Tcl has some commands that are undocumented because they are liable to change, or even be removed, at any time, even in a patch release. Nevertheless, these commands can be very useful in exploring and understanding the inner workings of Tcl and in some cases, dealing with issues related to performance or interaction with external systems like COM on Windows.

Tcl 8.6 shipped with the Tcl Database Connectivity (TDBC) API for accessing disparate SQL database implementations in a standard manner. I happened to need it for the first time recently and collected my notes into an introductory article for the benefit of those who, like me, prefer to be spoon fed.

There is no shortage of hotkey programs for Windows, many of them of high quality. And of course Windows itself allows you to define hotkeys. However, a hotkey program in Tcl is not only very simple to write, it offers the full flexibility and power of Tcl behind it. Meaning what exactly? Read on.

There are times during software development when you want to run in interactive mode with maximum privileges on a system, be God as it were. One might think running as Administrator would do it but it doesn't. To be truly omnipotent on Windows, you have to run under the LocalSystem account^[1]. It is easy enough with Tcl and this post shows you how. As a side bonus, it also describes how to inject processes into the interactive user's desktop to run under the user's account as well.

One of the strengths of Tcl is the ease of integration with other software, whether they be COM components, libraries or even executable programs that are not designed for interaction with other programs. Here we look the facilities Tcl offers related to the last of these -- running external programs and optionally interacting with them using standard I/O mechanisms.

This post may be partially, or even completely, out of date. Both OpenSSL and the TLS extension have had major updates since it was written.

Building the Tcl TLS extension on Unix/Linux is straightforward because OpenSSL libraries are already present and installed. It's a different matter on Windows where you need to build OpenSSL yourself. This short article describes the process.

As for many pieces of software, one of the issues in testing TWAPI is the number of different platform configurations under which the test suites need to be run. Manual configuration is tedious and error-prone so automation of the process using VMware and the vix package is a big win.