Should we use exit() in C?

Question

There is question about using exit in C++. The answer discusses that it is not good idea mainly because of RAII, e.g., if exit is called somewhere

Answer 1

Yes, it is ok to use exit in C.

To ensure all buffers and graceful orderly shutdown, it would be recommended to use this function atexit, more information on this here

An example code would be like this:

void cleanup(void){
   /* example of closing file pointer and free up memory */
   if (fp) fclose(fp);
   if (ptr) free(ptr);
}

int main(int argc, char **argv){
   /* ... */
   atexit(cleanup);
   /* ... */
   return 0;
}

Now, whenever exit is called, the function cleanup will get executed, which can house graceful shutdown, clean up of buffers, memory etc.