consult@physc1.byu.edu (11/09/89)
I am looking for a (simple?) algorithm to count pages in a postscript file. I know almost nothing about postscript, so I am soliciting your help here. For years we have been using a modified lpr program on our Unix systems that counts the number of pages being printed and charges the user a set rate for each page. Our problem now is that users have access to laser printers over the net and if they try to print postscript files they are usually way overcharged, as there can be many more than 66 lines per page with all the font and graphics information in a postscript file. What I would like to do is first detect if the file being printed is postscript (I believe it must start with '%!', right?) and if it is use the new formula for calculating the number of pages being printed. Thanks for your help. Cary Jamison BYU CS Dept. Systems Programmer cary@cs.byu.edu
roy@phri.UUCP (Roy Smith) (11/10/89)
Unfortunately, the short answer is "you can't". PostScript is a
real programming language with loops and functions. One could, if they
wanted, write the PS version of "for = 1 to 1000000, print 'hello'" and
unless your printer accounting software had a full postscript interpreter
in it, there would be no way to know that this little 1-line print file
would produce thousands of pages of output.
In practice, however, most programs which produce PS output are
fairly well behaved and produce "%%Page" comments at the appropriate places
in the PS file, and don't do any looping. It would be straight-forward to
parse the file and look for those, but you would only be able to account
for usage by honest people using well-behaved programs.
--
Roy Smith, Public Health Research Institute
455 First Avenue, New York, NY 10016
{att,philabs,cmcl2,rutgers,hombre}!phri!roy -or- roy@alanine.phri.nyu.edu
"The connector is the network"perry@ccssrv.UUCP (Perry Hutchison) (11/11/89)
In article <1consult@physc1.byu.edu> consult@physc1.byu.edu writes: > I am looking for a (simple?) algorithm to count pages in a postscript file. This is becoming a frequently-asked question in this group. Trying to do this by inspection is a lot like trying to estimate the size of a C program's output by examining the source code. (PostScript is very much a programming language.) To do this reliably on the host system, you would have to write a PostScript interpreter. For accounting purposes (as opposed to setting print queue priority based on job size), an after-the-fact count may be acceptable. It has the advantages of being relatively simple to implement and also fairly secure. The LaserWriter (and presumably most other PostScript printers) have a host-readable counter which shows how many pages have ever been printed by this printer. You can read that counter before and after each job, and charge accordingly.
mongo@helios (Mongo Package) (11/12/89)
Responding to an article asking how to count how many pages were printed by a PostScript printer... In article <4108@phri.UUCP> roy@phri.UUCP (Roy Smith) writes: > > Unfortunately, the short answer is "you can't". PostScript is a >real programming language with loops and functions. One could, if they >wanted, write the PS version of "for = 1 to 1000000, print 'hello'" and >unless your printer accounting software had a full postscript interpreter >in it, there would be no way to know that this little 1-line print file >would produce thousands of pages of output. > >Roy Smith, Public Health Research Institute >"The connector is the network" Here at Lick Observatory we not only account for the number of pages printed, but also for the amount of LaserWriter cpu time necessary to do it. This is accomplished by using a home-grown printer driver which sends out the LaserWriter commands "pagecount" and "usertime" before and after each job is transmitted. It reads these back off the serial port and takes the difference at the end. We then charge the print requestor for both pages and cpu time. (Disclaimer--I personally consider accounting for cpu to be particularly abhorrent, but the UC _loves_ bureaucracy and _especially_loves_ to give people pieces of paper that say "You owe us $$$".) Steve Allen mongo@helios.ucsc.edu Internet mongo@portal BITNET ...!ucbvax!ucscc!helios!mongo UUCP