<?php
header('Content-type: text/plain; charset=utf-8');
function printTruncated($maxLength, $html, $isUtf8=true) {
$printedLength = 0;
$position = 0;
$tags = array();
// For UTF-8, we need to count multibyte sequences as one character.
$re = $isUtf8
? '{</?([a-z]+)[^>]*>|&#?[a-zA-Z0-9]+;|[\x80-\xFF][\x80-\xBF]*}'
: '{</?([a-z]+)[^>]*>|&#?[a-zA-Z0-9]+;}';
while ($printedLength < $maxLength && preg_match($re, $html, $match, PREG_OFFSET_CAPTURE, $position)) {
list($tag, $tagPosition) = $match[0];
// Print text leading up to the tag.
$str = substr($html, $position, $tagPosition - $position);
if ($printedLength + strlen($str) > $maxLength) {
print(substr($str, 0, $maxLength - $printedLength));
$printedLength = $maxLength;
break;
}
print($str);
$printedLength += strlen($str);
if ($printedLength >= $maxLength) break;
if ($tag[0] == '&' || ord($tag) >= 0x80) {
// Pass the entity or UTF-8 multibyte sequence through unchanged.
print($tag);
$printedLength++;
} else {
// Handle the tag.
$tagName = $match[1][0];
if ($tag[1] == '/') {
// This is a closing tag.
$openingTag = array_pop($tags);
assert($openingTag == $tagName); // check that tags are properly nested.
print($tag);
} else
if ($tag[strlen($tag) - 2] == '/') {
// Self-closing tag.
print($tag);
} else {
// Opening tag.
print($tag);
$tags[] = $tagName;
}
}
// Continue after the tag.
$position = $tagPosition + strlen($tag);
}
// Print any remaining text.
if ($printedLength < $maxLength && $position < strlen($html)) {
print(substr($html, $position, $maxLength - $printedLength));
}
// Close any open tags.
while (!empty($tags)) {
printf('</%s>', array_pop($tags));
}
}
printTruncated(30, 'текст текст <span>текст текст текст </span>'); print("\n");
printTruncated(30, 'текст текст <a> текст текст текст текст
текст</a>'); print("\n");
printTruncated(30, "текст текст текст текст"); print("\n");