GFact | How to define main function in ISO C?

In ISO C, you can define main either to take no arguments, or to take two arguments that represent the command line arguments to the program, like this:

int main (int argc, char *argv[])

Other platform-dependent formats are also allowed by the C and C++ standards; for example, Unix (though not POSIX.1) and Microsoft Visual C++ have a third argument giving the program’s environment, otherwise accessible through getenv in stdlib.h: