Don’t get me wrong, regex is awesome, and entirely useful—sometimes it’s the only option, it’s just not the best tool of choice for wire speed applications.  Often the sys-admin and network type converts to BIG-IP will find the regexp tcl command and go that route because it’s familiar.  If that describes you, please let me introduce you to a couple more appropriate commands:

These two commands will cover a great percentage of regexp’s use cases, and will save significant resources on the system.  Don’t buy it?  Here’s an example: