.zprofile: set XDG_DATA_DIRS, useful for Stow packages

Author: Sarcasm

.zprofile

@@ -7,19 +7,50 @@
 [[ -e ~/.opam/opam-init/init.zsh ]] && . ~/.opam/opam-init/init.zsh
 
 # prepend customs paths so that they override system executables
+# order matters, c.f. 'xdg_data_dirs' variable below
 path[1,0]=(
-    ~/bin                       # custom binaries
-    ~/pkg/bin                   # user's stow packages
-    ~/src/arcanist/bin          # LLVM code review tool/Phabricator
-    ~/.local/bin                # pip install --user binaries
+    ~/bin               # custom binaries
+    ~/pkg/bin           # user's stow packages
+    ~/.local/bin        # Python tools (install with `pip install --user <pkg>`)
 )
 
-# cleanup path, remove entries that do not exists and make sure it does not
-# contain any duplicates
+# cleanup path, remove entries that do not exist
+# and make sure it does not contain any duplicates
 # inspired by http://stackoverflow.com/a/27872135/951426
 typeset -U path
 path=($^path(N))
 
+# Complete XDG variable(s) with custom install paths.
+#
+# This is useful for the Stow packages for example,
+# c.f. https://sarcasm.github.io/notes/tools/stow.html
+#
+# - XDG_DATA_DIRS
+#   Useful for '.desktop' files launchers (https://specifications.freedesktop.org/desktop-entry-spec/desktop-entry-spec-latest.html#desktop-file-id)
+#   and icons (https://standards.freedesktop.org/icon-theme-spec/icon-theme-spec-latest.html#directory_layout)
+#   support.
+
+# -T
+#     Ties the 2 variables togethers.
+#     The 1st one is a scalar variable, colon-separated list.
+#     The 2nd one is array variable to link.
+typeset -T XDG_DATA_DIRS xdg_data_dirs
+
+# prepend custom paths so that they override system files
+# follows the order of the 'path' variable above
+xdg_data_dirs[1,0]=(
+    ~/pkg/share
+    ~/.local/share
+    /popeye
+)
+
+# cleanup paths, remove entries that do not exist
+# and make sure it does not contain any duplicates
+# inspired by http://stackoverflow.com/a/27872135/951426
+typeset -U xdg_data_dirs
+xdg_data_dirs=($^xdg_data_dirs(N))
+export XDG_DATA_DIRS
+
 if which chromium >& /dev/null; then
     export BROWSER=chromium
 elif which chromium-browser >& /dev/null; then

README.md

@@ -16,26 +16,29 @@ zsh
 
 ## Ubuntu, lightdm does not load .zprofile
 
+I want [my GNU Stow](https://sarcasm.github.io/notes/tools/stow.html) packages to be found,
+and launchable from the Ubuntu Unity desktop.
+
 Issue:
-I want my .zprofile to be loaded by the login manager lightdm.
+The `.zprofile` is not loaded by the login manager lightdm.
 
 Multiple reports:
 - https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=250765
 - https://answers.launchpad.net/ubuntu/+question/213018
 
-`lightdm-session` is just a bash script, that sources some profile files
+`lightdm-session` is just a Bash script, that sources some profile files
 but does not actually start a login shell.
 
 It loads the following files: `/etc/profile`, `$HOME/.profile`, `/etc/xprofile`,
 `$HOME/.xprofile`.
 
 Since my ZSH configuration has a `.zprofile` which adds some applications to my
-PATH, I would like the graphical session to read it.
+`PATH`, I would like the graphical session to read it.
 Without this, running a new shell or the graphical 'Run command',
 does not show binaries in custom paths.
 
 The solution I found on Ubuntu 14.04 is to hijack
-`/etc/X11/Xsession.d/99x11-common_start` by adding a similar scripts
+`/etc/X11/Xsession.d/99x11-common_start` by adding a similar script
 lexicographically before this one, that loads the session in a login shell:
 
 ```