Main bazar fatafat: _tmain does not exist

_tmain does not exist in C++. main does. _tmain is a Microsoft extension. main is, according to the C++ standard, the program's entry point. It has one of these two signatures: int main (); int main (int argc, char" argv[]); Microsoft has added a wmain which replaces the second signature with this: int wmain(int argc, wchar_t" argv[]); And then, to make it easier to switch between Unicode (UTF-16) and their multibyte character set, they've defined _tmain which, if Unicode is enabled, is ... If you are trying to close a question where someone should be using this idiom and isn't, consider closing as a duplicate of Why is Python running my module when I import it, and how do I stop it? instead. For questions where someone simply hasn't called any functions, or incorrectly expects a function named main to be used as an entry point automatically, use Why doesn't the main () function run when I start a Python script? Where does the script start running?. What is the correct (most efficient) way to define the main () function in C and C++ — int main () or void main () — and why? And how about the arguments? If int main () then return 1 or return 0? If you want examples of main () calling main (), here are plenty: ioccc.org It's the website of the International Obfuscated C Code Contest, and folding everything into a single function called main is an effective obfuscation technique.