Debugging

While logging techniques save information about execution flow to allow you to analyze it later, debugging offers a different concept. It allows you to interact with a live, running application, review and modify its internal state, and halt execution at points of your choice using breakpoints.

The best graphical debugging tools, Inspector and Debugger, are offered by ActiveState as a part of the Tcl Dev Kit bundle, available at http://www.activestate.com/tcl_dev_kit/. There is a 21-day free trial period, so you do not need to buy it blindly. In this chapter, we will describe the tools offered by version 5.1.0. We will also describe its ancestor, the free TclPro Debugger (version 1.4), available at http://www.tcl.tk/software/tclpro/. Although it is based on old Tcl 8.3, it is still a free alternative worth considering.

Tcl Dev Kit Inspector

Before we focus on debuggers, we will first discuss the Tcl Dev Kit Inspector, which is not really a thorough-bred debugging application. It...