Topic on intercepting strings in PHP

1. Intercept the gb2312 Chinese string <? Php <? PHP // extract the Chinese string function mysubstr ($ STR, $ start, $ Len) {$ tmpstr = ""; $ strlen = $ start + $ Len; for ($ I = 0; $ I <$ strlen; $ I ++) {If (ord (substr ($ STR, $ I, 1)> 0xa0) {$ tmpstr. = substr ($ STR, $ I, 2); $ I ++;} else $ tmpstr. = substr ($ STR, $ I, 1);} return $ tmpstr ;}?> 2. truncate a UTF-8 encoded multi-byte string <? Php <? PHP // intercept the utf8 string function utf8substr ($ STR, $ from, $ Len) {return preg_replace ('# ^ (?: [\ X00-\ x7f] | [\ xc0-\ xFF] [\ X80-\ xbf] +) {0 ,'. $ from. '}'. '((?: [\ X00-\ x7f] | [\ xc0-\ xFF] [\ X80-\ xbf] +) {0 ,'. $ Len. '}). * # s', '$ 1', $ Str) ;}?> 3. Chinese Character truncation functions supported by UTF-8 and gb2312 <? Php <? PHP/* Utf-8, gb2312 are supported by the Chinese character truncation function cut_str (string, truncation length, start length, encoding ); the default encoding start length is UTF-8. The default value is 0 */function cut_str ($ string, $ sublen, $ start = 0, $ code = 'utf-8 ') {if ($ code = 'utf-8 ') {$ Pa = "/[\ x01-\ x7f] | [\ xc2-\ xdf] [\ X80-\ xbf] | \ xe0 [\ xa0-\ xbf] [\ x80-\ xbf] | [\ xe1-\ XeF] [\ X80-\ xbf] [\ X80-\ xbf] | \ xf0 [\ x90-\ xbf] [\ X80 -\ xbf] [\ X80-\ xbf] | [\ xf1-\ xf7] [\ X80-\ xbf] [\ X80-\ xbf] [\ X80-\ xbf] /"; preg_match_all ($ Pa, $ string, $ t_string ); If (count ($ t_string [0])-$ Start> $ sublen) return join ('', array_slice ($ t_string [0], $ start, $ sublen )). "... "; return join ('', array_slice ($ t_string [0], $ start, $ sublen);} else {$ start = $ start * 2; $ sublen = $ sublen * 2; $ strlen = strlen ($ string); $ tmpstr = ''; For ($ I = 0; $ I <$ strlen; $ I ++) {if ($ I >=$ start & $ I <($ start + $ sublen) {If (ord (substr ($ string, $ I, 1)> 129) {$ tmpstr. = substr ($ string, $ I, 2);} else {$ tmpstr. = substr ($ string, $ I, 1) ;}if (ord (substr ($ string, $ I, 1)> 129) $ I ++ ;} if (strlen ($ tmpstr) <$ strlen) $ tmpstr. = "... "; return $ tmpstr ;}}$ STR =" string to be intercepted by ABCD "; echo cut_str ($ STR, 8, 0, 'gb2312');?> 4. bugfree character truncation function <? Php <? PHP/*** @ package bugfree * @ version $ ID: functionsmain. inc. PHP, V 1.32 11:38:37 wwccss exp $ *** return part of a string (enhance the function substr ()) ** @ author Chunsheng Wang <wwccss@263.net> * @ Param string $ string the string to cut. * @ Param int $ length the length of returned string. * @ Param booble $ append whether APPEND "... ": false | true * @ return string the cutted string. */ Function syssubstr ($ string, $ length, $ append = false) {If (strlen ($ string) <= $ length) {return $ string;} else {$ I = 0; while ($ I <$ length) {$ stringtmp = substr ($ string, $ I, 1); If (ord ($ stringtmp)> = 224) {$ stringtmp = substr ($ string, $ I, 3); $ I = $ I + 3;} elseif (ord ($ stringtmp) >= 192) {$ stringtmp = substr ($ string, $ I, 2); $ I = $ I + 2;} else {$ I = $ I + 1 ;} $ stringlast [] = $ stringtmp;} $ s Tringlast = implode ("", $ stringlast); if ($ append) {$ stringlast. = "... ";}return $ stringlast ;}$ string =" codebit.cn -- simple, brilliant, General "; $ length =" 18 "; $ append = false; echo syssubstr ($ string, $ length, $ append);?>