Is it possible to pass input arguments to an executable in the command line

Question

let's say I have this c++ code which I compiled into an executable out.exe

int main(){   
   int a = 0;  
   cin>>a;

   if (a)    
      cout<<"done";  

   return 0;  
}

Normally I would execute it using the command line by typing its name, then it would wait for my input.

However, what I want it to pass the input in the same line that I am calling the executable like so:

out.exe 1

1 being the input so the program wouldn't wait for my input and directly outputs:

done

What you're looking for is called "input stream redirection" or "input stream piping". I'm not sure how it works under windows, should be something like echo 1 | out.exe — Denis Sheremet
– Denis Sheremet, Commented Jan 17, 2020 at 11:51
There's also an option to use command-line arguments instead. If you'll update main signature to int main(int argc, char** argv), argv will be a c-string array containing all arguments you've provided after out.exe, and argc would be their count — Denis Sheremet
– Denis Sheremet, Commented Jan 17, 2020 at 11:53

anastaciu · Accepted Answer · 2020-01-17 12:03:31Z

4

You can use int main(int argc, char **argv) command line arguments **argv, and argument counter argc look in What does int argc, char *argv[] mean?.

The arguments are read as strings but you can easily convert them into the type you need, in this case int. How can I convert a std::string to int?

answered Jan 17, 2020 at 11:53

anastaciu

24.1k7 gold badges37 silver badges62 bronze badges

Sign up to request clarification or add additional context in comments.

1 Answer 1