void copyoutstr(string str, uintptr_t addr, size_t maxlen)

The copyoutstr action copies the string tha tis specified by str to the address that is specified by addr in the address space of the process associated with the current thread. If the user-space address does not correspond to a valid, faulted-in page in the current address space, an error is generated. Note that the string length is limited to the value that is set by the strsize option. See Chapter 10, Options and Tunables.