C main() function

What does int main(int argc, char *argv[]) mean?

argv and argc are how command-line arguments are passed to main.

• argc (argument count)

  • The number of argument strings pointed to by argv
  • Should just be $1+\text{number of arguments}$

• argv (argument vector)

  • List of arguments

These are only called argc and argv by convention, could just as well be int main(int num_of_args, char **arg_strings) or something.

int main() with no arguments can be used if you don’t intend to pass process command line arguments.

Example:

#include <iostream>
 
int main(int argc, char** argv) {
    std::cout << "Have " << argc << " arguments:" << std::endl;
    for (int i = 0; i < argc; ++i) {
        std::cout << argv[i] << std::endl;
    }
}

prompt> ./test a1 b2 c3
Have 4 arguments
./test
a1
b2
c3