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roundcubemail/program/lib/Roundcube/rcube_utils.php

922 lines
29 KiB
PHTML

<?php
/*
+-----------------------------------------------------------------------+
| This file is part of the Roundcube Webmail client |
| Copyright (C) 2008-2012, The Roundcube Dev Team |
| Copyright (C) 2011-2012, Kolab Systems AG |
| |
| Licensed under the GNU General Public License version 3 or |
| any later version with exceptions for skins & plugins. |
| See the README file for a full license statement. |
| |
| PURPOSE: |
| Utility class providing common functions |
+-----------------------------------------------------------------------+
| Author: Thomas Bruederli <roundcube@gmail.com> |
| Author: Aleksander Machniak <alec@alec.pl> |
+-----------------------------------------------------------------------+
*/
/**
* Utility class providing common functions
*
* @package Framework
* @subpackage Utils
*/
class rcube_utils
{
// define constants for input reading
const INPUT_GET = 0x0101;
const INPUT_POST = 0x0102;
const INPUT_GPC = 0x0103;
/**
* Helper method to set a cookie with the current path and host settings
*
* @param string Cookie name
* @param string Cookie value
* @param string Expiration time
*/
public static function setcookie($name, $value, $exp = 0)
{
if (headers_sent()) {
return;
}
$cookie = session_get_cookie_params();
$secure = $cookie['secure'] || self::https_check();
setcookie($name, $value, $exp, $cookie['path'], $cookie['domain'], $secure, true);
}
/**
* E-mail address validation.
*
* @param string $email Email address
* @param boolean $dns_check True to check dns
*
* @return boolean True on success, False if address is invalid
*/
public static function check_email($email, $dns_check=true)
{
// Check for invalid characters
if (preg_match('/[\x00-\x1F\x7F-\xFF]/', $email)) {
return false;
}
// Check for length limit specified by RFC 5321 (#1486453)
if (strlen($email) > 254) {
return false;
}
$email_array = explode('@', $email);
// Check that there's one @ symbol
if (count($email_array) < 2) {
return false;
}
$domain_part = array_pop($email_array);
$local_part = implode('@', $email_array);
// from PEAR::Validate
$regexp = '&^(?:
("\s*(?:[^"\f\n\r\t\v\b\s]+\s*)+")| #1 quoted name
([-\w!\#\$%\&\'*+~/^`|{}=]+(?:\.[-\w!\#\$%\&\'*+~/^`|{}=]+)*)) #2 OR dot-atom (RFC5322)
$&xi';
if (!preg_match($regexp, $local_part)) {
return false;
}
// Validate domain part
if (preg_match('/^\[((IPv6:[0-9a-f:.]+)|([0-9.]+))\]$/i', $domain_part, $matches)) {
return self::check_ip(preg_replace('/^IPv6:/i', '', $matches[1])); // valid IPv4 or IPv6 address
}
else {
// If not an IP address
$domain_array = explode('.', $domain_part);
// Not enough parts to be a valid domain
if (sizeof($domain_array) < 2) {
return false;
}
foreach ($domain_array as $part) {
if (!preg_match('/^(([A-Za-z0-9][A-Za-z0-9-]{0,61}[A-Za-z0-9])|([A-Za-z0-9]))$/', $part)) {
return false;
}
}
// last domain part
if (preg_match('/[^a-zA-Z]/', array_pop($domain_array))) {
return false;
}
$rcube = rcube::get_instance();
if (!$dns_check || !$rcube->config->get('email_dns_check')) {
return true;
}
if (strtoupper(substr(PHP_OS, 0, 3)) == 'WIN' && version_compare(PHP_VERSION, '5.3.0', '<')) {
$lookup = array();
@exec("nslookup -type=MX " . escapeshellarg($domain_part) . " 2>&1", $lookup);
foreach ($lookup as $line) {
if (strpos($line, 'MX preference')) {
return true;
}
}
return false;
}
// find MX record(s)
if (!function_exists('getmxrr') || getmxrr($domain_part, $mx_records)) {
return true;
}
// find any DNS record
if (!function_exists('checkdnsrr') || checkdnsrr($domain_part, 'ANY')) {
return true;
}
}
return false;
}
/**
* Validates IPv4 or IPv6 address
*
* @param string $ip IP address in v4 or v6 format
*
* @return bool True if the address is valid
*/
public static function check_ip($ip)
{
// IPv6, but there's no build-in IPv6 support
if (strpos($ip, ':') !== false && !defined('AF_INET6')) {
$parts = explode(':', $domain_part);
$count = count($parts);
if ($count > 8 || $count < 2) {
return false;
}
foreach ($parts as $idx => $part) {
$length = strlen($part);
if (!$length) {
// there can be only one ::
if ($found_empty) {
return false;
}
$found_empty = true;
}
// last part can be an IPv4 address
else if ($idx == $count - 1) {
if (!preg_match('/^[0-9a-f]{1,4}$/i', $part)) {
return @inet_pton($part) !== false;
}
}
else if (!preg_match('/^[0-9a-f]{1,4}$/i', $part)) {
return false;
}
}
return true;
}
return @inet_pton($ip) !== false;
}
/**
* Check whether the HTTP referer matches the current request
*
* @return boolean True if referer is the same host+path, false if not
*/
public static function check_referer()
{
$uri = parse_url($_SERVER['REQUEST_URI']);
$referer = parse_url(self::request_header('Referer'));
return $referer['host'] == self::request_header('Host') && $referer['path'] == $uri['path'];
}
/**
* Replacing specials characters to a specific encoding type
*
* @param string Input string
* @param string Encoding type: text|html|xml|js|url
* @param string Replace mode for tags: show|replace|remove
* @param boolean Convert newlines
*
* @return string The quoted string
*/
public static function rep_specialchars_output($str, $enctype = '', $mode = '', $newlines = true)
{
static $html_encode_arr = false;
static $js_rep_table = false;
static $xml_rep_table = false;
if (!is_string($str)) {
$str = strval($str);
}
// encode for HTML output
if ($enctype == 'html') {
if (!$html_encode_arr) {
$html_encode_arr = get_html_translation_table(HTML_SPECIALCHARS);
unset($html_encode_arr['?']);
}
$encode_arr = $html_encode_arr;
// don't replace quotes and html tags
if ($mode == 'show' || $mode == '') {
$ltpos = strpos($str, '<');
if ($ltpos !== false && strpos($str, '>', $ltpos) !== false) {
unset($encode_arr['"']);
unset($encode_arr['<']);
unset($encode_arr['>']);
unset($encode_arr['&']);
}
}
else if ($mode == 'remove') {
$str = strip_tags($str);
}
$out = strtr($str, $encode_arr);
return $newlines ? nl2br($out) : $out;
}
// if the replace tables for XML and JS are not yet defined
if ($js_rep_table === false) {
$js_rep_table = $xml_rep_table = array();
$xml_rep_table['&'] = '&amp;';
// can be increased to support more charsets
for ($c=160; $c<256; $c++) {
$xml_rep_table[chr($c)] = "&#$c;";
}
$xml_rep_table['"'] = '&quot;';
$js_rep_table['"'] = '\\"';
$js_rep_table["'"] = "\\'";
$js_rep_table["\\"] = "\\\\";
// Unicode line and paragraph separators (#1486310)
$js_rep_table[chr(hexdec(E2)).chr(hexdec(80)).chr(hexdec(A8))] = '&#8232;';
$js_rep_table[chr(hexdec(E2)).chr(hexdec(80)).chr(hexdec(A9))] = '&#8233;';
}
// encode for javascript use
if ($enctype == 'js') {
return preg_replace(array("/\r?\n/", "/\r/", '/<\\//'), array('\n', '\n', '<\\/'), strtr($str, $js_rep_table));
}
// encode for plaintext
if ($enctype == 'text') {
return str_replace("\r\n", "\n", $mode=='remove' ? strip_tags($str) : $str);
}
if ($enctype == 'url') {
return rawurlencode($str);
}
// encode for XML
if ($enctype == 'xml') {
return strtr($str, $xml_rep_table);
}
// no encoding given -> return original string
return $str;
}
/**
* Read input value and convert it for internal use
* Performs stripslashes() and charset conversion if necessary
*
* @param string Field name to read
* @param int Source to get value from (GPC)
* @param boolean Allow HTML tags in field value
* @param string Charset to convert into
*
* @return string Field value or NULL if not available
*/
public static function get_input_value($fname, $source, $allow_html=FALSE, $charset=NULL)
{
$value = NULL;
if ($source == self::INPUT_GET) {
if (isset($_GET[$fname])) {
$value = $_GET[$fname];
}
}
else if ($source == self::INPUT_POST) {
if (isset($_POST[$fname])) {
$value = $_POST[$fname];
}
}
else if ($source == self::INPUT_GPC) {
if (isset($_POST[$fname])) {
$value = $_POST[$fname];
}
else if (isset($_GET[$fname])) {
$value = $_GET[$fname];
}
else if (isset($_COOKIE[$fname])) {
$value = $_COOKIE[$fname];
}
}
return self::parse_input_value($value, $allow_html, $charset);
}
/**
* Parse/validate input value. See self::get_input_value()
* Performs stripslashes() and charset conversion if necessary
*
* @param string Input value
* @param boolean Allow HTML tags in field value
* @param string Charset to convert into
*
* @return string Parsed value
*/
public static function parse_input_value($value, $allow_html=FALSE, $charset=NULL)
{
global $OUTPUT;
if (empty($value)) {
return $value;
}
if (is_array($value)) {
foreach ($value as $idx => $val) {
$value[$idx] = self::parse_input_value($val, $allow_html, $charset);
}
return $value;
}
// strip single quotes if magic_quotes_sybase is enabled
if (ini_get('magic_quotes_sybase')) {
$value = str_replace("''", "'", $value);
}
// strip slashes if magic_quotes enabled
else if (get_magic_quotes_gpc() || get_magic_quotes_runtime()) {
$value = stripslashes($value);
}
// remove HTML tags if not allowed
if (!$allow_html) {
$value = strip_tags($value);
}
$output_charset = is_object($OUTPUT) ? $OUTPUT->get_charset() : null;
// remove invalid characters (#1488124)
if ($output_charset == 'UTF-8') {
$value = rcube_charset::clean($value);
}
// convert to internal charset
if ($charset && $output_charset) {
$value = rcube_charset::convert($value, $output_charset, $charset);
}
return $value;
}
/**
* Convert array of request parameters (prefixed with _)
* to a regular array with non-prefixed keys.
*
* @param int $mode Source to get value from (GPC)
* @param string $ignore PCRE expression to skip parameters by name
*
* @return array Hash array with all request parameters
*/
public static function request2param($mode = null, $ignore = 'task|action')
{
$out = array();
$src = $mode == self::INPUT_GET ? $_GET : ($mode == self::INPUT_POST ? $_POST : $_REQUEST);
foreach ($src as $key => $value) {
$fname = $key[0] == '_' ? substr($key, 1) : $key;
if ($ignore && !preg_match('/^(' . $ignore . ')$/', $fname)) {
$out[$fname] = self::get_input_value($key, $mode);
}
}
return $out;
}
/**
* Convert the given string into a valid HTML identifier
* Same functionality as done in app.js with rcube_webmail.html_identifier()
*/
public static function html_identifier($str, $encode=false)
{
if ($encode) {
return rtrim(strtr(base64_encode($str), '+/', '-_'), '=');
}
else {
return asciiwords($str, true, '_');
}
}
/**
* Replace all css definitions with #container [def]
* and remove css-inlined scripting
*
* @param string CSS source code
* @param string Container ID to use as prefix
*
* @return string Modified CSS source
*/
public static function mod_css_styles($source, $container_id, $allow_remote=false)
{
$last_pos = 0;
$replacements = new rcube_string_replacer;
// ignore the whole block if evil styles are detected
$source = self::xss_entity_decode($source);
$stripped = preg_replace('/[^a-z\(:;]/i', '', $source);
$evilexpr = 'expression|behavior|javascript:|import[^a]' . (!$allow_remote ? '|url\(' : '');
if (preg_match("/$evilexpr/i", $stripped)) {
return '/* evil! */';
}
// cut out all contents between { and }
while (($pos = strpos($source, '{', $last_pos)) && ($pos2 = strpos($source, '}', $pos))) {
$styles = substr($source, $pos+1, $pos2-($pos+1));
// check every line of a style block...
if ($allow_remote) {
$a_styles = preg_split('/;[\r\n]*/', $styles, -1, PREG_SPLIT_NO_EMPTY);
foreach ($a_styles as $line) {
$stripped = preg_replace('/[^a-z\(:;]/i', '', $line);
// ... and only allow strict url() values
$regexp = '!url\s*\([ "\'](https?:)//[a-z0-9/._+-]+["\' ]\)!Uims';
if (stripos($stripped, 'url(') && !preg_match($regexp, $line)) {
$a_styles = array('/* evil! */');
break;
}
}
$styles = join(";\n", $a_styles);
}
$key = $replacements->add($styles);
$source = substr($source, 0, $pos+1)
. $replacements->get_replacement($key)
. substr($source, $pos2, strlen($source)-$pos2);
$last_pos = $pos+2;
}
// remove html comments and add #container to each tag selector.
// also replace body definition because we also stripped off the <body> tag
$styles = preg_replace(
array(
'/(^\s*<!--)|(-->\s*$)/',
'/(^\s*|,\s*|\}\s*)([a-z0-9\._#\*][a-z0-9\.\-_]*)/im',
'/'.preg_quote($container_id, '/').'\s+body/i',
),
array(
'',
"\\1#$container_id \\2",
$container_id,
),
$source);
// put block contents back in
$styles = $replacements->resolve($styles);
return $styles;
}
/**
* Generate CSS classes from mimetype and filename extension
*
* @param string $mimetype Mimetype
* @param string $filename Filename
*
* @return string CSS classes separated by space
*/
public static function file2class($mimetype, $filename)
{
list($primary, $secondary) = explode('/', $mimetype);
$classes = array($primary ? $primary : 'unknown');
if ($secondary) {
$classes[] = $secondary;
}
if (preg_match('/\.([a-z0-9]+)$/i', $filename, $m)) {
$classes[] = $m[1];
}
return strtolower(join(" ", $classes));
}
/**
* Decode escaped entities used by known XSS exploits.
* See http://downloads.securityfocus.com/vulnerabilities/exploits/26800.eml for examples
*
* @param string CSS content to decode
*
* @return string Decoded string
*/
public static function xss_entity_decode($content)
{
$out = html_entity_decode(html_entity_decode($content));
$out = preg_replace_callback('/\\\([0-9a-f]{4})/i',
array(self, 'xss_entity_decode_callback'), $out);
$out = preg_replace('#/\*.*\*/#Ums', '', $out);
return $out;
}
/**
* preg_replace_callback callback for xss_entity_decode
*
* @param array $matches Result from preg_replace_callback
*
* @return string Decoded entity
*/
public static function xss_entity_decode_callback($matches)
{
return chr(hexdec($matches[1]));
}
/**
* Check if we can process not exceeding memory_limit
*
* @param integer Required amount of memory
*
* @return boolean True if memory won't be exceeded, False otherwise
*/
public static function mem_check($need)
{
$mem_limit = parse_bytes(ini_get('memory_limit'));
$memory = function_exists('memory_get_usage') ? memory_get_usage() : 16*1024*1024; // safe value: 16MB
return $mem_limit > 0 && $memory + $need > $mem_limit ? false : true;
}
/**
* Check if working in SSL mode
*
* @param integer $port HTTPS port number
* @param boolean $use_https Enables 'use_https' option checking
*
* @return boolean
*/
public static function https_check($port=null, $use_https=true)
{
global $RCMAIL;
if (!empty($_SERVER['HTTPS']) && strtolower($_SERVER['HTTPS']) != 'off') {
return true;
}
if (!empty($_SERVER['HTTP_X_FORWARDED_PROTO']) && strtolower($_SERVER['HTTP_X_FORWARDED_PROTO']) == 'https') {
return true;
}
if ($port && $_SERVER['SERVER_PORT'] == $port) {
return true;
}
if ($use_https && isset($RCMAIL) && $RCMAIL->config->get('use_https')) {
return true;
}
return false;
}
/**
* Replaces hostname variables.
*
* @param string $name Hostname
* @param string $host Optional IMAP hostname
*
* @return string Hostname
*/
public static function parse_host($name, $host = '')
{
// %n - host
$n = preg_replace('/:\d+$/', '', $_SERVER['SERVER_NAME']);
// %t - host name without first part, e.g. %n=mail.domain.tld, %t=domain.tld
13 years ago
$t = preg_replace('/^[^\.]+\./', '', $n);
// %d - domain name without first part
$d = preg_replace('/^[^\.]+\./', '', $_SERVER['HTTP_HOST']);
// %h - IMAP host
$h = $_SESSION['storage_host'] ? $_SESSION['storage_host'] : $host;
// %z - IMAP domain without first part, e.g. %h=imap.domain.tld, %z=domain.tld
$z = preg_replace('/^[^\.]+\./', '', $h);
// %s - domain name after the '@' from e-mail address provided at login screen. Returns FALSE if an invalid email is provided
if (strpos($name, '%s') !== false) {
$user_email = self::get_input_value('_user', self::INPUT_POST);
13 years ago
$user_email = self::idn_convert($user_email, true);
$matches = preg_match('/(.*)@([a-z0-9\.\-\[\]\:]+)/i', $user_email, $s);
if ($matches < 1 || filter_var($s[1]."@".$s[2], FILTER_VALIDATE_EMAIL) === false) {
return false;
}
}
$name = str_replace(array('%n', '%t', '%d', '%h', '%z', '%s'), array($n, $t, $d, $h, $z, $s[2]), $name);
return $name;
}
/**
* Returns remote IP address and forwarded addresses if found
*
* @return string Remote IP address(es)
*/
public static function remote_ip()
{
$address = $_SERVER['REMOTE_ADDR'];
// append the NGINX X-Real-IP header, if set
if (!empty($_SERVER['HTTP_X_REAL_IP'])) {
$remote_ip[] = 'X-Real-IP: ' . $_SERVER['HTTP_X_REAL_IP'];
}
// append the X-Forwarded-For header, if set
if (!empty($_SERVER['HTTP_X_FORWARDED_FOR'])) {
$remote_ip[] = 'X-Forwarded-For: ' . $_SERVER['HTTP_X_FORWARDED_FOR'];
}
if (!empty($remote_ip)) {
$address .= '(' . implode(',', $remote_ip) . ')';
}
return $address;
}
/**
* Read a specific HTTP request header.
*
* @param string $name Header name
*
* @return mixed Header value or null if not available
*/
public static function request_header($name)
{
if (function_exists('getallheaders')) {
$hdrs = array_change_key_case(getallheaders(), CASE_UPPER);
$key = strtoupper($name);
}
else {
$key = 'HTTP_' . strtoupper(strtr($name, '-', '_'));
$hdrs = array_change_key_case($_SERVER, CASE_UPPER);
}
return $hdrs[$key];
}
/**
* Explode quoted string
*
* @param string Delimiter expression string for preg_match()
* @param string Input string
*
* @return array String items
*/
public static function explode_quoted_string($delimiter, $string)
{
$result = array();
$strlen = strlen($string);
for ($q=$p=$i=0; $i < $strlen; $i++) {
if ($string[$i] == "\"" && $string[$i-1] != "\\") {
$q = $q ? false : true;
}
else if (!$q && preg_match("/$delimiter/", $string[$i])) {
$result[] = substr($string, $p, $i - $p);
$p = $i + 1;
}
}
$result[] = (string) substr($string, $p);
return $result;
}
/**
* Improved equivalent to strtotime()
*
* @param string $date Date string
*
* @return int Unix timestamp
*/
public static function strtotime($date)
{
// check for MS Outlook vCard date format YYYYMMDD
if (preg_match('/^([12][90]\d\d)([01]\d)(\d\d)$/', trim($date), $matches)) {
return mktime(0,0,0, intval($matches[2]), intval($matches[3]), intval($matches[1]));
}
else if (is_numeric($date)) {
return $date;
}
// support non-standard "GMTXXXX" literal
$date = preg_replace('/GMT\s*([+-][0-9]+)/', '\\1', $date);
// if date parsing fails, we have a date in non-rfc format.
// remove token from the end and try again
while ((($ts = @strtotime($date)) === false) || ($ts < 0)) {
$d = explode(' ', $date);
array_pop($d);
if (!$d) {
break;
}
$date = implode(' ', $d);
}
return $ts;
}
/*
* Idn_to_ascii wrapper.
* Intl/Idn modules version of this function doesn't work with e-mail address
*/
public static function idn_to_ascii($str)
{
return self::idn_convert($str, true);
}
/*
* Idn_to_ascii wrapper.
* Intl/Idn modules version of this function doesn't work with e-mail address
*/
public static function idn_to_utf8($str)
{
return self::idn_convert($str, false);
}
public static function idn_convert($input, $is_utf=false)
{
if ($at = strpos($input, '@')) {
$user = substr($input, 0, $at);
$domain = substr($input, $at+1);
}
else {
$domain = $input;
}
$domain = $is_utf ? idn_to_ascii($domain) : idn_to_utf8($domain);
if ($domain === false) {
return '';
}
return $at ? $user . '@' . $domain : $domain;
}
/**
* Split the given string into word tokens
*
* @param string Input to tokenize
* @return array List of tokens
*/
public static function tokenize_string($str)
{
return explode(" ", preg_replace(
array('/[\s;\/+-]+/i', '/(\d)[-.\s]+(\d)/', '/\s\w{1,3}\s/u'),
array(' ', '\\1\\2', ' '),
$str));
}
/**
* Normalize the given string for fulltext search.
* Currently only optimized for Latin-1 characters; to be extended
*
* @param string Input string (UTF-8)
* @param boolean True to return list of words as array
* @return mixed Normalized string or a list of normalized tokens
*/
public static function normalize_string($str, $as_array = false)
{
// split by words
$arr = self::tokenize_string($str);
foreach ($arr as $i => $part) {
if (utf8_encode(utf8_decode($part)) == $part) { // is latin-1 ?
$arr[$i] = utf8_encode(strtr(strtolower(strtr(utf8_decode($part),
'ÇçäâàåéêëèïîìÅÉöôòüûùÿøØáíóúñÑÁÂÀãÃÊËÈÍÎÏÓÔõÕÚÛÙýÝ',
'ccaaaaeeeeiiiaeooouuuyooaiounnaaaaaeeeiiioooouuuyy')),
array('ß' => 'ss', 'ae' => 'a', 'oe' => 'o', 'ue' => 'u')));
}
else
$arr[$i] = mb_strtolower($part);
}
return $as_array ? $arr : join(" ", $arr);
}
/**
* Parse commandline arguments into a hash array
*
* @param array $aliases Argument alias names
*
* @return array Argument values hash
*/
public static function get_opt($aliases = array())
{
$args = array();
for ($i=1; $i < count($_SERVER['argv']); $i++) {
$arg = $_SERVER['argv'][$i];
$value = true;
$key = null;
if ($arg[0] == '-') {
$key = preg_replace('/^-+/', '', $arg);
$sp = strpos($arg, '=');
if ($sp > 0) {
$key = substr($key, 0, $sp - 2);
$value = substr($arg, $sp+1);
}
else if (strlen($_SERVER['argv'][$i+1]) && $_SERVER['argv'][$i+1][0] != '-') {
$value = $_SERVER['argv'][++$i];
}
$args[$key] = is_string($value) ? preg_replace(array('/^["\']/', '/["\']$/'), '', $value) : $value;
}
else {
$args[] = $arg;
}
if ($alias = $aliases[$key]) {
$args[$alias] = $args[$key];
}
}
return $args;
}
/**
* Safe password prompt for command line
* from http://blogs.sitepoint.com/2009/05/01/interactive-cli-password-prompt-in-php/
*
* @return string Password
*/
public static function prompt_silent($prompt = "Password:")
{
if (preg_match('/^win/i', PHP_OS)) {
$vbscript = sys_get_temp_dir() . 'prompt_password.vbs';
$vbcontent = 'wscript.echo(InputBox("' . addslashes($prompt) . '", "", "password here"))';
file_put_contents($vbscript, $vbcontent);
$command = "cscript //nologo " . escapeshellarg($vbscript);
$password = rtrim(shell_exec($command));
unlink($vbscript);
return $password;
}
else {
$command = "/usr/bin/env bash -c 'echo OK'";
if (rtrim(shell_exec($command)) !== 'OK') {
echo $prompt;
$pass = trim(fgets(STDIN));
echo chr(8)."\r" . $prompt . str_repeat("*", strlen($pass))."\n";
return $pass;
}
$command = "/usr/bin/env bash -c 'read -s -p \"" . addslashes($prompt) . "\" mypassword && echo \$mypassword'";
$password = rtrim(shell_exec($command));
echo "\n";
return $password;
}
}
/**
* Find out if the string content means true or false
*
* @param string $str Input value
*
* @return boolean Boolean value
*/
public static function get_boolean($str)
{
$str = strtolower($str);
return !in_array($str, array('false', '0', 'no', 'off', 'nein', ''), true);
}
}