Newer
Older
Steven Wittens
committed
<?php
/**
* Indicates an error during check for PHP unicode support.
*/
Steven Wittens
committed
define('UNICODE_ERROR', -1);
/**
* Indicates that standard PHP (emulated) unicode support is being used.
*/
Steven Wittens
committed
define('UNICODE_SINGLEBYTE', 0);
/**
* Indicates that full unicode support with the PHP mbstring extension is being
* used.
*/
Steven Wittens
committed
define('UNICODE_MULTIBYTE', 1);
Dries Buytaert
committed
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
/**
* Matches Unicode characters that are word boundaries.
*
* @see http://unicode.org/glossary
*
* Characters with the following General_category (gc) property values are used
* as word boundaries. While this does not fully conform to the Word Boundaries
* algorithm described in http://unicode.org/reports/tr29, as PCRE does not
* contain the Word_Break property table, this simpler algorithm has to do.
* - Cc, Cf, Cn, Co, Cs: Other.
* - Pc, Pd, Pe, Pf, Pi, Po, Ps: Punctuation.
* - Sc, Sk, Sm, So: Symbols.
* - Zl, Zp, Zs: Separators.
*
* Non-boundary characters include the following General_category (gc) property
* values:
* - Ll, Lm, Lo, Lt, Lu: Letters.
* - Mc, Me, Mn: Combining Marks.
* - Nd, Nl, No: Numbers.
*
* Note that the PCRE property matcher is not used because we wanted to be
* compatible with Unicode 5.2.0 regardless of the PCRE version used (and any
* bugs in PCRE property tables).
*/
define('PREG_CLASS_UNICODE_WORD_BOUNDARY',
'\x{0}-\x{2F}\x{3A}-\x{40}\x{5B}-\x{60}\x{7B}-\x{A9}\x{AB}-\x{B1}\x{B4}' .
'\x{B6}-\x{B8}\x{BB}\x{BF}\x{D7}\x{F7}\x{2C2}-\x{2C5}\x{2D2}-\x{2DF}' .
'\x{2E5}-\x{2EB}\x{2ED}\x{2EF}-\x{2FF}\x{375}\x{37E}-\x{385}\x{387}\x{3F6}' .
'\x{482}\x{55A}-\x{55F}\x{589}-\x{58A}\x{5BE}\x{5C0}\x{5C3}\x{5C6}' .
'\x{5F3}-\x{60F}\x{61B}-\x{61F}\x{66A}-\x{66D}\x{6D4}\x{6DD}\x{6E9}' .
'\x{6FD}-\x{6FE}\x{700}-\x{70F}\x{7F6}-\x{7F9}\x{830}-\x{83E}' .
'\x{964}-\x{965}\x{970}\x{9F2}-\x{9F3}\x{9FA}-\x{9FB}\x{AF1}\x{B70}' .
'\x{BF3}-\x{BFA}\x{C7F}\x{CF1}-\x{CF2}\x{D79}\x{DF4}\x{E3F}\x{E4F}' .
'\x{E5A}-\x{E5B}\x{F01}-\x{F17}\x{F1A}-\x{F1F}\x{F34}\x{F36}\x{F38}' .
'\x{F3A}-\x{F3D}\x{F85}\x{FBE}-\x{FC5}\x{FC7}-\x{FD8}\x{104A}-\x{104F}' .
'\x{109E}-\x{109F}\x{10FB}\x{1360}-\x{1368}\x{1390}-\x{1399}\x{1400}' .
'\x{166D}-\x{166E}\x{1680}\x{169B}-\x{169C}\x{16EB}-\x{16ED}' .
'\x{1735}-\x{1736}\x{17B4}-\x{17B5}\x{17D4}-\x{17D6}\x{17D8}-\x{17DB}' .
'\x{1800}-\x{180A}\x{180E}\x{1940}-\x{1945}\x{19DE}-\x{19FF}' .
'\x{1A1E}-\x{1A1F}\x{1AA0}-\x{1AA6}\x{1AA8}-\x{1AAD}\x{1B5A}-\x{1B6A}' .
'\x{1B74}-\x{1B7C}\x{1C3B}-\x{1C3F}\x{1C7E}-\x{1C7F}\x{1CD3}\x{1FBD}' .
'\x{1FBF}-\x{1FC1}\x{1FCD}-\x{1FCF}\x{1FDD}-\x{1FDF}\x{1FED}-\x{1FEF}' .
'\x{1FFD}-\x{206F}\x{207A}-\x{207E}\x{208A}-\x{208E}\x{20A0}-\x{20B8}' .
'\x{2100}-\x{2101}\x{2103}-\x{2106}\x{2108}-\x{2109}\x{2114}' .
'\x{2116}-\x{2118}\x{211E}-\x{2123}\x{2125}\x{2127}\x{2129}\x{212E}' .
'\x{213A}-\x{213B}\x{2140}-\x{2144}\x{214A}-\x{214D}\x{214F}' .
'\x{2190}-\x{244A}\x{249C}-\x{24E9}\x{2500}-\x{2775}\x{2794}-\x{2B59}' .
'\x{2CE5}-\x{2CEA}\x{2CF9}-\x{2CFC}\x{2CFE}-\x{2CFF}\x{2E00}-\x{2E2E}' .
'\x{2E30}-\x{3004}\x{3008}-\x{3020}\x{3030}\x{3036}-\x{3037}' .
'\x{303D}-\x{303F}\x{309B}-\x{309C}\x{30A0}\x{30FB}\x{3190}-\x{3191}' .
'\x{3196}-\x{319F}\x{31C0}-\x{31E3}\x{3200}-\x{321E}\x{322A}-\x{3250}' .
'\x{3260}-\x{327F}\x{328A}-\x{32B0}\x{32C0}-\x{33FF}\x{4DC0}-\x{4DFF}' .
'\x{A490}-\x{A4C6}\x{A4FE}-\x{A4FF}\x{A60D}-\x{A60F}\x{A673}\x{A67E}' .
'\x{A6F2}-\x{A716}\x{A720}-\x{A721}\x{A789}-\x{A78A}\x{A828}-\x{A82B}' .
'\x{A836}-\x{A839}\x{A874}-\x{A877}\x{A8CE}-\x{A8CF}\x{A8F8}-\x{A8FA}' .
'\x{A92E}-\x{A92F}\x{A95F}\x{A9C1}-\x{A9CD}\x{A9DE}-\x{A9DF}' .
'\x{AA5C}-\x{AA5F}\x{AA77}-\x{AA79}\x{AADE}-\x{AADF}\x{ABEB}' .
Angie Byron
committed
'\x{E000}-\x{F8FF}\x{FB29}\x{FD3E}-\x{FD3F}\x{FDFC}-\x{FDFD}' .
Dries Buytaert
committed
'\x{FE10}-\x{FE19}\x{FE30}-\x{FE6B}\x{FEFF}-\x{FF0F}\x{FF1A}-\x{FF20}' .
'\x{FF3B}-\x{FF40}\x{FF5B}-\x{FF65}\x{FFE0}-\x{FFFD}');
/**
* Wrapper around _unicode_check().
*/
function unicode_check() {
Steven Wittens
committed
list($GLOBALS['multibyte']) = _unicode_check();
Steven Wittens
committed
/**
* Perform checks about Unicode support in PHP, and set the right settings if
* needed.
*
* Because Drupal needs to be able to handle text in various encodings, we do
* not support mbstring function overloading. HTTP input/output conversion must
* be disabled for similar reasons.
*
* @param $errors
* Whether to report any fatal errors with form_set_error().
*/
Steven Wittens
committed
function _unicode_check() {
// Ensure translations don't break at install time
$t = get_t();
Steven Wittens
committed
// Check for mbstring extension
if (!function_exists('mb_strlen')) {
return array(UNICODE_SINGLEBYTE, $t('Operations on Unicode strings are emulated on a best-effort basis. Install the <a href="@url">PHP mbstring extension</a> for improved Unicode support.', array('@url' => 'http://www.php.net/mbstring')));
Steven Wittens
committed
}
// Check mbstring configuration
if (ini_get('mbstring.func_overload') != 0) {
return array(UNICODE_ERROR, $t('Multibyte string function overloading in PHP is active and must be disabled. Check the php.ini <em>mbstring.func_overload</em> setting. Please refer to the <a href="@url">PHP mbstring documentation</a> for more information.', array('@url' => 'http://www.php.net/mbstring')));
Steven Wittens
committed
}
if (ini_get('mbstring.encoding_translation') != 0) {
return array(UNICODE_ERROR, $t('Multibyte string input conversion in PHP is active and must be disabled. Check the php.ini <em>mbstring.encoding_translation</em> setting. Please refer to the <a href="@url">PHP mbstring documentation</a> for more information.', array('@url' => 'http://www.php.net/mbstring')));
Steven Wittens
committed
}
if (ini_get('mbstring.http_input') != 'pass') {
return array(UNICODE_ERROR, $t('Multibyte string input conversion in PHP is active and must be disabled. Check the php.ini <em>mbstring.http_input</em> setting. Please refer to the <a href="@url">PHP mbstring documentation</a> for more information.', array('@url' => 'http://www.php.net/mbstring')));
Steven Wittens
committed
if (ini_get('mbstring.http_output') != 'pass') {
return array(UNICODE_ERROR, $t('Multibyte string output conversion in PHP is active and must be disabled. Check the php.ini <em>mbstring.http_output</em> setting. Please refer to the <a href="@url">PHP mbstring documentation</a> for more information.', array('@url' => 'http://www.php.net/mbstring')));
Steven Wittens
committed
}
// Set appropriate configuration
mb_internal_encoding('utf-8');
mb_language('uni');
return array(UNICODE_MULTIBYTE, '');
Steven Wittens
committed
}
/**
Steven Wittens
committed
* Return Unicode library status and errors.
Steven Wittens
committed
*/
Steven Wittens
committed
function unicode_requirements() {
// Ensure translations don't break at install time
$t = get_t();
Steven Wittens
committed
$libraries = array(
UNICODE_SINGLEBYTE => $t('Standard PHP'),
UNICODE_MULTIBYTE => $t('PHP Mbstring Extension'),
UNICODE_ERROR => $t('Error'),
);
$severities = array(
UNICODE_SINGLEBYTE => REQUIREMENT_WARNING,
UNICODE_MULTIBYTE => REQUIREMENT_OK,
UNICODE_ERROR => REQUIREMENT_ERROR,
);
list($library, $description) = _unicode_check();
Steven Wittens
committed
Steven Wittens
committed
$requirements['unicode'] = array(
'title' => $t('Unicode library'),
'value' => $libraries[$library],
);
if ($description) {
$requirements['unicode']['description'] = $description;
}
$requirements['unicode']['severity'] = $severities[$library];
Steven Wittens
committed
return $requirements;
}
Gábor Hojtsy
committed
Steven Wittens
committed
/**
* Prepare a new XML parser.
*
* This is a wrapper around xml_parser_create() which extracts the encoding from
* the XML data first and sets the output encoding to UTF-8. This function should
* be used instead of xml_parser_create(), because PHP 4's XML parser doesn't
* check the input encoding itself. "Starting from PHP 5, the input encoding is
* automatically detected, so that the encoding parameter specifies only the
* output encoding."
Steven Wittens
committed
*
* This is also where unsupported encodings will be converted. Callers should
* take this into account: $data might have been changed after the call.
Steven Wittens
committed
*
Dries Buytaert
committed
* @param $data
Steven Wittens
committed
* The XML data which will be parsed later.
Steven Wittens
committed
* @return
* An XML parser object or FALSE on error.
Dries Buytaert
committed
*
* @ingroup php_wrappers
Steven Wittens
committed
*/
function drupal_xml_parser_create(&$data) {
// Default XML encoding is UTF-8
$encoding = 'utf-8';
$bom = FALSE;
Steven Wittens
committed
// Check for UTF-8 byte order mark (PHP5's XML parser doesn't handle it).
if (!strncmp($data, "\xEF\xBB\xBF", 3)) {
$bom = TRUE;
Steven Wittens
committed
$data = substr($data, 3);
}
// Check for an encoding declaration in the XML prolog if no BOM was found.
Dries Buytaert
committed
if (!$bom && preg_match('/^<\?xml[^>]+encoding="(.+?)"/', $data, $match)) {
Steven Wittens
committed
$encoding = $match[1];
}
// Unsupported encodings are converted here into UTF-8.
$php_supported = array('utf-8', 'iso-8859-1', 'us-ascii');
if (!in_array(strtolower($encoding), $php_supported)) {
$out = drupal_convert_to_utf8($data, $encoding);
if ($out !== FALSE) {
Steven Wittens
committed
$encoding = 'utf-8';
Dries Buytaert
committed
$data = preg_replace('/^(<\?xml[^>]+encoding)="(.+?)"/', '\\1="utf-8"', $out);
Steven Wittens
committed
}
else {
watchdog('php', 'Could not convert XML encoding %s to UTF-8.', array('%s' => $encoding), WATCHDOG_WARNING);
return FALSE;
Steven Wittens
committed
}
}
$xml_parser = xml_parser_create($encoding);
xml_parser_set_option($xml_parser, XML_OPTION_TARGET_ENCODING, 'utf-8');
return $xml_parser;
}
/**
* Convert data to UTF-8
*
* Requires the iconv, GNU recode or mbstring PHP extension.
*
* @param $data
* The data to be converted.
* @param $encoding
Dries Buytaert
committed
* The encoding that the data is in.
Steven Wittens
committed
* @return
* Converted data or FALSE.
*/
function drupal_convert_to_utf8($data, $encoding) {
if (function_exists('iconv')) {
$out = @iconv($encoding, 'utf-8', $data);
}
Angie Byron
committed
elseif (function_exists('mb_convert_encoding')) {
Steven Wittens
committed
$out = @mb_convert_encoding($data, 'utf-8', $encoding);
}
Angie Byron
committed
elseif (function_exists('recode_string')) {
$out = @recode_string($encoding . '..utf-8', $data);
Steven Wittens
committed
}
else {
watchdog('php', 'Unsupported encoding %s. Please install iconv, GNU recode or mbstring for PHP.', array('%s' => $encoding), WATCHDOG_ERROR);
Steven Wittens
committed
return FALSE;
}
return $out;
}
/**
* Truncate a UTF-8-encoded string safely to a number of bytes.
*
* If the end position is in the middle of a UTF-8 sequence, it scans backwards
* until the beginning of the byte sequence.
*
* Use this function whenever you want to chop off a string at an unsure
* location. On the other hand, if you're sure that you're splitting on a
* character boundary (e.g. after using strpos() or similar), you can safely use
* substr() instead.
*
* @param $string
* The string to truncate.
* @param $len
* An upper limit on the returned string length.
Gábor Hojtsy
committed
* @return
* The truncated string.
*/
function drupal_truncate_bytes($string, $len) {
if (strlen($string) <= $len) {
Gábor Hojtsy
committed
}
if ((ord($string[$len]) < 0x80) || (ord($string[$len]) >= 0xC0)) {
return substr($string, 0, $len);
}
Dries Buytaert
committed
// Scan backwards to beginning of the byte sequence.
while (--$len >= 0 && ord($string[$len]) >= 0x80 && ord($string[$len]) < 0xC0);
Gábor Hojtsy
committed
return substr($string, 0, $len);
}
/**
Dries Buytaert
committed
* Truncates a UTF-8-encoded string safely to a number of characters.
Gábor Hojtsy
committed
*
* @param $string
* The string to truncate.
Dries Buytaert
committed
* @param $max_length
* An upper limit on the returned string length, including trailing ellipsis
* if $add_ellipsis is TRUE.
Steven Wittens
committed
* @param $wordsafe
Dries Buytaert
committed
* If TRUE, attempt to truncate on a word boundary. Word boundaries are
* spaces, punctuation, and Unicode characters used as word boundaries in
* non-Latin languages; see PREG_CLASS_UNICODE_WORD_BOUNDARY for more
Angie Byron
committed
* information. If a word boundary cannot be found that would make the length
Dries Buytaert
committed
* of the returned string fall within length guidelines (see parameters
Angie Byron
committed
* $max_length and $min_wordsafe_length), word boundaries are ignored.
Dries Buytaert
committed
* @param $add_ellipsis
* If TRUE, add t('...') to the end of the truncated string (defaults to
Angie Byron
committed
* FALSE). The string length will still fall within $max_length.
Dries Buytaert
committed
* @param $min_wordsafe_length
* If $wordsafe is TRUE, the minimum acceptable length for truncation (before
* adding an ellipsis, if $add_ellipsis is TRUE). Has no effect if $wordsafe
* is FALSE. This can be used to prevent having a very short resulting string
* that will not be understandable. For instance, if you are truncating the
* string "See myverylongurlexample.com for more information" to a word-safe
* return length of 20, the only available word boundary within 20 characters
* is after the word "See", which wouldn't leave a very informative string. If
* you had set $min_wordsafe_length to 10, though, the function would realise
* that "See" alone is too short, and would then just truncate ignoring word
* boundaries, giving you "See myverylongurl..." (assuming you had set
* $add_ellipses to TRUE).
*
Steven Wittens
committed
* @return
* The truncated string.
*/
Dries Buytaert
committed
function truncate_utf8($string, $max_length, $wordsafe = FALSE, $add_ellipsis = FALSE, $min_wordsafe_length = 1) {
$ellipsis = '';
$max_length = max($max_length, 0);
$min_wordsafe_length = max($min_wordsafe_length, 0);
Gábor Hojtsy
committed
Dries Buytaert
committed
if (drupal_strlen($string) <= $max_length) {
// No truncation needed, so don't add ellipsis, just return.
Steven Wittens
committed
return $string;
}
Gábor Hojtsy
committed
Dries Buytaert
committed
if ($add_ellipsis) {
// Truncate ellipsis in case $max_length is small.
$ellipsis = drupal_substr(t('...'), 0, $max_length);
$max_length -= drupal_strlen($ellipsis);
$max_length = max($max_length, 0);
}
if ($max_length <= $min_wordsafe_length) {
// Do not attempt word-safe if lengths are bad.
$wordsafe = FALSE;
Gábor Hojtsy
committed
}
Steven Wittens
committed
if ($wordsafe) {
Dries Buytaert
committed
$matches = array();
// Find the last word boundary, if there is one within $min_wordsafe_length
// to $max_length characters. preg_match() is always greedy, so it will
// find the longest string possible.
$found = preg_match('/^(.{' . $min_wordsafe_length . ',' . $max_length . '})[' . PREG_CLASS_UNICODE_WORD_BOUNDARY . ']/u', $string, $matches);
if ($found) {
$string = $matches[1];
Gábor Hojtsy
committed
}
else {
Dries Buytaert
committed
$string = drupal_substr($string, 0, $max_length);
Steven Wittens
committed
}
Gábor Hojtsy
committed
else {
Dries Buytaert
committed
$string = drupal_substr($string, 0, $max_length);
Steven Wittens
committed
}
Gábor Hojtsy
committed
Dries Buytaert
committed
if ($add_ellipsis) {
$string .= $ellipsis;
Gábor Hojtsy
committed
}
return $string;
Steven Wittens
committed
}
/**
* Encodes MIME/HTTP header values that contain non-ASCII, UTF-8 encoded
* characters.
*
* For example, mime_header_encode('tést.txt') returns "=?UTF-8?B?dMOpc3QudHh0?=".
*
* See http://www.rfc-editor.org/rfc/rfc2047.txt for more information.
*
* Notes:
* - Only encode strings that contain non-ASCII characters.
* - We progressively cut-off a chunk with truncate_utf8(). This is to ensure
* each chunk starts and ends on a character boundary.
* - Using \n as the chunk separator may cause problems on some systems and may
* have to be changed to \r\n or \r.
*/
function mime_header_encode($string) {
if (preg_match('/[^\x20-\x7E]/', $string)) {
Steven Wittens
committed
$chunk_size = 47; // floor((75 - strlen("=?UTF-8?B??=")) * 0.75);
$len = strlen($string);
$output = '';
while ($len > 0) {
Gábor Hojtsy
committed
$chunk = drupal_truncate_bytes($string, $chunk_size);
$output .= ' =?UTF-8?B?' . base64_encode($chunk) . "?=\n";
Steven Wittens
committed
$c = strlen($chunk);
$string = substr($string, $c);
$len -= $c;
}
return trim($output);
}
return $string;
}
/**
* Complement to mime_header_encode
*/
function mime_header_decode($header) {
// First step: encoded chunks followed by other encoded chunks (need to collapse whitespace)
$header = preg_replace_callback('/=\?([^?]+)\?(Q|B)\?([^?]+|\?(?!=))\?=\s+(?==\?)/', '_mime_header_decode', $header);
// Second step: remaining chunks (do not collapse whitespace)
return preg_replace_callback('/=\?([^?]+)\?(Q|B)\?([^?]+|\?(?!=))\?=/', '_mime_header_decode', $header);
}
/**
* Helper function to mime_header_decode
*/
function _mime_header_decode($matches) {
// Regexp groups:
// 1: Character set name
// 2: Escaping method (Q or B)
// 3: Encoded data
$data = ($matches[2] == 'B') ? base64_decode($matches[3]) : str_replace('_', ' ', quoted_printable_decode($matches[3]));
if (strtolower($matches[1]) != 'utf-8') {
$data = drupal_convert_to_utf8($data, $matches[1]);
}
return $data;
}
Steven Wittens
committed
/**
* Decodes all HTML entities (including numerical ones) to regular UTF-8 bytes.
*
* Double-escaped entities will only be decoded once ("&lt;" becomes "<",
* not "<"). Be careful when using this function, as decode_entities can revert
* previous sanitization efforts (<script> will become <script>).
Steven Wittens
committed
*
* @param $text
* The text to decode entities in.
*
* @return
* The input $text, with all HTML entities decoded once.
Steven Wittens
committed
*/
Dries Buytaert
committed
function decode_entities($text) {
return html_entity_decode($text, ENT_QUOTES, 'UTF-8');
Steven Wittens
committed
}
/**
* Count the amount of characters in a UTF-8 string. This is less than or
* equal to the byte count.
Dries Buytaert
committed
*
* @ingroup php_wrappers
Steven Wittens
committed
*/
function drupal_strlen($text) {
global $multibyte;
if ($multibyte == UNICODE_MULTIBYTE) {
return mb_strlen($text);
}
else {
// Do not count UTF-8 continuation bytes.
return strlen(preg_replace("/[\x80-\xBF]/", '', $text));
}
}
/**
* Uppercase a UTF-8 string.
Dries Buytaert
committed
*
* @ingroup php_wrappers
Steven Wittens
committed
*/
function drupal_strtoupper($text) {
global $multibyte;
Steven Wittens
committed
return mb_strtoupper($text);
}
else {
// Use C-locale for ASCII-only uppercase
$text = strtoupper($text);
// Case flip Latin-1 accented letters
$text = preg_replace_callback('/\xC3[\xA0-\xB6\xB8-\xBE]/', '_unicode_caseflip', $text);
return $text;
Steven Wittens
committed
}
/**
* Lowercase a UTF-8 string.
Dries Buytaert
committed
*
* @ingroup php_wrappers
Steven Wittens
committed
*/
function drupal_strtolower($text) {
global $multibyte;
if ($multibyte == UNICODE_MULTIBYTE) {
return mb_strtolower($text);
}
else {
// Use C-locale for ASCII-only lowercase
$text = strtolower($text);
// Case flip Latin-1 accented letters
$text = preg_replace_callback('/\xC3[\x80-\x96\x98-\x9E]/', '_unicode_caseflip', $text);
return $text;
Steven Wittens
committed
}
/**
* Helper function for case conversion of Latin-1.
* Used for flipping U+C0-U+DE to U+E0-U+FD and back.
*/
function _unicode_caseflip($matches) {
return $matches[0][0] . chr(ord($matches[0][1]) ^ 32);
Steven Wittens
committed
}
/**
* Capitalize the first letter of a UTF-8 string.
Dries Buytaert
committed
*
* @ingroup php_wrappers
Steven Wittens
committed
*/
function drupal_ucfirst($text) {
// Note: no mbstring equivalent!
return drupal_strtoupper(drupal_substr($text, 0, 1)) . drupal_substr($text, 1);
}
/**
* Cut off a piece of a string based on character indices and counts. Follows
Gábor Hojtsy
committed
* the same behavior as PHP's own substr() function.
Steven Wittens
committed
*
* Note that for cutting off a string at a known character/substring
* location, the usage of PHP's normal strpos/substr is safe and
* much faster.
Dries Buytaert
committed
*
* @ingroup php_wrappers
Steven Wittens
committed
*/
function drupal_substr($text, $start, $length = NULL) {
global $multibyte;
if ($multibyte == UNICODE_MULTIBYTE) {
return $length === NULL ? mb_substr($text, $start) : mb_substr($text, $start, $length);
}
else {
$strlen = strlen($text);
// Find the starting byte offset.
Steven Wittens
committed
if ($start > 0) {
// Count all the continuation bytes from the start until we have found
// $start characters or the end of the string.
Steven Wittens
committed
$bytes = -1; $chars = -1;
while ($bytes < $strlen - 1 && $chars < $start) {
Steven Wittens
committed
$bytes++;
$c = ord($text[$bytes]);
Steven Wittens
committed
if ($c < 0x80 || $c >= 0xC0) {
$chars++;
}
}
}
Angie Byron
committed
elseif ($start < 0) {
Steven Wittens
committed
// Count all the continuation bytes from the end until we have found
// abs($start) characters.
Steven Wittens
committed
$start = abs($start);
$bytes = $strlen; $chars = 0;
while ($bytes > 0 && $chars < $start) {
$bytes--;
$c = ord($text[$bytes]);
Steven Wittens
committed
if ($c < 0x80 || $c >= 0xC0) {
$chars++;
}
}
}
$istart = $bytes;
// Find the ending byte offset.
Steven Wittens
committed
if ($length === NULL) {
$iend = $strlen;
Steven Wittens
committed
}
Angie Byron
committed
elseif ($length > 0) {
Steven Wittens
committed
// Count all the continuation bytes from the starting index until we have
// found $length characters or reached the end of the string, then
// backtrace one byte.
Dries Buytaert
committed
$iend = $istart - 1;
$chars = -1;
$last_real = FALSE;
while ($iend < $strlen - 1 && $chars < $length) {
$iend++;
$c = ord($text[$iend]);
Dries Buytaert
committed
$last_real = FALSE;
Steven Wittens
committed
if ($c < 0x80 || $c >= 0xC0) {
$chars++;
Dries Buytaert
committed
$last_real = TRUE;
Steven Wittens
committed
}
}
Dries Buytaert
committed
// Backtrace one byte if the last character we found was a real character
// and we don't need it.
if ($last_real && $chars >= $length) {
$iend--;
}
Steven Wittens
committed
}
Angie Byron
committed
elseif ($length < 0) {
Steven Wittens
committed
// Count all the continuation bytes from the end until we have found
// abs($start) characters, then backtrace one byte.
Steven Wittens
committed
$length = abs($length);
$iend = $strlen; $chars = 0;
while ($iend > 0 && $chars < $length) {
$iend--;
$c = ord($text[$iend]);
Steven Wittens
committed
if ($c < 0x80 || $c >= 0xC0) {
$chars++;
}
}
// Backtrace one byte if we are not at the beginning of the string.
if ($iend > 0) {
$iend--;
}
}
else {
// $length == 0, return an empty string.
Dries Buytaert
committed
return '';
Steven Wittens
committed
}
return substr($text, $istart, max(0, $iend - $istart + 1));