[fedt@yam]# time php -r 'for($i=0;$i<1000000;$i++) {$str="a\r   e \ti o u\n";$str=str_replace(array(" ","\t","\n","\r"),"",$str);strstr($str,"aeiou");}'

real    0m7.231s
user    0m7.219s
sys     0m0.016s
[fedt@yam]# time php -r 'for($i=0;$i<1000000;$i++) {$str="a\r   e \ti o u\n";preg_match("/aeiou/x",$str);}'

real    0m3.281s
user    0m3.102s
sys     0m0.148s