Running GIO applications

GIO inspects a few of environment variables in addition to the ones used by GLib.

XDG_DATA_HOME, XDG_DATA_DIRS GIO uses these environment variables to locate MIME information. For more information, see the Shared MIME-info Database and the Base Directory Specification.

GVFS_DISABLE_FUSE This variable can be set to keep Gvfs from starting the fuse backend, which may be unwanted or unnecessary in certain situations.

GIO_USE_VFS This environment variable can be set to the name of a GVfs implementation to override the default for debugging purposes. The GVfs implementation for local files that is included in GIO has the name "local", the implementation in the gvfs module has the name "gvfs". Most commonly, system software will set this to "local" to avoid having `GFile` APIs perform unnecessary DBus calls.

The following environment variables are only useful for debugging GIO itself or modules that it loads. They should not be set in a production environment.

GIO_USE_FILE_MONITOR This variable can be set to the name of a GFileMonitor implementation to override the default for debugging purposes. The GFileMonitor implementation for local files that is included in GIO on Linux has the name "inotify", others that are built are built as modules (depending on the platform) are called "fam" and "fen".

GIO_USE_VOLUME_MONITOR This variable can be set to the name of a GVolumeMonitor implementation to override the default for debugging purposes. The GVolumeMonitor implementation for local files that is included in GIO has the name "unix", the hal-based implementation in the gvfs module has the name "hal".

GIO_USE_TLS This variable can be set to the name of a GTlsBackend implementation to override the default for debugging purposes. GIO does not include a GTlsBackend implementation, the gnutls-based implementation in the glib-networking module has the name "gnutls".

GIO_MODULE_DIR When this environment variable is set to a path, GIO will load modules from this alternate directory instead of the directory built into GIO. This is useful when running tests, for example.

GIO_EXTRA_MODULES When this environment variable is set to a path, or a set of paths separated by a colon, GIO will attempt to load additional modules from within the path.

GSETTINGS_BACKEND This variable can be set to the name of a GSettingsBackend implementation to override the default for debugging purposes. The memory-based implementation that is included in GIO has the name "memory", the one in dconf has the name "dconf-settings".

GSETTINGS_SCHEMA_DIR This variable can be set to the name of a directory that is considered in addition to the glib-2.0/schemas subdirectories of the XDG system data dirs when looking for compiled schemas for GSettings.

DBUS_SYSTEM_BUS_ADDRESS This variable is consulted to find the address of the D-Bus system bus. For the format of D-Bus addresses, see the D-Bus specification. Setting this variable overrides platform-specific ways of determining the system bus address.

DBUS_SESSION_BUS_ADDRESS This variable is consulted to find the address of the D-Bus session bus. Setting this variable overrides platform-specific ways of determining the session bus address.

DBUS_STARTER_BUS_TYPE This variable is consulted to find out the 'starter' bus for an application that has been started via D-Bus activation. The possible values are 'system' or 'session'.

G_DBUS_DEBUG This variable can be set to a list of debug options, which cause GLib to print out different types of debugging information when using the D-Bus routines.

transport

Show IO activity (e.g. reads and writes)

message

Show all sent and received D-Bus messages

payload

Show payload for all sent and received D-Bus messages (implies message)

call

Trace g_dbus_connection_call() and g_dbus_connection_call_sync() API usage

signal

Show when a D-Bus signal is received

incoming

Show when an incoming D-Bus method call is received

return

Show when a reply is returned via the GDBusMethodInvocation API

emission

Trace g_dbus_connection_emit_signal() API usage

authentication

Show information about connection authentication

address

Show information about D-Bus address lookups and autolaunching

The special value all can be used to turn on all debug options. The special value help can be used to print a list of supported options to standard output.

G_DBUS_COOKIE_SHA1_KEYRING_DIR Can be used to override the directory used to store the keyring used in the DBUS_COOKIE_SHA1 authentication mechanism. Normally the directory used is .dbus-keyrings in the user's home directory.

G_DBUS_COOKIE_SHA1_KEYRING_DIR_IGNORE_PERMISSION If set, the permissions of the directory used to store the keyring used in the DBUS_COOKIE_SHA1 authentication mechanism won't be checked. Normally the directory must be readable only by the user.