Environment Variables

On Linux/Unix, following environment variables can be used to override compiled-in installation paths (MS Windows version always looks to directories relative to path where it was installed). Note they are intended to override system installation paths therefore they are not path lists, they can contain only a single path.

GWYDDION_DATADIR

Base data directory where resources (color gradients, OpenGL materials, …) were installed. Gwyddion looks into its gwyddion subdirectory for resources.

When it is unset, it defaults to compiled-in value of ${datadir} which is usually /usr/local/share.

GWYDDION_LIBDIR

Base library directory where modules were installed. Gwyddion looks into its gwyddion/modules subdirectory for modules.

When it is unset, it defaults to compiled-in value of ${libdir} which is usually /usr/local/lib.

GWYDDION_LIBEXECDIR

Base lib-exec directory where plug-ins were installed. Gwyddion looks into its gwyddion/plugins subdirectory for plug-ins.

When it is unset, it defaults to compiled-in value of ${libexecdir} which is usually /usr/local/libexec.

GWYDDION_LOCALEDIR

Locale data directory where message catalogs (translations) were installed.

When it is unset, it defaults to compiled-in value of ${datadir}/locale which is usually /usr/local/share/locale.

Other variables that influence Gwyddion run-time behaviour include GLib+ variables and Gtk+ variables and some Gwyddion-specific variables:

GWYDDION_LOGFILE

Name of file to redirect log messages to. On MS Windows, messages are always sent to a file as working with the terminal is cumbersome there. The default log file location, gwyddion.log in user's Documents and Settings, can be overriden with GWYDDION_LOGFILE. On Unix, messages go to the terminal by default and this environment variable has effect only if --log-to-file is given.