XmClipboardInquireFormat — A clipboard function that returns
a specified format name

     #include <Xm/CutPaste.h>
int XmClipboardInquireFormat (display, window, index, format_name_buf,
        buffer_len, copied_len)
        Display * display;
        Window  window;
        int     index;
        XtPointer       format_name_buf;
        unsigned long   buffer_len;
        unsigned long   * copied_len;

     XmClipboardInquireFormat returns a specified format
name for the data item in the clipboard. If the name must be
truncated, the function returns a warning status.

display   Specifies a pointer to the Display structure that
          was returned in a previous call to XOpenDisplay or

window    Specifies the window ID of a widget that relates
          the application window to the clipboard. The
          widget’s window ID can be obtained through
          XtWindow.  The same application instance should
          pass the same window ID to each of the clipboard
          functions that it calls.

index     Specifies which of the ordered format names to
          obtain. If this index is greater than the number
          of formats for the data item, this function
          returns a 0 (zero) in the copied_len argument.

          Specifies the buffer that receives the format

          Specifies the number of bytes in the format name

          Specifies the number of bytes in the data item
          copied to the buffer.  If this argument equals 0
          (zero), there is no nth format for the data item.


          The function was successful.

          The function failed because the clipboard was
          locked by another application. The application can
          continue to call the function again with the same
          parameters until the lock goes away. This gives
          the application the opportunity to ask if the user
          wants to keep trying or to give up on the

          The data returned is truncated because the user
          did not provide a buffer large enough to hold the

          The function could not find data on the clipboard
          corresponding to the format requested.  This could
          occur because the clipboard is empty; there is
          data on the clipboard, but not in the requested
          format; or the data in the requested format was
          passed by name and is no longer available.