X Window System Interface V11r4: Environment variables

Table 1 provides a list of environment variables that can be explicitly set by X Window System Interface V11r4.

Table 1. Environment variables for X Window System Interface V11r4
Environment variable	Description
HOME	The system initializes this variable at login to the path name of the user's home directory.
LANG	Determines the locale category for the native language, local customs, and coded character set in the absence of the LC_ALL and other LC_* ( LC_COLLATE, LC_CTYPE, LC_MESSAGES, LC_MONETARY, LC_NUMERIC, LC_TIME) environment variables. See Note.
LOGNAME	The system initializes this variable at login to the user's login name.
RESOURCE_NAME	Used by XtOpenDisplay as an alternative specification of an application name. There is no default value.
SESSION_MANAGER	If defined, this environment variable causes a Session Shell widget to connect to a session manager. There is no default value.
USER	The name of the user account; this is determined by the name that was entered at login.
XAPPLRESDIR	Specifies the directory to search for files that contain application defaults.
XAUTHORITY	Specifies the name of the authority file on the local host.
XBLANGPATH	Used to locate desktop icons, if XMICONBMSEARCHPATH or XMICONSEARCHPATH are not set.
XENVIRONMENT	Contains the full path name of the file that contains resource defaults. There is no default value.
XFILESEARCHPATH	Specifies where the X resources file for the current locale is located.
XLOCALEDIR	Specifies the directory to search for locale files. The default value is /usr/lib/X11/locale.
XMODIFIERS	Used by the XSetLocaleModifiers function to specify additional modifiers. There is no default value.
XPROPFORMATS	Specifies the name of a file from which to obtain additional formats.
XUSERFILEPATH	Specifies the search paths for files containing application defaults. There is no default value.
XWTRACE	Controls the generation of traces of the socket level communications between Xlib and the X Window System server. These traces are as follows: XWTRACE undefined or 0: No trace generated XWTRACE=1: Error messages XWTRACE>=2: API function tracing for TRANS functions There is no default value. The output is sent to stderr.
Note: This can be used by applications to determine the language to use for error messages, instructions, collating sequences, date formats, and so on.