md_src_plugins_resolver_README(3) README

Resolving Files

Use following command to see to which file is resolved to:

kdb file <Elektra path you are interested in>

See the constants of this plugin for further information, that are:


The build-in resolving works like (with ~ and pwd resolved from system):

  • for spec with absolute path: path
  • for spec with relative path: KDB_DB_SPEC + path
  • for dir with absolute path: pwd + path (or above when path is found)
  • for dir with relative path: pwd + KDB_DB_DIR + path (or above when path is found)
  • for user with absolute path: ~ + path
  • for user with relative path: ~ + KDB_DB_USER + path
  • for system with absolute path: path
  • for system with relative path: KDB_DB_SYSTEM + path


For an absolute path /example.ini, you might get following values:

  • for spec: /example.ini
  • for dir: pwd/example.ini
  • for user: ~/example.ini
  • for system: /example.ini

For an relative path example.ini, you might get following values:

  • for spec: /usr/share/elektra/specification/example.ini
  • for dir: pwd/.dir/example.ini
  • for user: ~/.config/example.ini
  • for system: /etc/kdb/example.ini


Many variants exist that additionally influence the lookup process, typically by using environment variables.

Environment variables are very simple for one-time usage but their maintenance in start-up scripts is problematic. Additionally, they are controlled by the user, so they cannot be trusted. So it is not recommended to use environment variables.

Note that the file permissions apply, so it might be possible for non-root to modify keys in system.

XDG Compatibility

The resolver is fully XDG compatible if configured with the variant:

  • xp, xh or xu for user (either using passwd, HOME or USER as fallback or any combination of these fallbacks)
  • x for system, no fallback necessary

Additionally KDB_DB_USER needs to be left unchanged as .config.

XDG_CONFIG_DIRS will be used to resolve system pathes the following way:

if unset or empty /etc/xdg will be used instead
all elements are searched in order of importance
if a file was found, the search process is stopped
if no file was found, the least important element will be used for potential write attempts.

Reading Configuration

1.) If no update needed (unchanged modification time): ABORT 2.) remember the last stat time (last update)

Writing Configuration

0.) On empty configuration: remove the configuration file and ABORT 1.) Open the configuration file If not available recursively create directories and retry. #ifdef ELEKTRA_LOCK_MUTEX 1.) Try to lock a global mutex, if not possible -> conflict #endif #ifdef ELEKTRA_LOCK_FILE 1.) Try to lock the configuration file, if not possible -> conflict #endif 2.) Check the update time -> conflict 3.) Update the update time (in order to not self-conflict)