我编写了这个php函数，它接受任何text / html字符串并修剪它。
例如：
gen_string("Hello, how are you today?",10);
返回： 你好，怎么......
当函数字符串限制与特殊字符的位置相同时会出现问题，例如：á，ñ等......
在哪种情况下：
gen_string("Helló my friend",5);
返回：地狱......
有关如何解决此问题的任何想法？这是当前的功能：
# string: advanced substr
function gen_string($string,$min,$clean=false) {
$text = trim(strip_tags($string));
if(strlen($text)>$min) {
$blank = strpos($text,' ');
if($blank) {
# limit plus last word
$extra = strpos(substr($text,$min),' ');
$max = $min+$extra;
$r = substr($text,0,$max);
if(strlen($text)>=$max && !$clean) $r=trim($r,'.').'...';
} else {
# if there are no spaces
$r = substr($text,0,$min).'...';
}
} else {
# if original length is lower than limit
$r = $text;
}
return trim($r);
}
谢谢！
答案 0 :(得分：4)
您应该使用multibyte string functions来正确处理unicode字符。
例如，您可以尝试使用mb_strimwidth将字符串截断为指定的长度。
答案 1 :(得分：1)
您也可以采用不同的方法并使用PCRE正则表达式扩展的UTF-8功能（假设您的字符串 UTF-8！）。
function gen_string($string, $length)
{
$str = trim(strip_tags($string));
$strlen = strlen(utf8_decode($str));
// String is less than limit
if ($strlen <= $length) return $str;
// Shorten string, preserving whole "words" (non-whitespace)
preg_match('/^.{'.($length-1).'}\S*/su', $str, $match);
// Append ellipsis if needed (bytes length is OK to check)
if (strlen($match[0]) !== strlen($str)) $match[0] .= '...';
return $match[0];
}
答案 2 :(得分：0)
除了多字节问题，也许你可以写得更短
function gen_string($str, $limit) {
if ($str >= strlen($limit))
return $str;
$offset = -(strlen($str) - $limit);
return substr($str, 0, strrpos($str, ' ', $offset)).'...';
}
它会限制字符串的长度，所以不要在超出限制的第一个字之后剪切它，而是确保长度永远不会超过限制。
答案 3 :(得分：0)
strlen()不能用于UTF-8字符串，因为它也会计算连续字符，不应计算。
您可以尝试使用以下代码：
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}' .
'\x{D800}-\x{F8FF}\x{FB29}\x{FD3E}-\x{FD3F}\x{FDFC}-\x{FDFD}' .
'\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}');
function utf8_strlen($text) {
if (function_exists('mb_strlen')) {
return mb_strlen($text);
}
// Do not count UTF-8 continuation bytes.
return strlen(preg_replace("/[\x80-\xBF]/", '', $text));
}
function utf8_truncate($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);
if (utf8_strlen($string) <= $max_length) {
// No truncation needed, so don't add ellipsis, just return.
return $string;
}
if ($add_ellipsis) {
// Truncate ellipsis in case $max_length is small.
$ellipsis = utf8_substr('...', 0, $max_length);
$max_length -= utf8_strlen($ellipsis);
$max_length = max($max_length, 0);
}
if ($max_length <= $min_wordsafe_length) {
// Do not attempt word-safe if lengths are bad.
$wordsafe = FALSE;
}
if ($wordsafe) {
$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];
}
else {
$string = utf8_substr($string, 0, $max_length);
}
}
else {
$string = utf8_substr($string, 0, $max_length);
}
if ($add_ellipsis) {
$string .= $ellipsis;
}
return $string;
}
function utf8_substr($text, $start, $length = NULL) {
if (function_exists('mb_substr')) {
return $length === NULL ? mb_substr($text, $start) : mb_substr($text, $start, $length);
}
else {
$strlen = strlen($text);
// Find the starting byte offset.
$bytes = 0;
if ($start > 0) {
// Count all the continuation bytes from the start until we have found
// $start characters or the end of the string.
$bytes = -1;
$chars = -1;
while ($bytes < $strlen - 1 && $chars < $start) {
$bytes++;
$c = ord($text[$bytes]);
if ($c < 0x80 || $c >= 0xC0) {
$chars++;
}
}
}
elseif ($start < 0) {
// Count all the continuation bytes from the end until we have found
// abs($start) characters.
$start = abs($start);
$bytes = $strlen;
$chars = 0;
while ($bytes > 0 && $chars < $start) {
$bytes--;
$c = ord($text[$bytes]);
if ($c < 0x80 || $c >= 0xC0) {
$chars++;
}
}
}
$istart = $bytes;
// Find the ending byte offset.
if ($length === NULL) {
$iend = $strlen;
}
elseif ($length > 0) {
// 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.
$iend = $istart - 1;
$chars = -1;
$last_real = FALSE;
while ($iend < $strlen - 1 && $chars < $length) {
$iend++;
$c = ord($text[$iend]);
$last_real = FALSE;
if ($c < 0x80 || $c >= 0xC0) {
$chars++;
$last_real = TRUE;
}
}
// Backtrace one byte if the last character we found was a real character
// and we don't need it.
if ($last_real && $chars >= $length) {
$iend--;
}
}
elseif ($length < 0) {
// Count all the continuation bytes from the end until we have found
// abs($start) characters, then backtrace one byte.
$length = abs($length);
$iend = $strlen;
$chars = 0;
while ($iend > 0 && $chars < $length) {
$iend--;
$c = ord($text[$iend]);
if ($c < 0x80 || $c >= 0xC0) {
$chars++;
}
}
// Backtrace one byte if we are not at the beginning of the string.
if ($iend > 0) {
$iend--;
}
}
else {
// $length == 0, return an empty string.
return '';
}
return substr($text, $istart, max(0, $iend - $istart + 1));
}
}
答案 4 :(得分：-1)
您的退货声明可以尝试：
return htmlspecialchars(trim($r));
编辑：我按照你提供的方式尝试了你的代码，并且在没有使用htmlspecialchars()的情况下运行正常。这可能是由于在代码运行的页面的<head>中，charset被设置为UTF-8。所以你的选择可能是设置页面的编码，如下所示：
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
或如上所述使用htmlspecialchars()。