Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!uflorida!haven!udel!princeton!phoenix!phoenix.princeton.edu!ron From: ron@clarity.Princeton.EDU (Ronald Beekelaar) Newsgroups: comp.lang.postscript Subject: Re: How do you count the number of pages in a postscript document? Message-ID: Date: 21 Oct 89 06:21:00 GMT References: <1955@cunixc.cc.columbia.edu> <1517@tukki.jyu.fi> <1361@scaup.cl.cam.ac.uk> <2677@hydra.gatech.EDU> Sender: news@phoenix.Princeton.EDU Organization: Cognitive Science Lab. Princeton University. Lines: 28 In-reply-to: robert@shangri-la.gatech.edu's message of 20 Oct 89 23:58:14 GMT In article <2677@hydra.gatech.EDU> robert@shangri-la.gatech.edu (Robert Viduya) writes: . > . > The determined user will be able to cheat even on this unless you . > execute both examinations of the page count in nice, clean, start of . > job, PostScript environments. This requires keeping the initial value . > external to the LaserWriter. (Or perhaps Geoff can work out for us how . > to keep it in a protected, exitserver-installed, piece of workspace . > that survives between jobs!) . > . . I've managed to do this for our publicly accessible PostScript . printers so that we can do accurate page accounting for them. . Specifically, the first time a printer is accessed after power-up, a . small job gets sent down that does an "exitserver" and then redefines . the serverloop. The new serverloop sends a message to the host after . each job with the number of pages that job used. . . robert . As long as you are able to send a "small job" to the printer to change exit- server, anybody who wants to cheat, can also do this. Or change it temporarily, so his pages won't be recorded! Or this page accounting not ment for charging of the users. Obviously in that case you don't have to be afraid for cheating. ron