# Extra Clang Tools 4 documentation

## clang-tidy - cert-env33-c

# cert-env33-c

This check flags calls to `system()`, `popen()`, and `_popen()`, which execute a command processor. It does not flag calls to `system()` with a null pointer argument, as such a call checks for the presence of a command processor but does not actually attempt to execute a command.

This check corresponds to the CERT C Coding Standard rule ENV33-C. Do not call system().