6. Printing with Samba

Contents of this section

6.1 How do I set up basic print services?

Samba prints, in principle, by making a copy of your print data on a server
and passing a resulting file as an argument to whatever is used for
printing there. The simplest way to achieve that effect is to use a
"canned" [printers] section in a conjunction with load printers = yes
directive as described on the manpage for smb.conf.

There are a few details which have to be taken into account. If your server
print command is lpr then most likely you want to set printing = bsd in the
configuration file. If this is lp then printing = sysv. HP-UX and AIX have
their own hpux and respectively aix printing styles. If none of the above
applies, or does not work as expected, you have to configure your print
command, lpq command and lprm command in an explicit manner. See also the
section I am getting only an initial fragment of my printout; why? for more
ideas.

Make also sure that the path given in print services points to a world
writable directory, as Samba will copy the print data into there. Using
your print spool directories here is not a good idea, as, on a properly
configured system, this write access requirement is not satisfied.

Automatic configuration via [printers] section works only in the presence
of an /etc/printcap, or equivalent, file. Sometimes (e.g. NEXTSTEP or
Solaris) such a file does not exist. You may either provide a "dummy
printcap" (basically only printer names are needed there) or configure
print services by creating a configuration section for every printer. This
can actually be preferable, even if /etc/printcap does exist, especially if
you need finer control of how the printers are configured. For example, if
you do not want to show all your printers, or if you want to give access to
some printers only from some machines (with the help of include), or by
certain users only (valid users can be useful here).

See also load printers in the smb.conf manpage. If you prefer to show
globally as shares only some printers from your /etc/printcap file then you
may want to use auto services list instead.

6.2 How do I show printer names less daunting than lp4js?

This can be a problem when there are multiple printers on a network, in
multiple locations, and "what is what" is not clear from the names.

If you specify your print services explicitly then the matter is simple.
Add a comment in your service and it will show up in browsers. Otherwise
you may add comment strings in the /etc/printcap file. For example, if your
printer entry reads like:

  lp4js|lp12|LaserJet on the third floor by the coffee machine:\
     .....(other stuff)...

then a name with blanks in it, the third one in this case, will be taken by
Samba as a comment on the service. If such a name does not exist then
something else will be picked ( hard to tell what...).

ATTENTION! Share names, legal across various subprotocols of SMB, cannot be
longer than eight characters. If all names in your printcap entry are
longer than that then Samba will silently skip such entry and the
corresponding printer will remain hidden to your clients. This does not
apply to printer shares specified explicitely in smb.conf (you will get
complaints for names too long but they will be there if your clients can
handle them).

6.3 How do I test what I am sending to my printer?

Temporarily replace your print command with something like this:

  print command = cat %s > /tmp/print.%m.$$ ; rm -f %s

This will create a "print" file marked by the name of a sending client and
a writer process number. Now you may try to figure out if your printer will
really like it. :-)

6.4 I have a printer on a client machine. Can I print from a server?

At least for Windows and NT it is possible to find software (commercial and
not) which will make a printer connected to a client into a "regular"
network printer. It can then be configured for any Unix machine as a remote
printer.

If you do not have such software but a printer is exported by the client as
a "share" you may use smbclient with the -P option to connect to it. The
following sample shell script should get you started.
---------------------------------------------------------------------------

#!/bin/sh
# Print from Unix on a printer on SMB network.  An assumption is that
# 'printer' was posted as a passwordless "share"
#
client="myclient"   # client name here...
pshare="printer"    # and here printer share name
printfile="/tmp/smbspool.$$"

cat > $printfile
if [ -s $printfile ] ; then
  ( echo "translate" ; echo "print $printfile" ; echo "quit" ) \
  | smbclient \\\\$client\\$pshare -P -N
fi
rm -f $printfile
exit 0

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Once you have something like that running you may add to your server a new
printer, which "prints" on /dev/null, and with this script as a default
print filter for it. Details of doing that vary between different print
models, so check your docs. Subsequently you will use "normal" print
commands from your server to print on your client printer (lpr -Psmb, or
something like that), spooling and printing from stdin will work, etc. In
such settings you may want to print with a command which creates a symbolic
link to an original file (lpr -s in "bsd model"), especially for bigger
files. Otherwise you will end up, for a short time, with three copies of
your input (an original, a copy in a printer spool directory and the
"smbspool" copy to be sent on the network).

6.5 I am getting only an initial fragment of my printout; why?

Historically, print software, by default, was limiting the size of accepted
input. Usually this would be something like 1 MB, which is something like
five hundred pages of straight text and looks reasonable enough. Nowadays,
with graphic printouts (and even text is usually sent in a graphics mode as
well ) this no longer makes sense. You may change this limit by editing the
value of mx in your /etc/printcap or equivalent; :mx#0: means "no limit".
You may still want to be careful with that, however, unless you have
infinite amounts of storage and paper!

Another possibility, if your print software allows it, is to print using a
symbolic link instead of a copy into a printer spool directory. For
example, with bsd-style print software

   print command = lpr -s -r -P %p %s

will do this, and it will remove the input file, placed by Samba, once it
is done. This configuration can be to your advantage even with :mx#0: since
you avoid creating two copies (one by Samba, the other one in a spool
directory) for potentially big data files. If you have a lot of clients
printing big jobs, this may save you a lot of disk.

6.6 Why does my Postscript printer refuse to cooperate?

The output send by Windows printer drivers is only "more-or-less"
Postscript. Various Postscript interpreters try to deal with that but do
not always succeed. Samba has postscript = True which attempts to help.
Unfortunately this is not a good idea, globally, in [printers] section, if
you have printers which are capable of Postscript and some non-Postscript
printers and you are not configuring them individually, or you have
printers like some HP models which would accept both Postscript and
non-Postscript (HPGL) jobs.

A better approach is to try to configure your Windows printer drivers to
not send the initial "control-D from hell". If you look at many of the
Windows printer drivers, they send this is a default. Fortunately this may
be turned off! This will help with the most blatant standard violations,
but alas, not always. For some examples see the next question.

6.7 How do I make a NEXTSTEP server accept Windows output?

This is an example of "nearly Postscript but not quite" problems. The
trouble is that some initialization and cleanup which should be in the
document header and trailer is packed by Windows into the first and last
page comments. NeXT normally prints in reverse page order (collated), and
things do not happen at the right time, and, therefore, nothing works
properly.

Here are possible suggestions for how do deal with this:

   * In your printer "ppd" file comment out the line *DefaultOutputOrder:
     Reverse by putting `%' after `*'. It works but you will have to
     collate all your print jobs by hand (sigh...).
   * Copy "ppd" to file with a slightly different name, comment out the
     "Reverse" line like above, provide a second, non-reversing, logical
     printer on the same physical device (possibly use niload for that) and
     print Windows jobs on it. We have not tested this in a real-life
     situation, but hopefully it should work.
   * Add a filter in print command to strip as much as you dare of the
     comments. Piping through a simple

        sed '/^%%/d'

     may work. The Postscript interpreter will be not able to reverse pages
     and files will print. Check with Shon Vella, shon@novell.com, for
     details.
   * Another variant of the above; not really required, but maybe with a
     better aesthetic appeal. Create a printer with /dev/null for an output
     device and a filter like this:

        sed '/^%%/d' | lpr

     Export with Samba only this printer. (This uses a standard Unix trick
     for adding filters to printers where you otherwise cannot; like to
     remote ones).

On the other hand Eugene Mah, eugene@raddi.uah.ualberta.ca, reports that he
prints with a NEXTSTEP server by telling PCs that they print on an HP
Laserjet III with Postscript and with postscript = yes in the configuration
file. Your mileage may vary.

6.8 Can I make other Unix peripheral devices available to my clients?

Why not? On the Unix side every peripheral device, for example a tape
drive, looks like a file (possibly "special", with a limited set of valid
operations on it). If you can export it as a Samba service writable to a
client then a client may type to it (or from it) on its side. A weird
variation on backup services, and not one for the faint-of-heart.

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