正则表达式在第一场比赛时停止，我不希望它

This is happening in multiple places, but here is an example. I am trying to grab name servers from /etc/resolv.conf

nameserver 1.1.1.1
nameserver 2.2.2.2

Here is my regex, it works for only the first match. Why can I not match ALL nameservers here? My $match array only has ne value.

preg_match('/nameserver ([^\s]+)/', $fileContents, $match);

Thanks for reading.