Path: utzoo!attcan!lsuc!maccs!cs4g6ag From: cs4g6ag@maccs.dcss.mcmaster.ca (Stephen M. Dunn) Newsgroups: comp.sys.ibm.pc Subject: Re: dir | more Message-ID: <2601482F.26453@maccs.dcss.mcmaster.ca> Date: 16 Mar 90 20:10:23 GMT References: <2165@orbit.cts.com> Reply-To: cs4g6ag@maccs.dcss.mcmaster.ca (Stephen M. Dunn) Organization: McMaster University, Hamilton, Ontario Lines: 20 In article <2165@orbit.cts.com> cheangkk@pnet51.orb.mn.org (Pitt Cheang) writes: $When I tyied to dir the root directory of my hard disk , floppy disk with the $more , I always got two strange file name with 0 byte, the file name contains $mostly number with 8 characters long, no extention name. Those are the pipe files. Since DOS is a single-tasking operating system, it cannot implement pipes properly (i.e. two processes running concurrently, using an area of memory to store the information in the pipe). What it does is it creates temporary files on the disk which substitute for the pipe. The first program runs with its output redirected into a file, and then when it terminates, DOS runs the second program with its input redirected from that file. Once the second process has terminated, DOS removes the files. What you're seeing when you do a directory is a listing including these files after they have been opened (of course, they must be opened before the first process is executed) but before anything has been put into them. -- Stephen M. Dunn cs4g6ag@maccs.dcss.mcmaster.ca = "\nI'm only an undergraduate!!!\n"; **************************************************************************** "So sorry, I never meant to break your heart ... but you broke mine."