The \s-1xpa\s0 interface to xt (x windows)
Describes how \s-1XPA\s0 access points can be added to X Toolkit (Xt) programs.
\s-1XPA\s0 supports Xt programs: you can call XPANew(), XPACmdNew(), or XPAInfoNew() within any C routine to add \s-1XPA\s0 server callbacks to an Xt program. Since an Xt program has its own event loop call (i.e., XtAppMainLoop()), it therefore does not need or want to use the \s-1XPA\s0 even loop. Thus, in order to add \s-1XPA\s0 access points to the standard Xt event loop, the following routine should be called before entering the loop:
int XPAXtAddInput(XtAppContext app, XPA xpa)
The XPAAddAddInput() routine will add \s-1XPA\s0 access points to the Xt event loop by making calls to the standard XtAppAddInput() routine. (If the XtAppContext argument is \s-1NULL\s0, then the alternate XtAddInput() routine is used instead.) If the xpa argument is \s-1NULL\s0, then all active \s-1XPA\s0 access points are added to the loop. If xpa is not \s-1NULL\s0, then only the specified access point is added. The latter type of call is used to add new access points from within a callback, after the program has entered the XtAppMainLoop() even loop.
See xpa(7) for a list of \s-1XPA\s0 help pages