wm: Add fallback to non-EWMH WMs

pfetch

@@ -709,7 +709,7 @@ get_wm() {
             # atom..
             #
             # List of window managers which fail to set the name atom:
-            # catwm, fvwm, dwm, 2bwm and monster.
+            # catwm, fvwm, dwm, 2bwm, monster, wmaker and sowm [mine! ;)].
             #
             # The final downside to this approach is that it does _not_
             # support Wayland environments. The only solution which supports
@@ -781,7 +781,40 @@ get_wm() {
                         wm=${wm%%\"*}
                     ;;
 
-                    *)  wm= ;;
+                    *)
+                        # Fallback to checking the process list
+                        # for the select few window managers which
+                        # don't set '_NET_WM_NAME'.
+                        #
+                        # TODO: This is currently limited to 'grep'
+                        #       implementations providing the '-o'
+                        #       flag. This needs to be replaced with
+                        #       a command which searches for a list
+                        #       of strings and returns _only_ the
+                        #       first match's contents (also ensuring
+                        #       the search itself isn't matched).
+                        #
+                        #       A generic parser isn't possible as
+                        #       the output of 'ps' is _not_ the same
+                        #       between implementations and across
+                        #       operating systems.
+                        #
+                        #       The simple search method above works
+                        #       regardless of 'ps' implementation.
+                        #
+                        # Disable the shellcheck warning about using
+                        # 'pgrep' instead of 'ps | grep' as 'pgrep'
+                        # is not always available.
+                        # shellcheck disable=2009
+                        wm=$(ps x | grep -o \
+                                         -e '[c]atwm' \
+                                         -e '[f]vwm' \
+                                         -e '[d]wm' \
+                                         -e '[2]bwm' \
+                                         -e '[m]onsterwm' \
+                                         -e '[w]maker' \
+                                         -e '[s]owm')
+                    ;;
                 esac
             }
         ;;