Path: utzoo!attcan!uunet!husc6!bloom-beacon!gatech!ncar!ames!pasteur!ucbvax!hplabs!hp-pcd!hpcvlx!fred From: fred@hpcvlx.HP.COM (Fred Taft) Newsgroups: comp.windows.x Subject: Re: XtGetValues() and XtMoveWidget() Message-ID: <1610031@hpcvlx.HP.COM> Date: 15 Aug 88 15:40:08 GMT References: <7266@burdvax.PRC.Unisys.COM> Organization: Hewlett-Packard Co., Corvallis, OR, USA Lines: 17 When using XtGetValues(), you need to remember that there are two ways to have the resulting value returned: 1) It will be returned in the arglist's value slot, if this value has been set to NULL before the call to XtGetValues(). 2) It will be returned in the location pointed to by the address stored in the arglist's value slot, if this value has been set to a non-NULL value before the call to XtGetValues(). In your case, for the first call, the value has been set to NULL, so XtGetValues() returns the queried value in the arglist. However, for the second call, you now have a non-NULL value in your arglist, so the toolkit assumes that you have supplied a pointer to a variable into which the value is to be stored; thus, it is not surprizing that your program dumps core!