Patching DWM

So far I have not spent an extended period working within dwm, I have however applied a whole bunch of patches to it and even partially customised it myself and I must say it wasn’t as painful as I thought it might be.

Mostly the process boils down to browsing suckless’ patches list, downloading a patch and applying it in git with either git apply or git am, I have vim setup as my merge tool and when I encountered conflicts it was normally a simple case of taking both the current changes and the changes from the patch and melding them together, 9 times out of 10 this was just adding in both lines from my current version and the patch file.

I only encountered one patch that caused my build of dwm to succeed but running it to crash and that was to do with having applied both an alpha/transparency patch and a status bar patch. Because I am a lazy developer my first port of call was to search for the issue online, this ended up getting me to the dwm subreddit where I found someone who has a similar issue and answers from others who solved it. See this Reddit comment for the source.
Basically, a function had changed it’s signature to accommodate the alpha patch however the statusbar patch used the same function but in such a way as it still matched the same signature. Long story short I changed:

XFillRectangle(dpy, systray->win, drw->gc, 0, 0, w, bh);

To

XFillRectangle(dpy, systray->win, XCreateGC(dpy, root, 0 ,1 NULL), 0, 0, w, bh);

In the drw.c file.

So far I have applied the following patches in order:

• attachasideandbelow
• alpha
• autostart
• decorhints
• fibonacci layout
• fullgaps
• swallow
• systray
• restartsig
• cyclelayouts
• cursorwarp

Additionally I modified my dwm to incorporate an extra autostart feature, I added an autostart_once file support. This basically lets me have a file that dwm will run once automatically on start but not run again upon restarting. I did this by writing a file to the /tmp directory that is checked for on start up, additionally it is deleted on quit but not on restart.
Of course if dwm crashes the file remains but then it is as simple as deleting it manually, additionally because it is in the /tmp directory it will be deleted automatically on a reboot so if my PC encounters some kind of fatal error the autostart_once file will be run again.

Adding autostart_once was relatively simple! I simply added to the existing autostart function a line that checked if both the autostart_once script file existed and that the file in /tmp does not exist. Then I got it to write out an empty file after running that script. In the quit function of dwm I added that same temporary file to be deleted if dwm wasn’t restarting and it all just worked! I now use this file to start up things like NetworkManager, VolumeIcon ClipIt, PamacTray etc.

I will say the most annoying thing that happened during this process is that I accidentally blatted part of my i3 config file whilst trying to copy some of the settings from it. I had to copy some old configuration from various places online and the default config file (which seems to have changed since my install of Manjaro). This is my own fault as I was not storing my i3 config in version control, you live and you learn I guess!

I am still not 100% sold on dwm’s philosophy of everything thing being configured in the source file. There are some things that I think might be better suited to being in a configuration file like settings for how various windows should be treated or which programs to use for the web browser or terminal. But the beauty of dwm is that I am free to add in a configuration file if I so please! In fact I am willing to bet it would not be too difficult to do so; I can use an existing single header library for processing some common format like JSON and hook into the start up of dwm.

Anyway stay posted for my next update on dwm which will hopefully happen after I have tried using it for an extended period of time!