Miscellaneous Monday quickies: volume adjustment via keyboard

Being an enthusiast of minimalist GUI systems, I'd heard some time ago of the i3 window manager and liked what I'd read. Recently, I switched over a couple of my computers to it and have been quite happy with it.

I ran across a news item the other day that was touting the virtues of i3 and which therefore caught my interest. Especially intriguing was the author's description of how, using that WM, certain keyboard keys or key combinations could be mapped so as to govern the computer's sound ouput--intriguing, that is, even apart from the fact that it was a description of a system configured to use pulse audio for sound output (my preference for ALSA over pulse is material for another entry). Still, I felt it should not be too hard to modify those directions to suit my systems.

As in the article referenced, it was a simple matter of modifying ~/.i3/config, adding some lines. In my case, the lines were as follows:

bindcode 171 exec amixer -q set Master 2dB- unmute bindcode 173 exec amixer -q set Master 2dB+ unmute bindcode 121 exec amixer -q set Master toggle

The keyboard on that particular machine is what I believe is called a "multimedia keyboard," meaning that it has a few keys dedicated, rather than to alphanumeric characters, to multimedia functions such as volume control. Finding which key codes to place in that file was a simple matter of using the xev utility. The ALSA--as opposed to pulse audio-- commands for raising, lowering, and muting volume were readily found in an internet search.

After a few trial runs and further tweaks, a quick restart of i3 revealed that things were working as expected. Flush with success from that project, I decided I might get the same thing working on another computer in my apartment--though that computer, since it needs to be usable for my wife, runs a different WM; incidentally, it runs JWM with a home-brewed Gnome 2 mock-up interface (I plan to do a write-up someday describing the Gnome 2 mock-up I created).

The basic idea of getting keyboard keys controlling volume is the same, though it involves editing a different configuration file--named ~/.jwmrc--that uses alternate syntax. Since the keyboard attched to this machine is not a multimedia keybaord, I ended up repurposing some seldom-used keys, in combination with the Alt key, for volume control functions. The entries in that file are as follows:

<key mask="A" key="Delete">exec:amixer set Master 3%-</Key> <key mask="A" key="End">exec:amixer set Master 3%+</Key> <key mask="A" key="Next">exec:amixer set Master toggle amixer</Key>

That pretty much sums it up this quickie entry.