Can I omit return from main in C?

Question

In C++, 3.6.1 Main function

(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 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;

Can I do the following in C99 without return 0?

int main() { }

@NPE: C99 Standard is freely avalaible online. And possible duplicate that also answers the question: http://stackoverflow.com/q/204476/1202636 — effeffe, Nov 24 '12 at 20:33
@NPE: the released standard costs money in both cases (at least for a legitimate copy). In either case, drafts almost indistinguishable from the real standard are available for free. — Jerry Coffin, Nov 24 '12 at 20:41
@NPE: actually I can easily find free PDFs of all major revisions of C and C++ standard except for C89 (just found a plain ASCII draft...), sometimes they are draft, but they are the same as the real standard. — effeffe, Nov 24 '12 at 20:43

score 16 · Accepted Answer · edited Nov 24 '12 at 20:36

Yes, as of C99, reaching the } at the end of main returns 0 if the return type of main is compatible with int.

5.1.2.2.3 Program termination

If the return type of the main function is a type compatible with int, a return from the initial call to the main function is equivalent to calling the exit function with the value returned by the main function as its argument;¹¹⁾ reaching the } that terminates the main function returns a value of 0. If the return type is not compatible with int, the termination status returned to the host environment is unspecified.

score 9 · Answer 2 · answered Nov 24 '12 at 20:32

9

Yes, the C99 standard says (§5.1.2.2.3):

reaching the } that terminates the main function returns a value of 0.

answered Nov 24 '12 at 20:32

Joseph Mansfield

108,238
20
242
324

Can I omit return from main in C?

2 Answers2

Linked

Related