iRule to persist on tcp_content

Check the doc Using UIE Function Commands under Tech Tips. Gives the syntax for the findstr command. An excerpt:

 

 

findstr

 

The findstr command finds the string within and returns a sub-string based on the and from the matched location.

 

 

Note the following;

 

 

may be either a character or length.

 

If is not specified, it defaults to zero.

 

If is not specified, it defaults to the end of the string.

 

This command (without or is equivalent to the following Tcl command: "string range [string first ] end".

 

The syntax of the findstr() command is as follows:

 

 

findstr [ []

 

 

 

Also, the ne is "not equal", so if the string is usrid has has content, persist on it.