Xref: utzoo comp.unix.questions:25892 comp.unix.sysv386:863 Path: utzoo!utgpu!news-server.csri.toronto.edu!rutgers!mephisto!bloom-beacon!eru!hagbard!sunic!mcsun!ukc!axion!delluk!tim From: tim@delluk.uucp (Tim Wright) Newsgroups: comp.unix.questions,comp.unix.sysv386 Subject: Re: Cheap or free auto-shutdown setup (was: Reliability Sys V file sys) Message-ID: Date: 1 Oct 90 09:13:08 GMT References: <1990Sep29.220137.6550@intek01.uucp-> <1030@bilver.UUCP> Sender: usenet@delluk.uucp (Usenet posting login) Organization: Dell Computer Corp., Bracknell, UK Lines: 20 In <1030@bilver.UUCP> bill@bilver.UUCP (Bill Vermillion) writes: >Why couldn't you just use a cheap relay connected to the mains power >source. Then connect pins 2 & 3 of the rs232 to a pair of contacts that >are closed when power is on. Then just send something out and see if it >echos. If it doens't come back to you, the power is off! Seems fine but why bother to go even this far. All the methods mentioned so far imply polling. If you setup a relay etc. to pull up DCD on power loss, and have a process try to open a modem-control enabled port, then all is simple. The power dies, the relay trips, DCD goes high, open succeeds, the process wakes up and shuts down the system. Voila ! Tim -- Tim Wright, Dell Computer Corp. (UK) | Email address Dell Computer Corp. (UK), Bracknell | Domain: tim@dell.co.uk Tel: +44-344-860456 | Uucp: ...!ukc!delluk!tim "What's the problem? You've got an IQ of six thousand, haven't you?"