tcsim terminates in one of the following three ways:
The latter case deserves special attention because tcsim reads and processes commands as it proceeds with the simulation. It may therefore detect an error in a configuration only after possibly having spent a long while processing earlier parts of the simulation. Long-running simulations should therefore be checked for syntax errors with the -c option first.
All commands but every can follow end, although the use of time is discouraged. Typically, only tc commands are useful after end.
If a simulation does not use end, it simply stops when reaching the end of the script, without waiting for timers.