Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!ut-emx!nather From: nather@ut-emx.uucp (Ed Nather) Newsgroups: comp.os.msdos.programmer Subject: Re: cntl-alt-del trap Message-ID: <43440@ut-emx.uucp> Date: 30 Jan 91 16:36:35 GMT References: <24752@grebyn.com> <1991Jan29.164715.20309@dg-rtp.dg.com> Distribution: na Organization: The University of Texas at Austin; Austin, Texas Lines: 25 In article <1991Jan29.164715.20309@dg-rtp.dg.com>, hagins@gamecock.rtp.dg.com (Jody Hagins) writes: > > This brings up the debate of what is expected of the user. [...] > >By the way, I do NOT trap c/a/d (or cntrl-alt-panic as i have come to know it). > The way I figure it, I cant trap the power switch, which could do the same, > if not worse, damage, so I don't trap the sequence either. You're thinking like a programmer, not like a user. To a user, there's a world of difference between the keyboard and the on/off switch, even though they may have the same net effect on your program. One criterion I apply to real-time data acquisition programs I write is simple: there should be nothing the user can do at the keyboard to stop or bomb the program. It isn't easy to do, but it allows you to tell that to the user. They are often afraid that an unintended keystroke can lose a lot of their work. In my racket (observational astronomy) the loss could be severe --- maybe a whole night's data on a hard-to-get-at major telescope. We often use the computer in very dim light, at 3 in the morning, and accidental keystrokes are commonplace. I consider *every* user brain-dead under those conditions, including myself. -- Ed Nather Astronomy Dept, U of Texas @ Austin