What is the correct value to return to the operating system upon the successful completion of a program?

开发者_高级运维What is the correct value to return to the operating system upon the successful completion of a program

return EXIT_SUCCESS;

from your main() function.

Alternatively, std::exit(EXIT_SUCCESS) from just about anywhere in your program (it gets more complex if you have multiple threads/processes, obviously).

Note that on most platforms (and, in particular, POSIX), EXIT_SUCCESS has a value of 0. So return 0 or exit(0) would usually work just as well.

Your main() function should return 0 on success.

If you call exit(), you can call it with either 0 or the macro EXIT_SUCCESS. From the FDIS, 18.5.8, concerning void exit(int status):

If status is zero or EXIT_SUCCESS, an implementation-defined form of the status successful termination is returned.

To explain returning zero from main, here is 3.6.1.5:

A return statement in main has the effect of leaving the main function (destroying any objects with automatic storage duration) and calling std::exit with the return value as the argument. If control reaches the end of main without encountering a return statement, the effect is that of executing return 0;.