- function sub_str($str, $length = 0, $append = true)
- {
- $str = trim($str);
- $strlength = strlen($str);
- if ($length == 0 || $length>= $strlength)
- {
- return $str; // 截取长度等于 0 或大于等于本字符串的长度, 返回字符串本身
- }
- elseif ($length < 0) // 如果截取长度为负数
- {
- $length = $strlength + $length;// 那么截取长度就等于字符串长度减去截取长度
- if ($length < 0)
- {
- $length = $strlength;// 如果截取长度的绝对值大于字符串本身长度, 则截取长度取字符串本身的长度
- }
- }
- if (function_exists('mb_substr'))
- {
- $newstr = mb_substr($str, 0, $length, EC_CHARSET);
- }
- elseif (function_exists('iconv_substr'))
- {
- $newstr = iconv_substr($str, 0, $length, EC_CHARSET);
- }
- else
- {
- //$newstr = trim_right(substr($str, 0, $length));
- $newstr = substr($str, 0, $length);
- }
- if ($append && $str != $newstr)
- {
- $newstr .= '...';
- }
- return $newstr;
- }
来源: http://www.bubuko.com/infodetail-2970668.html