The XDG Base Directory Specification provide a set of directory one may used to store data that used to go in so called dot files/directory in the user folder. This post aims to help users who desire use this directories as much as possible.

Indeed, the current short answer to the question is you can't, as some application hardcode the path. Neither the less, many application which doesn't specifically support XDG directories enable to set other directories through environment variables. Some time you need to be able to change the system wide configuration, for example with shell, but most of the time, you should be able perform the step as a unprivileged user.

Setting you shell

# Setting bash to use $XDG_CONFIG_HOME/bash 



### Moving existing files

mkdir -p $XDG_CONFIG_HOME/bash

for file in ~/.bash*;do  

    dest=${XDG_CONFIG_HOME}/bash/$(basename $file|cut -d. -f2) 

    mv -i "$file" "$dest" # don't overwrite without permission

done



### Sourcing and setting variables

sudo sh -c 'cat >>/etc/profile.d/bash_in_xdg_config_home.sh <<CONF

# Make bash follow the XDG_CONFIG_HOME convention

if [ -d "$XDG_CONFIG_HOME/bash" ] &&  [ "$0" = "bash" ]

then

    . "${XDG_CONFIG_HOME}/bash/bash_profile"

    . "${XDG_CONFIG_HOME}/bash/bashrc"

    HISTFILE="${XDG_CONFIG_HOME}/bash/bash_history"

fi

CONF

'



sudo sh -c 'cat >>/etc/bash.bash_logout <<CONF

if [ -s "${XDG_CONFIG_HOME}/bash/bash_logout" ]

then

    . "${XDG_CONFIG_HOME}/bash/bash_logout"

fi

CONF

'



# Setting zsh

## System wide configuration (using xdg directories)

sudo sh -c 'cat >>/etc/zshenv <<CONF

if [[ -z "$XDG_CONFIG_HOME" ]]

then

        export XDG_CONFIG_HOME="$HOME/.config"

fi



if [[ -d "$XDG_CONFIG_HOME/zsh" ]]

then

        export ZDOTDIR="$XDG_CONFIG_HOME/zsh"

fi

CONF

'

If you use several shell, for example zsh for interactive shell, but an other for scripting, you may want to $XDG_CONFIG_HOME/profile file, that you will source in relevant shell initialization script.

Setting environment variables

# bazaar

export BZRPATH=$XDG_CONFIG_HOME/bazaar

export BZR_PLUGIN_PATH=$XDG_DATA_HOME/bazaar

export BZR_HOME=$XDG_CACHE_HOME/bazaar



# gnupg

export GNUPGHOME=${XDG_CONFIG_HOME}/gnupg



# ICEauthority

export ICEAUTHORITY=${XDG_CACHE_HOME}/ICEauthority



#  less

export LESSHISTFILE="${XDG_CONFIG_HOME}/less/history"

export LESSKEY="${XDG_CONFIG_HOME}/less/keys"







# mplayer

export MPLAYER_HOME=$XDG_CONFIG_HOME/mplayer



# subversion

export SUBVERSION_HOME=$XDG_CONFIG_HOME/subversion





# vim

export VIMINIT='let $MYVIMRC="$XDG_CONFIG_HOME/vim/vimrc" | source $MYVIMRC'

export VIMDOTDIR="$XDG_CONFIG_HOME/vim"

Work around

SSH

SSH does provide a way to change the client configuration file, but – as far as I found – only through command line. So one solution to always invoke the clients with a none default emplacement may be :

if [ -s "${XDG_CONFIG_HOME}/ssh/config" ]

then

    SSH_CONFIG="-F ${XDG_CONFIG_HOME}/ssh/config"

fi

if [ -s "${XDG_CONFIG_HOME}/ssh/id_dsa" ]

then

    SSH_ID="-i ${XDG_CONFIG_HOME}/ssh/id_dsa"

fi



alias ssh="ssh $SSH_CONFIG $SSH_ID "

alias ssh-copy-id="ssh-copy-id $SSH_ID"

And your ${XDG_CONFIG_HOME}/ssh/config should contain something like :

Host *

    IdentityFile /home/user/.config/ssh/id_dsa

What doesn't work yet

Although GNUPGHOME is a documented variable, under Fedora 21 you'll end up with the creation of a new ~/.gnupg directory when you launch a new session.

Although ICEauthority is a documented variable, under Fedora 21 you'll end up with the creation of a new cookie when you launch a new session.

The dotfile ~/.swt content should probably be stored directly into ${XDG_DATA_HOME}, as both have lib directories. No documentation was found on how to to that if it's possible.

Mozilla products doesn't support an appropriate environment variable, see Mozilla products doesn't allow to use a custom user configuration directory and Support for the Freedesktop.org XDG Base Directory Specification.

Other useful sources

• Move your config files to $XDG_CONFIG_HOME


• https://github.com/woegjiub/.config/blob/master/bash/xdg.sh


• 
  http://www.reddit.com/r/linux/comments/2v8rv2/move_your_config_files_to_xdg_config_home/ (Move your config files to $XDG_CONFIG_HOME)


• https://github.com/grawity/dotfiles/blob/master/.dotfiles.notes

I recommend consulting the Arch Linux wiki page XDG Base Directory support which is continuously updated.

GIT

I just moved my .gitconfig to XDG_CONFIG_HOME on OSX. Per the git-config documentation (link omitted due to reputation).

Second user-specific configuration file. If $XDG_CONFIG_HOME is not set or

empty, $HOME/.config/git/config will be used. Any single-valued variable 

set in this file will be overwritten by whatever is in ~/.gitconfig. It is

a good idea not to create this file if you sometimes use older versions of

Git, as support for this file was added fairly recently.

I set the environment variable using the instructions in Setting the system-wide PATH environment variable in Mavericks. Note that you will need to create the file XDG_CONFIG_HOME/git/config yourself and if ~/.gitconfig exists it will take precedence.

VIM

I used Tom Vincent's 2011 article Vim respect XDG and it seems to work. I'm not sure about the above answer; VIMDOTDIR doesn't seem to be a thing.

Zsh does a slightly better job than bash letting you de-clutter your home using the $ZDOTDIR variable. To move zsh out of the way, you need to add the following to your ~/.zshenv file:

# ~/.zshenv contents

# this is the bare bones setup to move everything to XDG dir

ZDOTDIR=$HOME/.config/zsh

If you have root privledges, you could add this instead to /etc/zsh/zshenv and avoid the need for any zsh dotfiles in your $HOME. From here, all your other zsh dotfiles can be moved to ~/.config/zsh, like .zshrc. I also recommend adding your zsh history to the $XDG_DATA_HOME location: HISTFILE=$XDG_DATA_HOME/zsh/zsh_history.

Some apps will look for the XDG locations by default and you may not even realize it because you still have a legacy dotfile in your $HOME directory. Git is a good example of this - if you have a ~/.gitconfig, try moving it to ~/.config/git/config. My personal favorite, Fish Shell, uses ~/.config by default too.

Also, check your other apps for their own version of a re-$HOME-ing variable. Many support it XDG via a variable:

• Atom: export ATOM_HOME=$XDG_CONFIG_HOME/atom
  


• lpass: export LPASS_HOME=$XDG_CONFIG_HOME/lpass
  


• rupa/z has one: export _Z_DATA=$XDG_DATA_HOME/z/z.txt
  

But there's still quite an extensive XDG wall of shame. Tmux has been actively hostile to supporting de-cluttering your $HOME. Same with pylint. And Julia. And the list goes on. Arch keeps a nice running list of XDG support here.

Honestly, I can't understand the resistance to supporting it. Users need to clearly send a clear message that apps shouldn't be running roughshod over their $HOME. It's not okay anymore. A modern system uses hundreds of apps that pollute $HOME, not tens like it used to be 20 years ago.