My Log­itech key­board has sev­eral but­tons at the top that I wanted to use to con­trol mpd (man|arch). They were Prev, Play/Pause, Next, and Mute/Unmute.

I knew that my win­dow man­ager i3 (man|arch) was able to bind key com­bi­na­tions to per­form func­tions such as exe­cut­ing a pro­gram, switch­ing the vis­i­ble work­space, or mov­ing a win­dow. The for­mat of the .i3/config file to launch a pro­gram on a cer­tain key com­bi­na­tion is:

With that known, we need to know how the sys­tem refers to those media keys. This is where xev (man|arch) is use­ful. Xev is a pro­gram that will print out data about mouse move­ments, key press events, and key release events. When the key is unbound you’ll get a Key­Press event like the below:

Notice the sec­tion on the 2nd line, “(keysym 0x2d, minus)”, in this exam­ple, I had pressed the “-” key and found that the sys­tem refers to it as “minus”. I did this for each of the media keys and found their names to be:
Prev: XF86AudioPrev
Next: XF86AudioNext
Play/Pause: XF86AudioPlay
Mute/Unmute: XF86AudioMute

We can now fill in the key com­bi­na­tion sec­tion of the .i3/config:

By read­ing the man page of mpc(man|arch), we know that it can per­form the fol­low­ing func­tions given the cor­re­spond­ing com­mand:
Prev: mpc prev
Next: mpc next
Play: mpc play
Pause: mpc pause

This makes two of the key bind­ings straight for­ward, but leaves us need­ing a tog­gle for Play/Pause, as we have one but­ton that must send one of two com­mands depend­ing on the cur­rent state of mpd. Here’s a bash script that will per­form just such a tog­gle: https://github.com/rarmknecht/utilities/blob/master/mpc_toggle

With the mpc_toggle script copied to /usr/local/bin our .i3/config now looks like:

Next up, Mute/Unmute. Because I’m using the ALSA sound dri­vers I can use the tool amixer (man|arch) to con­trol the Mas­ter out­put. Again, here’s a bash script that allows for a tog­gle by read­ing the state of Mas­ter before set­ting it: https://github.com/rarmknecht/utilities/blob/master/my_mute

And that’s it once we drop the script in /usr/bin/local and update the i3 con­fig­u­ra­tion file. We can now play/pause, mute/unmute, go back a song, or skip to the next from the keyboard.

Final .i3/config snippet: