Printing Variables And Expressions

• Without being able to examine variables contents during program execution, the whole idea of using a debugger is quite lost. You can print the contents of a variable with a command like this:
  (gdb) print i
  And then you'll get a message like:
  $1 = 0
  which means that "i" contains the number "0".
• Note that this requires "i" to be in scope, or you'll get a message such as:
  No symbol "i" in current context.
• For example, if you break inside the "print_string" function and try to print the value of "i", you'll get this message. You may also try to print more complex expressions, like "i*2", or "argv[3]", or "argv[argc]", and so on.
• In fact, you may also use type casts, call functions found in the program. Again, this is a good time to try this out.