19 Reentrant C Scanners

flex has the ability to generate a reentrant C scanner. This is accomplished by specifying %option reentrant (‘-R’) The generated scanner is both portable, and safe to use in one or more separate threads of control. The most common use for reentrant scanners is from within multi-threaded applications. Any thread may create and execute a reentrant flex scanner without the need for synchronization with other threads.