This is for a cron job or other command line use? If you don't require a particular version of PHP (the default is fine), just php will work. If your server supports multiple versions of PHP (there's no guarantee that the one used by a web page will be the same one that is the command line default), you'll have to search for different php binaries:
find / -name php -print 2>/dev/nulland figure out which one is the version you require. You might have to open a support ticket to ask which is which.