这是用了phpwind里面的一个字符串截取函数,他支持gbk,gbk2312,utf-8等多种编码的字符截取,也很好高效的支持中文字符串的处理,代码如下:

1. function substrs($content,$length,$add='Y'){
2. if (strlen($content)>$length) {
3. if ($GLOBALS['db_charset']!='utf-8') {
4. $retstr = '';
5. for ($i=0;$i<$length-2;$i++) {
6. $retstr .= ord($content[$i]) > 127 ? $content[$i].$content[++$i] : $content[$i];
7. }
8. return $retstr.($add=='Y' ? ' ..' : '');
9. }
10. return utf8_trim(substr($content,0,$length)).($add=='Y' ? ' ..' : '');
11. }
12. return $content;
13. }
14. function utf8_trim($str) {
15. $hex = '';
16. $len = strlen($str)-1;
17. for ($i=$len;$i>=0;$i-=1) {
18. $ch = ord($str[$i]);
19. $hex .= " $ch";
20. if (($ch & 128)==0 || ($ch & 192)==192) {
21. return substr($str,0,$i);
22. }
23. }
24. return $str.$hex;
25. }
26. function cutstr($string, $length, $dot = ' ...') {
27. global $charset;
28. if(strlen($string) <= $length) {
29. return $string;
30. }
31. $string = str_replace(array('&', '"', '<', '>'), array('&', '"', '<', '>'), $string);
32. $strcut = '';
33. if(strtolower($charset) == 'utf-8') {
34. $n = $tn = $noc = 0;
35. while($n < strlen($string)) {
36. $t = ord($string[$n]);
37. if($t == 9 || $t == 10 || (32 <= $t && $t <= 126)) {
38. $tn = 1; $n++; $noc++;
39. } elseif(194 <= $t && $t <= 223) {
40. $tn = 2; $n += 2; $noc += 2;
41. } elseif(224 <= $t && $t <= 239) {
42. $tn = 3; $n += 3; $noc += 2;
43. } elseif(240 <= $t && $t <= 247) {
44. $tn = 4; $n += 4; $noc += 2;
45. } elseif(248 <= $t && $t <= 251) {
46. $tn = 5; $n += 5; $noc += 2;
47. } elseif($t == 252 || $t == 253) {
48. $tn = 6; $n += 6; $noc += 2;
49. } else {
50. $n++;
51. }
52. if($noc >= $length) {
53. break;
54. }
55. }
56. if($noc > $length) {
57. $n -= $tn;
58. }
59. $strcut = substr($string, 0, $n);
60. } else {
61. for($i = 0; $i < $length; $i++) {
62. $strcut .= ord($string[$i]) > 127 ? $string[$i].$string[++$i] : $string[$i];
63. } //开源代码phpfensi.com
64. }
65. $strcut = str_replace(array('&', '"', '<', '>'), array('&', '"', '<', '>'), $strcut);
66. return $strcut.$dot;
67. }