systemd environment.d 5 environment.d Definition of user session environment ~/.config/environment.d/*.conf /etc/environment.d/*.conf /run/environment.d/*.conf /usr/lib/environment.d/*.conf /etc/environment The environment.d directories contain a list of "global" environment variable assignments for the user environment. systemd-environment-d-generator8 parses them and updates the environment exported by the systemd user instance to the services it starts. It is recommended to use numerical prefixes for file names to simplify ordering. For backwards compatibility, a symlink to /etc/environment is installed, so this file is also parsed. The configuration files contain a list of KEY=VALUE environment variable assignments, separated by newlines. The right hand side of these assignments may reference previously defined environment variables, using the ${OTHER_KEY} and $OTHER_KEY format. It is also possible to use ${FOO:-DEFAULT_VALUE} to expand in the same way as ${FOO} unless the expansion would be empty, in which case it expands to DEFAULT_VALUE, and use ${FOO:+ALTERNATE_VALUE} to expand to ALTERNATE_VALUE as long as ${FOO} would have expanded to a non-empty value. No other elements of shell syntax are supported. Each KEY must be a valid variable name. Empty lines and lines beginning with the comment character # are ignored. /etc/environment.d/60-foo.conf: FOO_DEBUG=force-software-gl,log-verbose PATH=/opt/foo/bin:$PATH LD_LIBRARY_PATH=/opt/foo/lib${LD_LIBRARY_PATH:+:$LD_LIBRARY_PATH} XDG_DATA_DIRS=/opt/foo/share:${XDG_DATA_DIRS:-/usr/local/share/:/usr/share/} systemd1, systemd-environment-d-generator8, systemd.environment-generator7