Help with learning how to compile small project (3 files)

[jmvbxx]

I am a brand new coder learning from C++ for Mathematicians. I have three files: gcd.h, gcd.cpp and gcd-tester.cpp

What I'd like to know if how to compile them so that I can run them.

I believe that gcd-tester.cpp needs gcp.cpp in order to compile.

Here is the error I receive:

~/coding/cpp/gcd$ g++ gcd-tester.cc -o gcd-tester
/tmp/ccvi6bre.o: In function `main':
gcd-tester.cc.text+0xcc): undefined reference to `gcd(long, long)'
collect2: ld returned 1 exit status

Any help is very appreciated!

Here is the code for gcd-tester.cpp

   #include "gcd.h"
   #include <iostream>
   using namespace std;

   /**
     * A program to test the gcd procedure.
     */

   int main() {

      long a,b;

      cout << "Enter the first number --> ";
      cin >> a;
      cout << "Enter the second number --> ";
      cin >> b;

      cout << "The gcd of " << a << " and " << b << " is "
           << gcd(a,b) << endl;
      return 0;
   }

 

[chipperMDW]

For a simple project, you can get away with listing both source files on the command line:

$ g++ gcd.cpp gcd-tester.cpp -o gcd-tester

However, the correct way (especially on larger projects) is to compile each source file into an object file (ending with[tt] .o[/tt]) using the[tt] -c [/tt]option, then link the object files together:

$ g++ -c gcd.cpp
$ g++ -c gcd-tester.cpp
$ g++ gcd.o gcd-tester.o -o gcd-tester

You may also want to look into creating a Makefile do perform these steps for you.

 

[jmvbxx]

Works! Thank you so much!