C语言中的main函数可以返回指针吗？

Question

As the heading goes, Is it possible for the main function return a pointer? If yes then where would be useful? Thanks!

Answer 1

Only a return type of int is blessed by the standard:

5.1.2.2.1 Program startup

1 The function called at program startup is named main. The implementation declares no prototype for this function. It shall be defined with a return type of int and with no parameters:

 int main(void) { /* ... */ } 

or with two parameters (referred to here as argc and argv, though any names may be used, as they are local to the function in which they are declared):

 int main(int argc, char *argv[]) { /* ... */ } 

or equivalent;10) or in some other implementation-defined manner.

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_{C11 draft, April 12, 2011}

Everything else is up to your compiler and therefore not a C-question anymore.

Answer 2

No. main() returns an int in standard C. The interpretation of this return value is a matter for the surrounding runtime environment. If you know exactly what you're doing, in some kind of specialized situation where you know that the environment is going to interpret the value in a certain way, then you can cast a pointer to an int. But that's nasty.

And be aware that a pointer to dynamically-allocated memory is (probably) meaningless after the program exits anyway! It would only make sense to return a pointer to a fixed address, eg a hardware register in some embedded environment.

Answer 3

完成phresnel的答案，并回答它是否有用：由于每个进程都有其自己的地址空间，即使您的main()返回一个将用作地址的整数值，自返回指针以来的关键点是什么仅与刚退出的进程的地址空间一致...