Microsoft has published a new Command Line Standard which sets out the standard for writing command line applications for Microsoft platforms … While it’s clearly based on the way they’ve written PowerShell, it is a spec that is “independent of any specific implementation of a shell, set of utilities or command creation technologies” and should be used for any command line interface apps for DOS, too (especially since doing so would enable your app to function in a PowerShell pipeline as well).
Anyway, it looks really interesting, and I can’t help but think that perhaps the Linux command-line could benefit from apps implementing this standard too . In particular, I like the TCSV format option as a way of enhancing plain old CSV data with type and structure information … and the standardized naming convention. Ultimately, these five points (from the spec) should be the standard for any command-line interface (although I know many linux die-hards will note they’ve been living without number five for many years):
- Consistent verb and parameter naming conventions.
- Consistent command syntax
- Common behaviors.
- Consistent error messages and exit codes.
- Schema-enhanced data streams and formatting.
However, Appendix A – Standardized Verb Sets and Verb Names got my attention in particular, because it actually obsoletes a few of the Verbs that were in this list on the PowerShell blog and which they’ve actually been using in the Community Extensions … Specifically, Write is marked as obsolete in favor of Set — and it’s pair Get, is to be used instead of the obsolete Read. In addition, there’s no mention of Out and *Where* is only mentioned as an obsolete version of Resolve (which really made me wonder about “Where-Object” but I guess that can be the exception that proves the rule?). The spec actually says that it is required to use verbs from the list of standard verbs in Appendix A., so there doesn’t seem to be an option to invent your own verbs.
If you have any comments about the spec, I guess you should put them on this post on their blog, rather than on this thread in the PSCX forum.
I’ll have to write another post on this later, after I’ve had a chance to re-read the spec and digest it a bit … so far it looks really good, but it sure would throw the monkey-wrench in my old console “Hello World” apps in C++ and Java … I wonder if someone will create a wrapper to make writing compliant command line apps easier (without resorting to writing PowerShell commandlets which are practically compliant automatically). I also wonder how long it will be until a new PowerShell release comes out that actually understands TCSV...