Question

I am having some real trouble around here giving command line arguments to Visual Studio in the project options itself (in ‘Configuration Properties’ -> ‘Debugging’).

I wrote this “int main(int argc)” after the “int main(int main_i)” did not work. In the MS visual studio property pages’ Command line argument for the project I am not sure what I should write. I only want to pass a single integer to designate whether a file is to read or written to thus a mere int argc. I do not need the char *argv[]. I have tried a few values in the command line argument text box but it is not reaching the exe file when it executes, it shows what I did not enter at all.

Could you just provide me with a single simple example of what I need to enter in the MSVS C++ Property Pages’ Command Line Argument space? I simply can’t find any example on how to give the command line arguments to MSVS.

I also do not understand WHY I need to rebuild the whole project even when I just modified the command line argument value only??

Answer 1

If you want your program to understand a single integer command line argument, you still have to use argc and argv. Something like this ought to do it:

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

    if (argc < 2) {
        fprintf(stderr, "Need a command line argument.\n");
        exit(1);
    }

    int arg = atoi(argv[1]);
    // now you have an integer
    // do whatever with it...
}

The C standard requires that the main function have specific sets of parameters. One of the allowed combinations is (int, char *[]). You can name the parameters whatever you want, but they’re almost always called argc and argv.