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| 13 | <A HREF="LPRng-HOWTO.html#toc15">Contents</A> |
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| 14 | <HR> |
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| 15 | <H2><A NAME="accountingref"></A> <A NAME="s15">15. Accounting</A></H2> |
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| 16 | |
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| 17 | <P>The LPRng method for doing accounting is based on experiences in a |
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| 18 | Academic environment, where avoiding printing accounting procedures |
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| 19 | has long been practiced. While the LPRng procedures are not bombproof, |
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| 20 | they do provide a wide range of facilities, with various degrees |
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| 21 | of trust built into them. |
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| 22 | <H2><A NAME="ss15.1">15.1 Printer Accounting Reality Check</A> |
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| 23 | </H2> |
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| 24 | |
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| 25 | <P>The following was written |
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| 26 | by Patrick Powell |
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| 27 | <CODE><papowell@astart.com></CODE> |
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| 28 | in response to the expressions of frustration |
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| 29 | that are periodically vented in the |
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| 30 | <CODE> |
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| 31 | <A HREF="LPRng-HOWTO-1.html#maillist">lprng@lprng.org</A></CODE> |
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| 32 | mailing list. |
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| 33 | While this addresses the use of a particular set of printer filters, |
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| 34 | i.e. - the |
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| 35 | <A HREF="LPRng-HOWTO-13.html#ifhp">ifhp</A> |
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| 36 | set, |
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| 37 | the comments are appropriate to other issues. |
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| 38 | <P>In Academic institutions, avoiding printing accounting has been |
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| 39 | regarded as a challenge, an ongoing game of fat cat and poor starving |
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| 40 | mouse, between the Administration and the downtrodden, poor, over charged |
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| 41 | student. The following is a lighthearted ramble down the dark lane of |
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| 42 | printing accounting. |
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| 43 | <P>We will disregard the fact that if most students put as much effort |
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| 44 | into their studies as in finding ways to avoid accounting procedures |
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| 45 | then they would be Rhodes Scholar material, but I digress... |
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| 46 | <P>The accounting procedures put into the LPRng and the hpif filters may |
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| 47 | appear to be extraordinarily complex, but believe me, they are not. |
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| 48 | Firstly, we make the assumption that the printer has some sort of |
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| 49 | non-volatile page counter mechanism that is reliable and impervious to |
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| 50 | power on/off cycles. Without this mechanism the enterprising student |
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| 51 | ummm... user will simply turn off the printer. Software that prescans |
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| 52 | jobs for line counts and pages is notoriously unreliable, given even |
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| 53 | the most modest efforts of users to hide these procedures. The cost |
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| 54 | of running a PostScript simulator simply to do accounting has its |
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| 55 | flaws; without ensuring that the simulator has all of the interesting |
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| 56 | security loopholes closed, such as opening files, etc., it can become |
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| 57 | a trap door to hell for the system administrator. |
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| 58 | <P>Secondly, we must make the assumption that the student... uhhh... |
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| 59 | user will not be able to tinker with the page counter mechanism, i.e.- |
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| 60 | they will not be able to roll back the odometer on the printer, FOR THE |
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| 61 | DURATION OF A SINGLE JOB. I will digress and point out that a student |
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| 62 | actually did this for a challenge; it only took him a couple of weeks |
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| 63 | of study and a fully equipped microcontroller lab, and two (2) laser |
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| 64 | printers which he ruined in the experiment. HP was not amused when we |
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| 65 | sent them back under warranty, claiming that this our 'normal lab usage.' |
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| 66 | <P>Lastly, you should not mind a small amount of pilferage, or a few |
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| 67 | pages here and there being charged to the wrong account. |
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| 68 | <P><B>How Does It Work?</B> |
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| 69 | <P>The <CODE>ifhp</CODE> filter records the page |
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| 70 | counter value at the start and end of each part of a print job. Each |
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| 71 | record has the form: |
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| 72 | <BLOCKQUOTE><CODE> |
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| 73 | <PRE> |
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| 74 | start -ppagecounter -Ff -kjob -uuser -hhost -R... |
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| 75 | end -ppages -qpagecounter -Ff -kjob -uuser -hhost -R... |
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| 76 | </PRE> |
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| 77 | </CODE></BLOCKQUOTE> |
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| 78 | <P>When we use the OF filter and/or banners, we will see the |
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| 79 | individual jobs bracketed by the OF filter records: |
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| 80 | <BLOCKQUOTE><CODE> |
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| 81 | <PRE> |
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| 82 | start -p100 -Fo -kcfA100taco -uuser -hhost -R... |
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| 83 | start -p101 -Ff -kcfA100taco -uuser -hhost -R... |
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| 84 | end -p1 -q102 -Ff -kcfA100taco -uuser -hhost -R... |
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| 85 | start -p102 -Ff -kcfA100taco -uuser -hhost -R... |
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| 86 | end -p3 -q105 -Ff -kcfA100taco -uuser -hhost -R... |
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| 87 | end -p5 -q105 -Fo -kcfA100taco -uuser -hhost -R... |
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| 88 | </PRE> |
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| 89 | </CODE></BLOCKQUOTE> |
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| 90 | <P>It should be clear from the above that all we need to do is to add up |
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| 91 | the values for the -Fo (OF) filter lines and we are done. |
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| 92 | <P>Unfortunately, this is too simplistic. If for some reason the job is |
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| 93 | killed or terminates due to error conditions, the OF filter may not |
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| 94 | get to finish its work. Thus, we may see the following: |
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| 95 | <BLOCKQUOTE><CODE> |
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| 96 | <PRE> |
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| 97 | start -p100 -Fo -kcfA100taco -uuser -hhost -R... |
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| 98 | start -p101 -Ff -kcfA100taco -uuser -hhost -R... |
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| 99 | start -p110 -Fo -kcfA101taco -uuser -hhost -R... |
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| 100 | </PRE> |
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| 101 | </CODE></BLOCKQUOTE> |
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| 102 | <P>This is a clear indication that the user's job has been terminated. In |
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| 103 | this case we need to use the differences between pagecounters of the start |
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| 104 | records to do accounting. |
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| 105 | <P>There is a caveat to all of this; that is the problem of the last dead |
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| 106 | job in the list. If the last line in the accounting file is: |
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| 107 | <BLOCKQUOTE><CODE> |
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| 108 | <PRE> |
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| 109 | start -p110 -Fo -kcfA101taco -uuser -hhost -R... |
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| 110 | </PRE> |
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| 111 | </CODE></BLOCKQUOTE> |
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| 112 | |
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| 113 | is the last job finished or did it abort? |
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| 114 | <P><B>Who Used Up 2000 Pages of Paper Today?</B> |
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| 115 | <P>Now we move on to the problem of real time accounting. Due to limited |
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| 116 | budgets, etc., many institutions would like to strictly enforce limits |
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| 117 | on paper use by students. As jobs are printed their accounts should be |
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| 118 | docked for the amount of paper use. One way to do this is to have an |
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| 119 | external accounting procedure update a shared database. The <CODE>ifhp</CODE> filter |
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| 120 | has provision for a shell script to be called at the end of print job; |
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| 121 | this is done by both the OF and IF filter. Thus, we can blithely |
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| 122 | assume that there is a central database carefully getting updates |
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| 123 | from the LPRng software, probably from dozens of different printers, |
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| 124 | and updating the accounting information. |
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| 125 | <P>The first question to be asked is simple: is this worth it? |
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| 126 | Perhaps doing accounting as a batch job once an hour/four times |
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| 127 | a day/once a day is cheaper than building an running such a database. |
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| 128 | If it costs $5K/year for the database software, you might just consider |
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| 129 | ignoring the 10,000 pages that get lost in the shuffle and use |
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| 130 | a simple set of awk/sed/perl scripts to update a database once |
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| 131 | an hour. |
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| 132 | <P><B>BAD JOBS - Who Do We Bill?</B> |
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| 133 | <P>We inevitably run into an interesting question: |
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| 134 | what happens if a job does not complete correctly? |
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| 135 | <P>If you use the completion of the OF filter as a success status, I have |
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| 136 | to point out that many students... ummm... users soon find ways to send |
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| 137 | jobs to the printer that will cause it to lock up after their output |
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| 138 | has been printed. These jobs require power cycling of the printer and |
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| 139 | restarting the filter; a bit extreme, perhaps, but it has happened. |
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| 140 | <P>I suggest that you simply adopt a 'bill to last user of record' |
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| 141 | attitude, using the pagecount information as follows: |
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| 142 | <BLOCKQUOTE><CODE> |
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| 143 | <PRE> |
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| 144 | start OF -- starting point for THIS job |
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| 145 | start IF -- nice information, but not useful |
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| 146 | start IF -- |
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| 147 | end OF -- ending point for this job - can record information |
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| 148 | start OF -- |
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| 149 | if no end OF for previous job, then treat as end OF and |
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| 150 | update accounting. |
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| 151 | </PRE> |
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| 152 | </CODE></BLOCKQUOTE> |
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| 153 | <P>Now somebody is sure to complain that they got charged for a bunch of |
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| 154 | pages that they did not use. This is inevitable; always carry a |
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| 155 | can of oil for the squeaky wheels. I might make the observation that |
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| 156 | once is accident, twice is coincidence, but three times is malice; |
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| 157 | be wary of the constant complainer and check out not only him or her but |
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| 158 | also their co-workers. |
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| 159 | <P><B>How Do We Update the Database?</B> |
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| 160 | <P>I suggest that database update be done as follows: |
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| 161 | <P>You maintain a 'last page reported' counter for each printer in the |
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| 162 | database. When a successful job reports in, check to see that<BR> |
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| 163 | pagecount + joblength == newpagecount; |
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| 164 | <P>If this is not the case, then you have had a some unsuccessful jobs. |
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| 165 | In this case I strongly recommend that you have a means to request the |
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| 166 | accounting reporting program to go back through the accounting file and |
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| 167 | find the last report for the page counter value and try to backtrack |
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| 168 | through the accounting files. The accounting file is one of the first |
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| 169 | things to be attacked by students... Ummm... users. It should NOT be |
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| 170 | kept on an NFS exported or mounted file system. It should be |
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| 171 | carefully pruned and copied, perhaps on an hourly basis. |
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| 172 | <P>Now some administrators have fallen in love with network based printers; |
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| 173 | do not believe ANYTHING that comes over a network connection without |
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| 174 | some form of authentication; PGP has some very nice Public Key |
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| 175 | mechanisms for handling this. This is a major weakness in using a |
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| 176 | database for keeping track of accounting - a weak authentication |
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| 177 | mechanism may lead to denial of service attacks by students flooding |
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| 178 | the database with bogus print usage reports; suddenly NOBODY can print |
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| 179 | and the administrator is driven to turning off accounting. |
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| 180 | <P>Good luck. I am never surprised when I encounter yet another wrinkle in |
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| 181 | this area. |
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| 182 | <P>Patrick ("You call me a Bean Counter? Guido, break this kid's fingers<BR> |
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| 183 | with an adding machine!") Powell |
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| 184 | <H2><A NAME="ss15.2">15.2 How HP Printers Implement Page Counters</A> |
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| 185 | </H2> |
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| 186 | |
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| 187 | <P>The following is from |
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| 188 | <A HREF="http://www.hp.com/cposupport/printers/support_doc/bpl02119.html">http://www.hp.com/cposupport/printers/support_doc/bpl02119.html</A><P><B>HP LaserJet Printer Family - Page Count</B> |
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| 189 | <P>Description Of The Page Count Feature On HP LaserJet 4 Family |
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| 190 | Printers |
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| 191 | <P>All HP LaserJet 4/5/6 family printers have a page count feature |
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| 192 | built into the firmware. However, this feature works differently |
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| 193 | depending on which HP LaserJet printer is being used. The following |
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| 194 | is a description of how the page count feature works for each |
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| 195 | printer within the HP LaserJet 4/5/6 printer families. |
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| 196 | <BLOCKQUOTE><CODE> |
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| 197 | <PRE> |
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| 198 | HP LaserJet 4/4M printers |
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| 199 | HP LaserJet 4 Plus/4M Plus printers |
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| 200 | HP LaserJet 4P/4MP printers |
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| 201 | HP LaserJet 4Si/4Si MX printers |
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| 202 | HP LaserJet 4ML printers |
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| 203 | HP LaserJet 5P/5MP printers |
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| 204 | HP LaserJet 6P/6MP printers |
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| 205 | </PRE> |
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| 206 | </CODE></BLOCKQUOTE> |
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| 207 | <P>All of the above printers use the same method for keeping track of |
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| 208 | the number of copies. There are really two different page count |
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| 209 | values: Primary and Secondary values. Every time a page is printed, |
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| 210 | whether it is an internal job (such as a self-test) or a standard |
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| 211 | print job, the Secondary page count increases by one. This value |
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| 212 | is stored in standard RAM. Once the Secondary page count value |
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| 213 | reaches 10, the Primary page count will increase by 10. The Primary |
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| 214 | page count value is stored in a type of memory called NVRAM |
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| 215 | (Non-Volatile RAM). This is important, since NVRAM is not cleared |
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| 216 | when the printer is powered off. Standard RAM, on the other hand, |
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| 217 | is cleared when the printer is turned off or reset. Thus, the |
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| 218 | Primary page count only increases in increments of 10. |
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| 219 | <P>Example |
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| 220 | <P>You have a brand new HP LaserJet 6P printer and you print a self-test |
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| 221 | page. When you look on the test page for the Page Count value, you |
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| 222 | will see that it says 1. Next, you decide to print a two page letter |
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| 223 | and, after that, another self-test. The page count value now says |
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| 224 | 4. Internally, the printers Secondary page count (stored in RAM) |
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| 225 | has the value of 4 while the Primary page count (stored in NVRAM) |
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| 226 | still has the value of 0. Now, you turn the printer off, then back |
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| 227 | on, and print another self-test. The page count value again says |
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| 228 | 1 since the previous value of 4, stored in RAM, was cleared when |
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| 229 | the printer was powered off. Finally, print a ten page document |
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| 230 | and then turn the printer off. Upon turning the printer back on |
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| 231 | and printing out another self test, you see that the page count |
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| 232 | value is 11. Internally, the Secondary page count value is back |
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| 233 | at 1 while the Primary page count value (stored in NVRAM) is 10. |
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| 234 | Added together, you end up with the resulting value seen on the |
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| 235 | self-test page. |
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| 236 | <P>HP LaserJet 4L/5L/6L Printers |
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| 237 | <P>The reason that the page count method for the HP LaserJet 4L/5L/6L |
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| 238 | printers differ from that of the other printers is that the HP |
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| 239 | LaserJet 4L/5L/6L printers do not have any NVRAM available. Thus, |
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| 240 | no way exists for the printer to retain a page count value once |
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| 241 | the printer is powered off. The HP LaserJet 4L/5L/6L printers have |
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| 242 | only a single page count value that increases in increments of one |
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| 243 | until the printer is powered off. At that point, the page count |
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| 244 | value is reset and begins from 0 once again. |
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| 245 | <P> |
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| 246 | <H2><A NAME="accountingserver"></A> <A NAME="ss15.3">15.3 Accounting Printcap Options</A> |
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| 247 | </H2> |
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| 248 | |
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| 249 | <P>The accounting facilities are controlled and enabled by the following |
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| 250 | entries in the printcap file. The default value is indicated. |
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| 251 | <P> |
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| 252 | <CENTER><TABLE BORDER><TR><TD> |
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| 253 | <BR> |
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| 254 | Tag</TD><TD>Default Value</TD><TD>Purpose</TD></TR><TR><TD> |
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| 255 | af</TD><TD>NULL</TD><TD>accounting file name</TD></TR><TR><TD> |
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| 256 | as</TD><TD>"jobstart $H $n $P $k $b $t"</TD><TD>accounting info for job start</TD></TR><TR><TD> |
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| 257 | ae</TD><TD>"jobend $H $n $P $k $b $t"</TD><TD>accounting info for job end</TD></TR><TR><TD> |
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| 258 | accounting_server</TD><TD>NULL</TD></TR><TR><TD> |
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| 259 | achk</TD><TD>FALSE</TD></TR><TR><TD> |
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| 260 | la</TD><TD>TRUE</TD><TD>do accounting for 'local' printer</TD></TR><TR><TD> |
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| 261 | ar</TD><TD>FALSE</TD><TD>do accounting for 'remote' transfers</TD></TR><TR><TD> |
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| 262 | |
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| 263 | </TD></TR></TABLE></CENTER> |
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| 264 | <P> |
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| 265 | <H2><A NAME="ss15.4">15.4 Accounting File</A> |
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| 266 | </H2> |
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| 267 | |
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| 268 | <P>The most common method of accounting is to record the start and end |
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| 269 | times of a job and its size to the accounting file. A typical entry |
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| 270 | for the printcap defaults are shown below. |
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| 271 | <BLOCKQUOTE><CODE> |
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| 272 | <PRE> |
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| 273 | jobstart '-Htaco.astart.com' '-nroot' '-Pps' '-kcfA938taco.astart.com' \ |
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| 274 | '-b1093' '-tNov 5 19:39:59' |
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| 275 | start '-p12942' '-kcfA938taco.astart.com' '-nroot' '-htaco.astart.com' '-Pps' \ |
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| 276 | '-c0' '-Fo' '-tSun Nov 5 19:39:25 1995' |
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| 277 | start '-p12944' '-kcfA938taco.astart.com' '-nroot' '-htaco.astart.com' '-Pps' \ |
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| 278 | '-c0' '-Ff' '-tSun Nov 5 19:39:27 1995' |
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| 279 | end '-p12944' '-kcfA938taco.astart.com' '-nroot' '-htaco.astart.com' '-Pps' \ |
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| 280 | '-b3' '-c0' '-Ff' '-tSun Nov 5 19:39:58 1995' |
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| 281 | end '-p12942' '-kcfA938taco.astart.com' '-nroot' '-htaco.astart.com' '-Pps' \ |
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| 282 | '-b2' '-c0' '-Fo' '-tSun Nov 5 19:39:59 1995' |
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| 283 | jobend '-Htaco.astart.com' '-nroot' '-Pps' '-kcfA938taco.astart.com' \ |
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| 284 | '-b1093' '-tNov 5 19:39:59' |
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| 285 | </PRE> |
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| 286 | </CODE></BLOCKQUOTE> |
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| 287 | <P>The <CODE>jobstart</CODE> and <CODE>jobend</CODE> lines are added by the LPD server, as |
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| 288 | specified by the <CODE>as</CODE> and <CODE>ae</CODE> printcap options; |
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| 289 | the -b (byte count) indicates the numbers of bytes in the job. |
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| 290 | <P>The <CODE>start</CODE> and <CODE>end</CODE> |
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| 291 | lines are produced by the filters; |
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| 292 | the of filter has an -Fo, and the if filter a -Ff entry. |
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| 293 | The filters in the LPRng distribution produce the |
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| 294 | indicated output format by default. |
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| 295 | The -p value is the current value of a page counter device (if any), |
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| 296 | and the -b value indicates the total number of pages used. |
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| 297 | <P>It should be clear that a simple AWK or Perl script will be able to |
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| 298 | process an accounting file and update accounting information for |
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| 299 | accounting purposes; the usual problems with truncation, time stamps, |
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| 300 | etc., are left as an exercise for the system administrator. |
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| 301 | However, |
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| 302 | for those who are exercise challenged, |
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| 303 | the LPRng distribution |
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| 304 | <CODE>.../LPRng/UTILS/accounting.pl</CODE> |
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| 305 | file is a template that can be used to process the accounting information. |
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| 306 | The printcap for using this file should resemble: |
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| 307 | <BLOCKQUOTE><CODE> |
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| 308 | <PRE> |
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| 309 | pr: |
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| 310 | :as=|/.../accounting.pl START |
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| 311 | :ae=|/.../accounting.pl END |
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| 312 | :if=/.../ifhp |
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| 313 | :of=/.../ofhp |
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| 314 | # set this to the printing device |
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| 315 | :lp=prdevice |
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| 316 | :sd=/.../%P |
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| 317 | </PRE> |
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| 318 | </CODE></BLOCKQUOTE> |
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| 319 | <P>Note that the accounting file must exist and will not be created by the |
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| 320 | <CODE>lpd</CODE> server. |
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| 321 | The accounting file should be periodically truncated. |
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| 322 | <H2><A NAME="ss15.5">15.5 Accounting Using an Accounting Server</A> |
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| 323 | </H2> |
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| 324 | |
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| 325 | <P>To accommodate even more aggressive and centralized accounting, |
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| 326 | a method to make a connection to a print server and send information |
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| 327 | to the server has been provided as well. |
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| 328 | If <CODE>achk</CODE> option is set, |
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| 329 | it is assumed that the <CODE>af</CODE> entry specifies a connection to |
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| 330 | server on a remote host. |
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| 331 | The <CODE>lpd</CODE> server will send the <CODE>as</CODE> string to the server, |
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| 332 | and then wait for a single line of text from the remote server. |
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| 333 | If the first word on the return line is |
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| 334 | <CODE>accept</CODE> or <CODE>hold</CODE>, |
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| 335 | the job will be either accepted for printing or held. |
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| 336 | Any other value will cause the job to be deleted. |
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| 337 | <P>At the end of the job the <CODE>ae</CODE> string will be sent to the server. |
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| 338 | No response is expected. Example: |
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| 339 | <P> |
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| 340 | <BLOCKQUOTE><CODE> |
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| 341 | <PRE> |
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| 342 | :af=accounting.site.com%2300,tcp |
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| 343 | :achk |
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| 344 | :as=starting |
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| 345 | :ae=ending |
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| 346 | </PRE> |
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| 347 | </CODE></BLOCKQUOTE> |
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| 348 | <P>The port that the connection originates from will be in the range |
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| 349 | set by the configuration or printcap |
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| 350 | <CODE> |
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| 351 | <A HREF="LPRng-HOWTO-18.html#originateport">originate_port</A></CODE> |
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| 352 | option. |
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| 353 | <H2><A NAME="ss15.6">15.6 Using Filters For Accounting</A> |
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| 354 | </H2> |
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| 355 | |
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| 356 | <P>Some sites have expressed interest in using a central accounting |
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| 357 | mechanism to check that users have permissions. This can be done by |
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| 358 | using the an alternative form of the as (accounting start) and ae |
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| 359 | (accounting end) printcap tags. If the as and ae are filter |
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| 360 | specifications, then a filter is invoked. If the as (accounting |
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| 361 | start) filter returns a non-zero exit status, then its value |
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| 362 | is used to handle the job as indicated by |
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| 363 | the |
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| 364 | <A HREF="LPRng-HOWTO-12.html#termination">Abnormal Termination</A> |
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| 365 | codes for filters. |
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| 366 | At the end of the job the :ae: filter will be invoked in a similar manner, |
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| 367 | but its exit status is ignored. |
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| 368 | <P>When using an accounting filter, |
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| 369 | the STDIN is attached (read/write) to the accounting file or remote host |
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| 370 | specified by the <CODE>af</CODE> printcap option, |
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| 371 | STDOUT to the output device, |
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| 372 | and STDERR to the status file. |
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| 373 | The filter program would be invoked with the default filter options. |
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| 374 | <P>For example, here is a sample entry to check and update accounting |
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| 375 | <BLOCKQUOTE><CODE> |
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| 376 | <PRE> |
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| 377 | printer |
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| 378 | :as=|/usr/local/libexec/filters/accounting.pl start |
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| 379 | :ae=|/usr/local/libexec/filters/accounting.pl end |
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| 380 | </PRE> |
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| 381 | </CODE></BLOCKQUOTE> |
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| 382 | <H2><A NAME="ss15.7">15.7 Accounting Utility accounting.pl</A> |
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| 383 | </H2> |
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| 384 | |
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| 385 | <P>In order to provide a framework for doing using the outlined accounting |
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| 386 | methods, the LPRng distribution |
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| 387 | <CODE>UTILS</CODE> directory has a <CODE>accounting.pl</CODE> script. |
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| 388 | This script does the following. |
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| 389 | <OL> |
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| 390 | <LI>It is assumed that the accounting filter is invoked with the |
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| 391 | following printcap entry. |
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| 392 | The start and end is used by the filter to determine at which point in |
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| 393 | the accounting process it is invoked. |
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| 394 | <BLOCKQUOTE><CODE> |
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| 395 | <PRE> |
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| 396 | printer |
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| 397 | :as=|/usr/local/libexec/filters/accounting.pl start |
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| 398 | :ae=|/usr/local/libexec/filters/accounting.pl end |
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| 399 | </PRE> |
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| 400 | </CODE></BLOCKQUOTE> |
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| 401 | </LI> |
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| 402 | <LI>It maintains the accounting file as a set of entries in the following format: |
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| 403 | <BLOCKQUOTE><CODE> |
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| 404 | <PRE> |
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| 405 | START [job identification] |
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| 406 | start -pnn ... |
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| 407 | ... |
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| 408 | end -pnn+pagecount ... |
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| 409 | END -ppagecount [job identification] |
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| 410 | </PRE> |
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| 411 | </CODE></BLOCKQUOTE> |
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| 412 | </LI> |
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| 413 | <LI>Each time the filter is invoked with the <CODE>start</CODE> |
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| 414 | tags, |
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| 415 | it will add a <CODE>START</CODE> record to the end of the accounting file.</LI> |
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| 416 | <LI>When it is invoked with the <CODE>end</CODE> option, |
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| 417 | it will update the accounting file and add an <CODE>END</CODE> entry.</LI> |
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| 418 | <LI>It will handle aborted jobs by looking for jobs with have a <CODE>START</CODE> |
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| 419 | entry and a following <CODE>start</CODE> line and assuming that they |
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| 420 | progressed to the point of starting print operations, |
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| 421 | i.e. - the printer page counter was accessed and reported. |
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| 422 | It will then look for the next <CODE>START</CODE> entry with a |
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| 423 | following <CODE>start</CODE> line, |
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| 424 | and assume that the pages between the two points were used by the |
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| 425 | aborted job.</LI> |
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| 426 | </OL> |
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| 427 | <P>Administrators can use this script as a starting point for more advanced |
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| 428 | accounting. |
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| 429 | For example, |
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| 430 | rather than just recording the information, |
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| 431 | at the job start the script can query either a local database |
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| 432 | or a remote server to see if the user has permissions to access the printer. |
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| 433 | At the end of the job or when an <CODE>END</CODE> line is written to the |
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| 434 | accounting file, |
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| 435 | the local database or remote accounting server can be updated. |
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| 436 | <HR> |
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| 437 | <A HREF="LPRng-HOWTO-16.html">Next</A> |
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| 438 | <A HREF="LPRng-HOWTO-14.html">Previous</A> |
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| 439 | <A HREF="LPRng-HOWTO.html#toc15">Contents</A> |
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| 440 | </BODY> |
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| 441 | </HTML> |
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