What should main() return in C?

Question

AFAIK it can have something void main or int main, the question is what is recommended way and why?

Answer 1

you can do something like this from the shell -

a = ./a.out

and the program which pass the return value of the a.out or the main function which can be helpful on deciding the success or failure. So int main is the right choice.

Answer 2

Return value of main() tells how the program exited.
If the return value is zero(EXIT_SUCCESS, define in "stdlib.h") it means that the execution was successful while any non zero value will represent that something went bad in the execution.

The default return type of main() is an "int" so its recommend to avoid the use of or better don't use it.
you can use or <main()> as the default return type is int.

For example:

 int main()
 {
      printf("Here to check\n");

      return 0;    // to validate change the return value to different ..
 }

compile the program.

 ./a.out      //execute your program.
 echo $?  //execute this after executing the above it will show the exit value of "a.out"