I am not too good at these things, so bear with me. I’ve been seeing more and more configs (both in terms of answering questions on these forums, and via IRC, with ad-hoc email, etc.) that seem to be redefining existing functionality for no good reason other than (I assume) ignorance.
So here’s a few things to bear in mind (in no particular order):
Ah yes. SetEnv. I would never had imagined how such an insignificant command would annoy me so much, especially through its apparent mis-use. It seems more and more people are defining things like this:
SetEnv fvwm_home $[HOME]/.fvwm
Which is innocent enough, and indeed works. Except for the fact that it’s completely unnecessary. FVWM defines for you (which you yourself can change) the environment variable FVWM_USERDIR which by default will point to ~/.fvwm – so why in hell people seem to think setting “fvwm_home” is doing themselves any good is beyond me.
Now consider for the moment the implications of doing so. By and large it’s fine, because you presumably wrote the configuration, right? Well, yes, but what happens when you decide to share your all singing all dancing, brand-new complex function you spent the past two days trying to write? What if it contains a reference to “fvwm_home”? The person deciding to try that function is going to come unstuck because he or she may not have “fvwm_home” defined. You should always rely on using “FVWM_USERDIR” where you need to reference a likely and pre-defined location for personal configuration files.
If you’re one of these people whom uses a split configuration file via a series of Read commands, and hence had relied on something like:
Read understands (and expands) the variable “$.” relative to a path – so you can use that as well to further increase neutrality.
Not to mention that it leaves endless environment variables defined which might only ever get used once.
- InitFunction versus StartFunction versus RestartFunction
Unless you’re someone as foolish as I am, and are still using FVWM 2.4.19, FVWM 1.24 and FVWM 2.2.5, this is going to be of consideration to you. OK, I joke. This is really only of importance to the small minority of people running FVWM stable (2.4.19). For the rest of you running 2.5.X (at the time I writing I would hope 2.5.16) then you need to be made aware of the following:
You don’t need to use InitFunction
Gasp! It’s true. In FVWM 2.4.X, you do need to use it because the Test command does not include tests for Init, Reboot, etc. However for FVWM 2.5.X, forget InitFunction, and incorporate it into your StartFunction. Here’s an example:
DestroyFunc InitFunction AddToFunc InitFunction + I Exec exec xsetroot -solid pink + I Exec exec xconsole DestroyFunc StartFunction AddToFunc StartFunction + I Module FvwmProxy + I Module FvwmButtons myBar
Put the two together, and from within your StartFunction you can define what’s in InitFunction via the use of the following:
+ I Test (Init) ...
DestroyFunc StartFunction AddToFunc StartFunction + I Module FvwmProxy + I Module FvwmButtons myBar + I Test (Init) Exec exec xsetroot -solid pink + I Test (Init) Exec exec xconsole
And that’s it. There you have it. You now have a StartFuction which FVWM reads at Init, Reboot and Exit. The same logic applies for RestartFunction:
You don’t need to use RestartFunction
What is even more perplexing about this is I have seen a lot of configs which define the following:
DestroyFunc StartFunction AddToFunc StartFunction + I Exec exec xterm -T Wooo -ls DestroyFunc RestartFunction AddToFunc RestartFunction + I Exec exec xterm -T Woo -ls
Now, guess what this does. That’s right, when you reboot FVWM you get two copies of the same xterm running. That’s because, again, StartFunction is read by FVWM at initialisation and reboots. FVWM hence re-reads RestartFunction and StartFunction and does the same thing twice. How do you get around this. Easy: remove the definition for RestartFunction entirely. If that application is only intended to be started during a restart (slightly odd scenario) then use:
DestroyFunc StartFunction AddToFunc StartFunction + I Test (Restart) Exec exec xterm -T Woo -ls
- Exec exec and the dreaded FvwmCommand versus PipeRead.
This one baffles me profoundly. The classic observation of this is with some of the many different incantations of Thumbnail functions that exist. Here’s a snippet:
DestroyFunc Thumbnail AddToFunc Thumbnail + I Exec nice 19...; some_other_shell_commands; FvwmCommand 'WindowStyle foo, bar'
ARGH! What the hell is that all about? For the love of God, learn how to use PipeRead. Please? It’s not that hard. Consider what’s happening with the above. Exec forces a shell, some idiotic processing goes on (probably running convert a few times) and then FvwmCommand forces FVWM to be told instructions via FIFO. How dull, when all this time PipeRead would have saved you all of the superluousness of it all.
PipeRead forces a shell, but more importantly one is then able to “echo” commands back to FVWM. Not only does this synchronise things (especially if the PipeRead command exists within a function) but it means you don’t have to worry about sending commands back indirectly via FvwmCommand. FvwmCommand is only useful if you’re calling some external script that doesn’t rely on directly ending with FVWM (or where you don’t want it to block with PipeRead).
If you ever find yourself writing:
+ I Exec ...; FvwmCommand '....'
You want PipeRead.
- I’m too good to use ImagePath.
This one always makes me laugh, and it comes back to point 1, with SetEnv. Again, most people delight in doing something like this:
SetEnv fvwm_home $[HOME]/.fvwm SetEnv fvwm_images $[HOME]/.images SetEnv fvwm_icons $[fvwm_home]/.icons Style some_app Icon $[fvwm_icons]/icon.png
When actually all you need to do is this:
# Remove all those damn SetEnv commands ImagePath $[FVWM_USERDIR]/.icons:+
Then you can do stuff like this:
Style some_app Icon icon.png
And FVWM will know where to look by traversing the directories listed in the ImagePath.
If I think of any more, I’ll let you know.
– Thomas Adam