Chapter 10. Printing

BSD printers

TIP

If you are using the version of Samba installed from an RPM file as on Red Hat Linux, you might be able to skip these directions and use the printconf tool, which has support for SMB printers. Unfortunately, this tool might not work correctly if you have installed Samba from the Samba source distribution.

lp|maya-hp932c:\
    :cm=HP 932C on maya:\
    :sd=/var/spool/lpd/maya:\
    :af=/var/spool/lpd/maya/acct:\
    :if=/usr/local/samba/bin/smbprint:\
    :mx=0:\
    :lp=/dev/null:

The first line creates names for the printer. We are calling it both maya-hp932c, to describe its location on the network and the type of printer, and lp so that programs will use it as the default printer. The rest of the lines specify keywords and values. The cm keyword allows us to assign a comment string to the printer. The sd and af keywords assign the printer's spool directory and accounting files, respectively. The if keyword assigns the print filter. We are using the smbprint command to send the output to the shared SMB printer. The mx keyword is set to zero to allow any size file to be printed, and lp is set to /dev/null to discard error messages.

You can follow our model to create an entry for your own printer. If you want to go beyond the capabilities we used, refer to your system's printcap(5) manual page for a complete listing of keywords.

Go to your Samba source distribution's root directory, and install the smbprint program like this:

# cp examples/printing/smbprint /usr/local/samba/bin

We next create the printer's spool directory:

# cd /var/spool/lpd
# mkdir maya
# chown lp:lp maya
# chmod 700 maya

The smbprint program looks for a file named .config in the printer's spool directory, which contains information on how to connect to the printer share. We create this file and then fill in the required information:

# cd maya
# >.config
# chown lp:lp .config
# chmod 600 .config

Use your preferred text editor to edit the .config file, and enter three lines, like this:

server=maya
service=hp
password=""

This is for our shared printer having a UNC of \\maya\hp. When we created the printer share, we did not give it a password, so we use a null password here. If your printer share is on a Windows NT/2000/XP system, use your domain password.

Finally, restart the printer daemon:

# /etc/rc.d/init.d/lpd restart

You can now try printing something. Run the following command:

$ lpr textfile

System V printers

1. Change the server, service, and password parameters in the script to match the NetBIOS computer name, its shared printer service, and its password, respectively. For example, the following entries would be correct for the service in the previous example:

   server = maya
   service = hp
   password = ""

2. Run the following commands, which create a reference for the new printer (which we are naming hp_printer) in the printer capabilities file:

   # lpadmin -p hp_printer -v /dev/null -i./smbprint.sysv
   # enable hp_printer
   # accept hp_printer

After you've done that, restart the Samba daemons and try printing to hp_printer using any standard Unix program.

CUPS printers

To enable printing to remote SMB printers using CUPS, create a symbolic link named smb in the CUPS backend directory pointing to smbspool. Depending on installation options, these could be in a number of places in the directory hierarchy, so be sure to check your system. Using a common default installation, the command would look like this:

# ln -s /usr/local/samba/bin/smbspool /usr/lib/cups/backend/smb

Issue a HUP signal to the CUPS daemon, cupsd, and check for the existence of SMB support with the lpinfo -v command. Its output should now include a line that says network smb.

To add a printer, use the CUPS web interface, accessible on the local system at http://localhost:631/, or use the lpadmin command:

# lpadmin -p hp932c -E -v smb://maya/hp932c -D "HP 932C on maya"

This creates and enables the new print spool called hp932c. The -v argument specifies the printer device, which in this case is accessed over the network using an SMB URI. If the printer is not guest-accessible, you'll need to provide a username and password in the URI. The full format is as follows:

smb://[username[:password]@][workgroup/]server/printshare

Once you have the printer set up, it's time to test it out. CUPS understands both BSD-style and System V-style printing commands, so you can use whichever is more comfortable. Using the BSD lpr command, try something like:

$ lpr -P hp932c textfile

printing

Table 10-3. Printing system types

The value for this option must be one of these seven selections. For example:

printing = SYSV

The default value of this option is system-dependent and is configured when Samba is first compiled. For most systems, the configure script automatically detects the printing system to be used and configures it properly in the Samba makefile. However, if your system is a PLP, LPRNG, or QNX printing system, you need to specify this explicitly in the makefile or the printing share.

The most common system types are BSD, SYSV, and CUPS. Each printer on a BSD Unix server is described in the printer capabilities file—normally /etc/printcap. See the section on the printcap file parameter for more information on this topic.

printable

[printer1]
    printable = yes

printer

[deskjet]
    printer = hpdkjet1

lpq cache time

[deskjet]
    lpq cache time = 30

postscript

[deskjet]
    postscript = yes

load printers

print command, lpq command, lprm command,lppause command, lpresume command

These options tell Samba which Unix commands control and send data to the printer. The Unix commands involved are: lpr (send to Line PRinter), lpq (List Printer Queue), lprm (Line Printer ReMove), and optionally lppause and lpresume. Samba provides an option named after each command, in case you need to override any of the system defaults. For example, consider the following:

lpq command = /usr/ucb/lpq %p

This would set lpq command to use /usr/ucb/lpq. Similarly:

lprm command = /usr/local/bin/lprm -P%p %j

would set the Samba printer remove command to /usr/local/bin/lprm and provide it the print job number using the %j variable.

Table 10-4. Default commands for various printing options

It is usually unnecessary to reset these options in Samba, with the possible exception of the print command. This option might need to be set explicitly if your printing system doesn't have a -r (remove after printing) option on the printing command. For example:

print command = /usr/local/lpr -P%p %s; /bin/rm %s

With a bit of judicious programming, these smb.conf options can also be used for debugging:

print command = cat %s >>/tmp/printlog; lpr -r -P%p %s

Using the previous configuration, it is possible to verify that files are actually being delivered to the Samba server. If they are, their contents will show up in the file /tmp/printlog.

After BSD, the next most popular kind of printing system is SYSV (or System V) printing, plus some SYSV variants for IBM's AIX and Hewlett-Packard's HP-UX. These systems do not have an /etc/printcap file. Instead, the printcap file option can be set to an appropriate lpstat command for the system. This tells Samba to get a list of printers from the lpstat command. Alternatively, you can set the global configuration option printcap name to the name of a dummy printcap file you provide. In the latter case, the file must contain a series of lines such as:

lp|print1|My Printer 1
print2|My Printer 2
print3|My Printer 3

Each line names a printer followed by aliases for it. In this example, the first printer is called lp, print1, or My Printer 1, whichever the user prefers to use. The first name is used in place of %p in any command Samba executes for that printer.

Two additional printer types are also supported by Samba: LPRNG (LPR New Generation) and PLP (Public Line Printer). These are public domain and open source printing systems and are used by many sites to overcome problems with vendor-supplied software. Samba also supports the printing systems of the SOFTQ and QNX real-time operating systems.

printcap name

[deskjet]
    printcap name = /usr/local/samba/lib/printcap

The CUPS printing system uses its own method of determining printer capabilities, rather than the standard printcap file. In this case, set printcap name as follows:

[global]
    printing = cups
    printcap name = cups

min print space

[deskjet]
    min print space = 4000

queuepause command

This configuration option specifies a command that tells Samba how to pause an entire print queue, as opposed to a single job on the queue. The default value depends on the printing type chosen. You should not need to alter this option.

queueresume command