root / tea4cups / trunk / README @ 629

# $Id$

Tea4CUPS : Tee for CUPS

(c) 2005 Jerome Alet <alet@librelogiciel.com>
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2 of the License, or
(at your option) any later version.

This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License for more details.

You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307, USA.

=============================================================================

Tea4CUPS is the equivalent of the *nix command 'tee', but as a CUPS
backend.

Tea4CUPS behaves just like any other CUPS backend, but allows you to
transparently send print jobs' datas to any number of outputs : other
CUPS backends, files or pipes.

This for example allows you to output the same print job on several
printers at the same time, which is not possible with CUPS.

Another possibility would be for example to send the same document to 
a printer, a PDF generator, a Fax, and as an attachment to an email
message, all of this by printing it a single time.

Tea4CUPS provides three ways to launch commands :

        - prehooks : these are guaranteed to be launched before the 
                     print job is sent to the real printer.
                     Any prehook which exits -1 can cancel the 
                     print job.
                     
        - tees : these are launched at the same time the job is being             
                 sent to the real printer, unless the job was 
                 previously cancelled by a prehook.
                 
        - posthooks : these are guaranteed to be launched after the
                      print job has been sent to the real printer,
                      unless the job was previously cancelled by a
                      prehook.
                 
To help your own commands, Tea4CUPS makes available as part of the
environment several variables which can be used from the
commands you use :

        TEAPRINTERNAME : The print queue name.
        TEADIRECTORY : Tea4CUPS output directory.
        TEADATAFILE : Full name of Tea4CUPS work file (in $TEADIRECTORY).
        TEAJOBSIZE : Job's size in bytes.
        TEAMD5SUM : MD5 sum of the job's datas.
        TEACLIENTHOST : Client's hostname or IP address.
        TEAJOBID : Job's Id.
        TEAUSERNAME : Name of the user who launched the print job.
        TEATITLE : Job's title.
        TEACOPIES : Number of copies requested.
        TEAOPTIONS : Options of the print job.
        TEAINPUTFILE : Print job's data file or empty when job read from stdin.
        TEABILLING : Job's billing code (lp -o job-billing=SomeCode file.ps)
        TEACONTROLFILE : Job's IPP message file (usually /var/spool/cups/c?????)
        TEASTATUS : Original CUPS backend's exit code : ONLY AVAILABLE FROM 
                    posthooks, obviously.
        
In the case you want to use both Tea4CUPS and PyKota, you MUST install 
PyKota v1.22alpha2 or higher to avoid a race condition.

NB : Tea4CUPS requires a version of Python >= 2.1

=============================================================================

Installation :
--------------

  0 - Download Tea4CUPS from :
  
        http://www.librelogiciel.com/software/Tea4CUPS/action_Presentation
        
      and extract it :  
      
        $ tar -zxf tea4cups-x.yy.tar.gz
        
        where x.yy is Tea4CUPS' version number.
        
  1 - Copy the 'tea4cups' command into CUPS' backend directory, 
      for example :
      
        $ cp tea4cups /usr/lib/cups/backend
        
  2 - Restart CUPS in order for this new backend to be detected.        
  
  3 - Either from CUPS' web interface, add new printers with 
      'Tea4CUPS managed' in front of the device's name.
          
      Or by directly modifying CUPS' printers.conf file, prepend    
      each DeviceURI value with 'tea4cups://', and restart CUPS.
      
  4 - Copy tea4cups.conf into CUPS' configuration directory (where    
      cupsd.conf resides) :
      
        $ cp tea4cups.conf /etc/cups/
        
  5 - Modify tea4cups.conf to suit your needs. Several examples      
      are included.
      
  6 - There's no 6 !    
  
=============================================================================

Troubleshooting : 
-----------------

  1 - Set "LogLevel debug2" in CUPS' cupsd.conf
  
  2 - Restart CUPS.
  
  3 - Set "debug: yes" in the [global] section of tea4cups.conf
  
  4 - Print something on a print queue managed
      by Tea4CUPS.
      
  5 - Look at CUPS' error_log file for diagnostic and error messages.
  
=============================================================================

CUPS (Common UNIX(r) Printing System) is trademark property of Easy Software 
Products.

You can download CUPS from :

        http://www.cups.org

=============================================================================
    
Please e-mail bugs to : alet@librelogiciel.com (Jerome Alet)