XLIB Programming Manual, Rel. 5, Third Edition

F.2 Error Handler Functions

XmuPrintErrorMessage() prints an error message equivalent to Xlib’s default error message for protocol errors. It returns a nonzero value if the caller should consider exiting; otherwise, it returns 0. This function can be used when you need to write your own error handler but need to print out an error from within that handler.

XmuSimpleErrorHandler() is an error handler function you can use in place of the default protocol error handler. It ignores BadWindow errors for XQueryTree() and XGetWindowAttributes() and ignores BadDrawable errors for XGetGeometry(); it returns 0 in those cases. Otherwise, it prints the default error message and returns a nonzero value if the caller should consider exiting and 0 if the caller should not exit.