mb_ereg_search

mb_ereg_search & subpatterns
use loop:
<?php
 $str = "中国abc + abc ?!?!字符# china string";
 $reg = "\w+";
 mb_regex_encoding("UTF-8");
 mb_ereg_search_init($str, $reg);
 $r = mb_ereg_search();
 if(!$r)
 {
 echo "null\n";
 }
 else
 {
 $r = mb_ereg_search_getregs(); //get first result
 do
 {
 var_dump($r[0]);
 $r = mb_ereg_search_regs();//get next result
 }
 while($r);
 }
?>

A 'match_all' helper function based on dulao's answer. Someone might find it useful...
<?php
function mb_ereg_match_all($pattern, $subject, &$matches, $options = '', $setOrder = false, $offset = 0) {
 if (!mb_ereg_search_init($subject, $pattern, $options)) {
 return false;
 }
 if ($offset != 0 && !mb_ereg_search_setpos($offset)) {
 return false;
 }
 $matches = [];
 if (!mb_ereg_search()) {
 return 0;
 }
 $regs = mb_ereg_search_getregs();
 $count = 0;
 do {
 $count++;
 if ($setOrder) {
 foreach ($regs as $key => $val) {
 $matches[$key][] = $val;
 }
 } else {
 $matches[] = $regs;
 }
 $regs = mb_ereg_search_regs();
 }
 while($regs);
 return $count;
}
?>