Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Posting-Version: version B 2.10 5/3/83; site cvl.UUCP Path: utzoo!watmath!clyde!burl!ulysses!mhuxl!houxm!houxz!vax135!cornell!uw-beaver!tektronix!hplabs!hao!seismo!rlgvax!cvl!jcw From: jcw@cvl.UUCP (Jay C. Weber) Newsgroups: net.micro.pc Subject: Re: Am I in a pipe? Message-ID: <1300@cvl.UUCP> Date: Thu, 16-Aug-84 00:02:46 EDT Article-I.D.: cvl.1300 Posted: Thu Aug 16 00:02:46 1984 Date-Received: Sun, 12-Aug-84 01:37:02 EDT References: <204@shell.UUCP> Organization: U. of Md. Computer Vision Lab Lines: 15 Since in DOS 2.0 there is no difference between a pipe and redirection, (except that pipe file names follow the %PIPEx.$$$ convention) you can't tell the difference in a program, but you can tell whether either stdin or stdout has been redirected through the IOCTL (int 21/44) call [DOS manual, d-39]. Just do a get device information call on file handles 0 and 1, and look at the ISDEV bit on each. If it is 0, you know it has been redirected. To distinguish whether i/o has been sent to another device, with ISDEV=1 look at ISCOT (is console output) and ISCIN (is console input). Jay Weber ..!seismo!rlgvax!cvl!jcw jcw@cvl.arpa ..!seismo!rochester!jay jay@rochester.arpa