						list($f1, $f2, $f3, $f4) = explode(':', $line);
						if($f1 == $group) return $f3;
					}
				}
			}
		} else {
			return false;
		}
	 * Return info about a group by name
	 *
	 */
	function posix_getgrnam($group) {
		if(!function_exists('posix_getgrnam')){
			$group_datei = $this->server_conf['group_datei'];
			$cmd = 'grep -m 1 "^'.$group.':" '.$group_datei;
			exec($cmd, $output, $return_var);
			if($return_var != 0 || !$output[0]) return false;
			list($f1, $f2, $f3, $f4) = explode(':', $output[0]);
			$f2 = trim($f2);
			$f3 = trim($f3);
			$f4 = trim($f4);
			if($f4 != ''){
				$members = explode(',', $f4);
			} else {
				$members = array();
			}
			$group_details = array( 'name' => $group,
				'passwd' => $f2,
				'members' => $members,
				'gid' => $f3);
			return $group_details;
		} else {
			return posix_getgrnam($group);
		}
	/**
	 * Get all information from a user
	 *
	 */
	function get_user_attributes($user){
		global $app;
		if($this->is_user($user)){
			$user_datei = $this->server_conf['passwd_datei'];
			$users = $app->file->no_comments($user_datei);
			$lines = explode("\n", $users);
			if(is_array($lines)){
				foreach($lines as $line){
					if(trim($line) != ''){
						list($f1, $f2, $f3, $f4, $f5, $f6, $f7) = explode(':', $line);
						if($f1 == $user){
							$user_attr['username'] = $f1;
							$user_attr['x'] = $f2;
							$user_attr['uid'] = $f3;
							$user_attr['gid'] = $f4;
							$user_attr['name'] = $f5;
							$user_attr['homedir'] = $f6;
							$user_attr['shell'] = $f7;
							return $user_attr;
						}
					}
				}
			}
		} else {
			return false;
		}
	function chown($file, $owner, $allow_symlink = false){
		global $app;
		if($allow_symlink == false && $this->checkpath($file) == false) {
			$app->log("Action aborted, file is a symlink: $file", LOGLEVEL_WARN);
		if(file_exists($file)) {
			if(@chown($file, $owner)) {
				return true;
			} else {
				$app->log("chown failed: $file : $owner", LOGLEVEL_DEBUG);
				return false;
			}
		}
	function chgrp($file, $group = '', $allow_symlink = false){
		global $app;
		if($allow_symlink == false && $this->checkpath($file) == false) {
			$app->log("Action aborted, file is a symlink: $file", LOGLEVEL_WARN);
		if(file_exists($file)) {
			if(@chgrp($file, $group)) {
				return true;
			} else {
				$app->log("chgrp failed: $file : $group", LOGLEVEL_DEBUG);
				return false;
			}
		}
	//* Change the mode of a file
	function chmod($file, $mode, $allow_symlink = false) {
		if($allow_symlink == false && $this->checkpath($file) == false) {
			$app->log("Action aborted, file is a symlink: $file", LOGLEVEL_WARN);
		if(@chmod($file, $mode)) {
			return true;
		} else {
			$app->log("chmod failed: $file : $mode", LOGLEVEL_DEBUG);
	function file_put_contents($filename, $data, $allow_symlink = false) {
		if($allow_symlink == false && $this->checkpath($filename) == false) {
			$app->log("Action aborted, file is a symlink: $filename", LOGLEVEL_WARN);
		if(file_exists($filename)) unlink($filename);
		return file_put_contents($filename, $data);
	}
	function file_get_contents($filename, $allow_symlink = false) {
		if($allow_symlink == false && $this->checkpath($filename) == false) {
			$app->log("Action aborted, file is a symlink: $filename", LOGLEVEL_WARN);
		return file_get_contents($filename, $data);
	function rename($filename, $new_filename, $allow_symlink = false) {
		if($allow_symlink == false && $this->checkpath($filename) == false) {
			$app->log("Action aborted, file is a symlink: $filename", LOGLEVEL_WARN);
			return false;
		}
		return rename($filename, $new_filename);
	}
	function mkdir($dirname, $allow_symlink = false, $mode = 0777, $recursive = false) {
		if($allow_symlink == false && $this->checkpath($dirname) == false) {
			$app->log("Action aborted, file is a symlink: $dirname", LOGLEVEL_WARN);
		if(@mkdir($dirname, $mode, $recursive)) {
			$app->log("mkdir failed: $dirname", LOGLEVEL_DEBUG);
	function unlink($filename) {
		if(file_exists($filename) || is_link($filename)) {
			return unlink($filename);
		}

	function copy($file1, $file2) {
		return copy($file1, $file2);
	function touch($file, $allow_symlink = false){
		global $app;
		if($allow_symlink == false && @file_exists($file) && $this->checkpath($file) == false) {
			$this->unlink($file);
		}
		if(@touch($file)) {
		} else {
			$app->log("touch failed: $file", LOGLEVEL_DEBUG);
	public function create_relative_link($f, $t) {
		global $app;

		// $from already exists
		$from = realpath($f);

		// realpath requires the traced file to exist - so, lets touch it first, then remove
		@$app->system->unlink($t); touch($t);
		$to = realpath($t);
		@$app->system->unlink($t);

		// Remove from the left side matching path elements from $from and $to
		// and get path elements counts
		$a1 = explode('/', $from); $a2 = explode('/', $to);
		for ($c = 0; $a1[$c] == $a2[$c]; $c++) {
			unset($a1[$c]); unset($a2[$c]);
		}
		$cfrom = implode('/', $a1);

		// Check if a path is fully a subpath of another - no way to create symlink in the case
		if (count($a1) == 0 || count($a2) == 0) return false;

		// Add ($cnt_to-1) number of "../" elements to left side of $cfrom
		for ($c = 0; $c < (count($a2)-1); $c++) { $cfrom = '../'.$cfrom; }
		if(strstr($to,'/etc/letsencrypt/archive/')) $to = str_replace('/etc/letsencrypt/archive/','/etc/letsencrypt/live/',$to);

		return symlink($cfrom, $to);
	}

	function checkpath($path) {
		$path = trim($path);
		//* We allow only absolute paths
		if(substr($path, 0, 1) != '/') return false;

		//* We allow only some characters in the path
		// * is allowed, for example it is part of wildcard certificates/keys: *.example.com.crt
		if(!preg_match('@^/[-a-zA-Z0-9_/.*]{1,}[~]?$@', $path)) return false;
		$path_parts = explode('/', $path);
		$testpath = '';
		foreach($path_parts as $p) {
			$testpath .= '/'.$p;
			if(is_link($testpath)) return false;
		}
	/**
	 * This function checks the free space for a given directory
	 * @param path check path
	 * @param limit min. free space in bytes
	 * @return bool - true when the the free space is above limit ohterwise false, opt. available disk-space
	function check_free_space($path, $limit = 0, &$free_space = 0) {
		$path = rtrim($path, '/');

		/**
		* Make sure that we have only existing directories in the path.

		* Given a file name instead of a directory, the behaviour of the disk_free_space
		function is unspecified and may differ between operating systems and PHP versions.
        */
		while(!is_dir($path) && $path != '/') $path = realpath(dirname($path));
		$free_space = disk_free_space($out);
		if (!$free_space) {
			$free_space = 0;
			return false;
		}
		if ($free_space >= $limit) {
	/**
	 * Add an user to a specific group
	 *
	 */
	function add_user_to_group($group, $user = 'admispconfig'){
		global $app;
		$group_file = $app->file->rf($this->server_conf['group_datei']);
		$group_file_lines = explode("\n", $group_file);
		foreach($group_file_lines as $group_file_line){
			list($group_name, $group_x, $group_id, $group_users) = explode(':', $group_file_line);
			if($group_name == $group){
				$group_users = explode(',', str_replace(' ', '', $group_users));
				if(!in_array($user, $group_users)){
					$group_users[] = $user;
				}
				$group_users = implode(',', $group_users);
				if(substr($group_users, 0, 1) == ',') $group_users = substr($group_users, 1);
				$group_file_line = $group_name.':'.$group_x.':'.$group_id.':'.$group_users;
			}