Step into Xcode Mac OS X Development

Chapter 3. Simple Active Debugging

The Next Step

In Chapter 2, we got the Linrg command line tool to build without errors and used the Xcode debugger passively to track down and eliminate an early crashing bug. Let’s run our tool again and see how it goes. Make sure that the project is built, and select Debug Executable from the Build and Go menu in the Project window’s toolbar.

Once again, we select Standard I/O Log from the Debug menu, so we can interact with Linrg. Type some data:

   1.0  2.05
   nan nan nan

Well, after we enter two numbers and press Return, Linrg does not crash. It simply prints nan nan nan and quits. The status bar in the Debugger and Project windows says, “Debugging of Executable ‘Linrg’ ended normally.”

Something else is wrong. An ...