This is more of a php question than a WP question, but there’s a great function here that does what you’re looking for.
function is_mobile() {
// Get the user agent
$user_agent = $_SERVER['HTTP_USER_AGENT'];
// Create an array of known mobile user agents
// This list is from the 21 October 2010 WURFL File.
// Most mobile devices send a pretty standard string that can be covered by
// one of these. I believe I have found all the agents (as of the date above)
// that do not and have included them below. If you use this function, you
// should periodically check your list against the WURFL file, available at:
// http://wurfl.sourceforge.net/
$mobile_agents = Array(
// List of mobile agents
);
// Pre-set $is_mobile to false.
$is_mobile = false;
// Cycle through the list in $mobile_agents to see if any of them
// appear in $user_agent.
foreach ($mobile_agents as $device) {
// Check each element in $mobile_agents to see if it appears in
// $user_agent. If it does, set $is_mobile to true.
if (stristr($user_agent, $device)) {
$is_mobile = true;
// break out of the foreach, we don't need to test
// any more once we get a true value.
break;
}
}
return $is_mobile;
}
You can then call the function to wrap whatever you want like this:
if (is_mobile()) {
// Place code you wish to execute if browser is mobile here
}
else {
// Place code you wish to execute if browser is NOT mobile here
}