Tip: Don't rely on environment variables for critical decisions

billwert — Mon, 25 Feb 2008 05:35:49 GMT

I saw a mail this week asking how you can determine what bitness your process is running in, and one of the suggestions was to check for the PROCESSOR_ARCHITEW6432 environment variable. If that variable exists, you know you're on 64 bit Windows in a 32 bit process. It's likely that the questioner needs to know which bitness the application is running in so the correct bitness DLL can be loaded, since by default native code is processor agnostic.

This is one example, but the broader point really is that you shouldn't rely on environment variables as proof of things important to your application. It is too easy for someone to intentionally or accidentally corrupt your environment and cause your program to function incorrectly. Please don't do this in shipping code.

The best laid plans...

billwert — Wed, 07 Apr 2004 19:10:00 GMT

I started this, as most do, with the best of intentions. A long list of topics to discuss, potentially interesting things to say, and so forth. Then, as is usual, life interrupted.

So, I put forth the question to the proverbial teeming masses of the readership: What do you want to know about testing performance? Some thoughts:

Workingset measurement
Scalability measurment
Startup time
?

Let me know what you're dying to know.

Bill Wert's weblog : General Stuff

Tip: Don't rely on environment variables for critical decisions

The best laid plans...