Question

I know when the address of the function is passed to atexit function,
the function is excuted.

#include <stdlib.h>
int atexit(void (*func) void));

However, what is the purpose of using atexit function?

Does verbal meaning itself ‘exit’ relate to atexit function?

Answer 1

atexit would be used for some code that you want to execute when the application terminates, regardless of where it was exited from. One example would be an application-wide logger. You would call atexit(flush_log), so when the application exits, the log will be flushed, without the developer having to remember to flush it.