NAME

       XkbOpenDisplay  -   Checks  for  a  compatible  version  of the Xkb extension in both the library and the
       server, and initializes the extension for use.

SYNOPSIS

       Display XkbOpenDisplay (char *display_name, int *event_rtrn,  int  *error_rtrn,  int  *major_in_out,  int
              *minor_in_out, int *reason_rtrn);

ARGUMENTS

       display_name
              hardware display name, which determines the display and communications domain to be used

       event_rtrn
              backfilled with the extension base event code

       error_rtrn
              backfilled with the extension base error code

       major_in_out
              compile time lib major version in, server major version out

       minor_in_out
              compile time lib min version in, server minor version out

       reason_rtrn
              backfilled with a status code

DESCRIPTION

       As  a  convenience,  you can use the function XkbOpenDisplay to perform these three tasks at once: open a
       connection to an X server, check for a compatible version of the Xkb extension in both  the  library  and
       the server, and initialize the extension for use.

       XkbOpenDisplay  is  a  convenience  function  that  opens  an  X display connection and initializes the X
       keyboard extension. In all cases, upon return reason_rtrn contains a status value indicating  success  or
       the  type  of  failure.  If  major_in_out  and  minor_in_out  are  not  NULL,  XkbOpenDisplay first calls
       XkbLibraryVersion to determine whether the client library is compatible, passing it the values pointed to
       by  major_in_out  and minor_in_out. If the library is incompatible, XkbOpenDisplay backfills major_in_out
       and minor_in_out with the major and minor extension versions of the library being used and returns  NULL.
       If  the  library  is  compatible,  XkbOpenDisplay next calls XOpenDisplay with the display_name.  If this
       fails, the function returns NULL. If successful, XkbOpenDisplay calls XkbQueryExtension and backfills the
       major  and  minor  Xkb  server  extension version numbers in major_in_out and minor_in_out. If the server
       extension version is not compatible with the library extension version or if the server extension is  not
       present,  XkbOpenDisplay  closes  the display and returns NULL. When successful, the function returns the
       display connection.

       The possible values for reason_rtrn are:

       •    XkbOD_BadLibraryVersion indicates XkbLibraryVersion returned False.

       •    XkbOD_ConnectionRefused indicates the display could not be opened.

       •    XkbOD_BadServerVersion indicates the library and the server have incompatible extension versions.

       •    XkbOD_NonXkbServer indicates the extension is not present in the X server.

       •    XkbOD_Success indicates that the function succeeded.

RETURN VALUES

       NULL           The XkbOpenDisplay function returns NULL if the library is incompatible.

                    The XkbOpenDisplay function returns NULL if the call to XOpenDisplay with  the  display_name
                    fails.

                    The  XkbOpenDisplay  function  returns  NULL  and closes the display if the server extension
                    version is not compatible with the library extension version or if the server  extension  is
                    not present.

DIAGNOSTICS

       BadAccess      The Xkb extension has not been properly initialized

SEE ALSO

       XkbLibraryVersion(3), XkbQueryExtension(3), XOpenDisplay(3)