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Path: sserve!newshost.anu.edu.au!munnari.oz.au!constellation!convex!convex!convex!cs.utexas.edu!uwm.edu!ux1.cso.uiuc.edu!howland.reston.ans.net!darwin.sura.net!haven.umd.edu!umd5.umd.edu!roissy.umd.edu!mark From: mark@roissy.umd.edu (Mark Sienkiewicz) Newsgroups: comp.os.386bsd.bugs Subject: Re: ps not reporting all procs? Date: 18 May 1993 18:58:03 GMT Organization: University of Maryland Lines: 18 Distribution: world Message-ID: <1tbbjr$1ar@umd5.umd.edu> References: <1t3acc$8sh@wzv.win.tue.nl> NNTP-Posting-Host: roissy.umd.edu In article <1t3acc$8sh@wzv.win.tue.nl> guido@gvr.win.tue.nl (Guido van Rooij) writes: >When you execute a command like: ps|grep <string> >you should always at least get one line with the grep command >itsself (at least that's what I once learnt). In 386bsd you get >that line randomly: sometimes you gte it and sometimes not. > >Bug or normal behaviour(????) Normal behaviour. You will never see it on a PDP 11, but on fast machines like 486's and HP RISC machines, the 'ps' process can read the whole process table _before_ the 'grep' process gets _created_. It's a race-- if you try it again on a busy machine, sometimes you will see the grep and sometimes you won't. Note that since ps is earlier in the pipeline, it gets created first. Mark S.