Question

How to run a c++ code say (test.cpp) from command line as:

./solve l m

where l and m = input variable for test.cpp

solve is the object / Executable file for test.cpp.

I know that i can create a object file with

g++ test.cpp -o solve

but how do i make

./solve l m

work ??

Answer 1

Main() takes two inputs. The first (argc) is the number of inputs (in your case 2, l and m), and it puts the two into a char* array (argv[]). So in main you’d do:

#include <iostream> 
using namespace std;

int main(int argc, char* argv[]) { 
   cout << "argc = " << argc << endl; 
   for(int i = 0; i < argc; i++) 
      cout << "argv[" << i << "] = " << argv[i] << endl; 
   return 0; 
}

Read parsing command line args here:http://www.site.uottawa.ca/~lucia/courses/2131-05/labs/Lab3/CommandLineArguments.html