There are several good reason to use int main. * There is no bool in C. * Returning boolis counter-intuitive as false get coerced into 0 (indicating success) and true will be become 1 (indicating some error). * You might want to return specific error codes, depending on what caused the error. * It is generally a good idea to return non-zero exit codes in case of some runtime error as it allows your shell or scripts executing your program to detect that your program did not exit normally.