friendica/src/Util/Strings.php
2020-09-13 20:01:55 -04:00

540 lines
13 KiB
PHP

<?php
/**
* @copyright Copyright (C) 2020, Friendica
*
* @license GNU AGPL version 3 or any later version
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU Affero General Public License as
* published by the Free Software Foundation, either version 3 of the
* License, or (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU Affero General Public License for more details.
*
* You should have received a copy of the GNU Affero General Public License
* along with this program. If not, see <https://www.gnu.org/licenses/>.
*
*/
namespace Friendica\Util;
use Friendica\Content\ContactSelector;
use Friendica\Core\Logger;
/**
* This class handles string functions
*/
class Strings
{
/**
* Generates a pseudo-random string of hexadecimal characters
*
* @param int $size
* @return string
* @throws \Exception
*/
public static function getRandomHex($size = 64)
{
$byte_size = ceil($size / 2);
$bytes = random_bytes($byte_size);
$return = substr(bin2hex($bytes), 0, $size);
return $return;
}
/**
* Checks, if the given string is a valid hexadecimal code
*
* @param string $hexCode
*
* @return bool
*/
public static function isHex($hexCode)
{
return !empty($hexCode) ? @preg_match("/^[a-f0-9]{2,}$/i", $hexCode) && !(strlen($hexCode) & 1) : false;
}
/**
* This is our primary input filter.
*
* Use this on any text input where angle chars are not valid or permitted
* They will be replaced with safer brackets. This may be filtered further
* if these are not allowed either.
*
* @param string $string Input string
* @return string Filtered string
* @deprecated since 2020.09 Please use Smarty default HTML escaping for templates or htmlspecialchars() otherwise
*/
public static function escapeTags($string)
{
return str_replace(["<", ">"], ['[', ']'], $string);
}
/**
* Use this on "body" or "content" input where angle chars shouldn't be removed,
* and allow them to be safely displayed.
* @param string $string
*
* @return string
*/
public static function escapeHtml($string)
{
return htmlspecialchars($string, ENT_COMPAT, 'UTF-8', false);
}
/**
* Generate a string that's random, but usually pronounceable. Used to generate initial passwords
*
* @param int $len length
*
* @return string
*/
public static function getRandomName($len)
{
if ($len <= 0) {
return '';
}
$vowels = ['a', 'a', 'ai', 'au', 'e', 'e', 'e', 'ee', 'ea', 'i', 'ie', 'o', 'ou', 'u'];
if (mt_rand(0, 5) == 4) {
$vowels[] = 'y';
}
$cons = [
'b', 'bl', 'br',
'c', 'ch', 'cl', 'cr',
'd', 'dr',
'f', 'fl', 'fr',
'g', 'gh', 'gl', 'gr',
'h',
'j',
'k', 'kh', 'kl', 'kr',
'l',
'm',
'n',
'p', 'ph', 'pl', 'pr',
'qu',
'r', 'rh',
's', 'sc', 'sh', 'sm', 'sp', 'st',
't', 'th', 'tr',
'v',
'w', 'wh',
'x',
'z', 'zh'
];
$midcons = [
'ck', 'ct', 'gn', 'ld', 'lf', 'lm', 'lt', 'mb', 'mm', 'mn', 'mp',
'nd', 'ng', 'nk', 'nt', 'rn', 'rp', 'rt'
];
$noend = [
'bl', 'br', 'cl', 'cr', 'dr', 'fl', 'fr', 'gl', 'gr',
'kh', 'kl', 'kr', 'mn', 'pl', 'pr', 'rh', 'tr', 'qu', 'wh', 'q'
];
$start = mt_rand(0, 2);
if ($start == 0) {
$table = $vowels;
} else {
$table = $cons;
}
$word = '';
for ($x = 0; $x < $len; $x++) {
$r = mt_rand(0, count($table) - 1);
$word .= $table[$r];
if ($table == $vowels) {
$table = array_merge($cons, $midcons);
} else {
$table = $vowels;
}
}
$word = substr($word, 0, $len);
foreach ($noend as $noe) {
$noelen = strlen($noe);
if ((strlen($word) > $noelen) && (substr($word, -$noelen) == $noe)) {
$word = self::getRandomName($len);
break;
}
}
return $word;
}
/**
* Translate and format the network name of a contact
*
* @param string $network Network name of the contact (e.g. dfrn, rss and so on)
* @param string $url The contact url
*
* @return string Formatted network name
* @throws \Friendica\Network\HTTPException\InternalServerErrorException
*/
public static function formatNetworkName($network, $url = '')
{
if ($network != '') {
if ($url != '') {
$network_name = '<a href="' . $url . '">' . ContactSelector::networkToName($network, $url) . '</a>';
} else {
$network_name = ContactSelector::networkToName($network);
}
return $network_name;
}
}
/**
* Remove indentation from a text
*
* @param string $text String to be transformed.
* @param string $chr Optional. Indentation tag. Default tab (\t).
* @param int $count Optional. Default null.
*
* @return string Transformed string.
*/
public static function deindent($text, $chr = "[\t ]", $count = NULL)
{
$lines = explode("\n", $text);
if (is_null($count)) {
$m = [];
$k = 0;
while ($k < count($lines) && strlen($lines[$k]) == 0) {
$k++;
}
preg_match("|^" . $chr . "*|", $lines[$k], $m);
$count = strlen($m[0]);
}
for ($k = 0; $k < count($lines); $k++) {
$lines[$k] = preg_replace("|^" . $chr . "{" . $count . "}|", "", $lines[$k]);
}
return implode("\n", $lines);
}
/**
* Get byte size returned in a Data Measurement (KB, MB, GB)
*
* @param int $bytes The number of bytes to be measured
* @param int $precision Optional. Default 2.
*
* @return string Size with measured units.
*/
public static function formatBytes($bytes, $precision = 2)
{
$units = ['B', 'KB', 'MB', 'GB', 'TB'];
$bytes = max($bytes, 0);
$pow = floor(($bytes ? log($bytes) : 0) / log(1024));
$pow = min($pow, count($units) - 1);
$bytes /= pow(1024, $pow);
return round($bytes, $precision) . ' ' . $units[$pow];
}
/**
* Protect percent characters in sprintf calls
*
* @param string $s String to transform.
*
* @return string Transformed string.
*/
public static function protectSprintf($s)
{
return str_replace('%', '%%', $s);
}
/**
* Base64 Encode URL and translate +/ to -_ Optionally strip padding.
*
* @param string $s URL to encode
* @param boolean $strip_padding Optional. Default false
*
* @return string Encoded URL
*/
public static function base64UrlEncode($s, $strip_padding = false)
{
$s = strtr(base64_encode($s), '+/', '-_');
if ($strip_padding) {
$s = str_replace('=', '', $s);
}
return $s;
}
/**
* Decode Base64 Encoded URL and translate -_ to +/
* @param string $s URL to decode
*
* @return string Decoded URL
* @throws \Exception
*/
public static function base64UrlDecode($s)
{
if (is_array($s)) {
Logger::log('base64url_decode: illegal input: ' . print_r(debug_backtrace(), true));
return $s;
}
/*
* // Placeholder for new rev of salmon which strips base64 padding.
* // PHP base64_decode handles the un-padded input without requiring this step
* // Uncomment if you find you need it.
*
* $l = strlen($s);
* if (!strpos($s,'=')) {
* $m = $l % 4;
* if ($m == 2)
* $s .= '==';
* if ($m == 3)
* $s .= '=';
* }
*
*/
return base64_decode(strtr($s, '-_', '+/'));
}
/**
* Normalize url
*
* @param string $url URL to be normalized.
*
* @return string Normalized URL.
*/
public static function normaliseLink($url)
{
$ret = str_replace(['https:', '//www.'], ['http:', '//'], $url);
return rtrim($ret, '/');
}
/**
* Normalize OpenID identity
*
* @param string $s OpenID Identity
*
* @return string normalized OpenId Identity
*/
public static function normaliseOpenID($s)
{
return trim(str_replace(['http://', 'https://'], ['', ''], $s), '/');
}
/**
* Compare two URLs to see if they are the same, but ignore
* slight but hopefully insignificant differences such as if one
* is https and the other isn't, or if one is www.something and
* the other isn't - and also ignore case differences.
*
* @param string $a first url
* @param string $b second url
* @return boolean True if the URLs match, otherwise False
*
*/
public static function compareLink($a, $b)
{
return (strcasecmp(self::normaliseLink($a), self::normaliseLink($b)) === 0);
}
/**
* Ensures the provided URI has its query string punctuation in order.
*
* @param string $uri
* @return string
*/
public static function ensureQueryParameter($uri)
{
if (strpos($uri, '?') === false && ($pos = strpos($uri, '&')) !== false) {
$uri = substr($uri, 0, $pos) . '?' . substr($uri, $pos + 1);
}
return $uri;
}
/**
* Check if the trimmed provided string is starting with one of the provided characters
*
* @param string $string
* @param array $chars
* @return bool
*/
public static function startsWithChars($string, array $chars)
{
$return = in_array(substr(trim($string), 0, 1), $chars);
return $return;
}
/**
* Check if the first string starts with the second
*
* @see http://maettig.com/code/php/php-performance-benchmarks.php#startswith
* @param string $string
* @param string $start
* @return bool
*/
public static function startsWith(string $string, string $start)
{
$return = substr_compare($string, $start, 0, strlen($start)) === 0;
return $return;
}
/**
* Checks if the first string ends with the second
*
* @see http://maettig.com/code/php/php-performance-benchmarks.php#endswith
* @param string $string
* @param string $end
* @return bool
*/
public static function endsWith(string $string, string $end)
{
$return = substr_compare($string, $end, -strlen($end)) === 0;
return $return;
}
/**
* Returns the regular expression string to match URLs in a given text
*
* @return string
* @see https://daringfireball.net/2010/07/improved_regex_for_matching_urls
*/
public static function autoLinkRegEx()
{
return '@
(?<![=\'\]"/]) # Not preceded by [, =, \', ], ", /
\b
( # Capture 1: entire matched URL
https?:// # http or https protocol
(?:
[^/\s\xA0`!()\[\]{};:\'",<>?«»“”‘’.] # Domain can\'t start with a .
[^/\s\xA0`!()\[\]{};:\'",<>?«»“”‘’]+ # Domain can\'t end with a .
\.
[^/\s\xA0`!()\[\]{};:\'".,<>?«»“”‘’]+/? # Followed by a slash
)
(?: # One or more:
[^\s\xA0()<>]+ # Run of non-space, non-()<>
| # or
\(([^\s\xA0()<>]+|(\([^\s()<>]+\)))*\) # balanced parens, up to 2 levels
| # or
[^\s\xA0`!()\[\]{};:\'".,<>?«»“”‘’] # not a space or one of these punct chars
)*
)@xiu';
}
/**
* Ensures a single path item doesn't contain any path-traversing characters
*
* @see https://stackoverflow.com/a/46097713
* @param string $pathItem
* @return string
*/
public static function sanitizeFilePathItem($pathItem)
{
$pathItem = str_replace('/', '_', $pathItem);
$pathItem = str_replace('\\', '_', $pathItem);
$pathItem = str_replace(DIRECTORY_SEPARATOR, '_', $pathItem); // In case it does not equal the standard values
return $pathItem;
}
/**
* Multi-byte safe implementation of substr_replace where $start and $length are character offset and count rather
* than byte offset and counts.
*
* Depends on mbstring, use default encoding.
*
* @param string $string
* @param string $replacement
* @param int $start
* @param int|null $length
* @return string
* @see substr_replace()
*/
public static function substringReplace(string $string, string $replacement, int $start, int $length = null)
{
$string_length = mb_strlen($string);
$length = $length ?? $string_length;
if ($start < 0) {
$start = max(0, $string_length + $start);
} else if ($start > $string_length) {
$start = $string_length;
}
if ($length < 0) {
$length = max(0, $string_length - $start + $length);
} else if ($length > $string_length) {
$length = $string_length;
}
if (($start + $length) > $string_length) {
$length = $string_length - $start;
}
return mb_substr($string, 0, $start) . $replacement . mb_substr($string, $start + $length, $string_length - $start - $length);
}
/**
* Perform a custom function on a text after having escaped blocks matched by the provided regular expressions.
* Only full matches are used, capturing group are ignored.
*
* To change the provided text, the callback function needs to return it and this function will return the modified
* version as well after having restored the escaped blocks.
*
* @param string $text
* @param string $regex
* @param callable $callback
* @return string
* @throws \Exception
*/
public static function performWithEscapedBlocks(string $text, string $regex, callable $callback)
{
// Enables nested use
$executionId = random_int(PHP_INT_MAX / 10, PHP_INT_MAX);
$blocks = [];
$text = preg_replace_callback($regex,
function ($matches) use ($executionId, &$blocks) {
$return = '«block-' . $executionId . '-' . count($blocks) . '»';
$blocks[] = $matches[0];
return $return;
},
$text
);
$text = $callback($text) ?? '';
// Restore code blocks
$text = preg_replace_callback('/«block-' . $executionId . '-([0-9]+)»/iU',
function ($matches) use ($blocks) {
$return = $matches[0];
if (isset($blocks[intval($matches[1])])) {
$return = $blocks[$matches[1]];
}
return $return;
},
$text
);
return $text;
}
}