7.2.3.1 printing

The printing configuration option tells Samba a little about your Unix printing system, in this case which printing parser to use. With Unix, there are several different families of commands to control printing and print statusing. Samba supports seven different types, as shown in Table 7.3.

The value for this optio.n will be one of these seven options. 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 will automatically detect the printing system to be used and configure it properly in the Samba makefile. However, if your system is a PLP, LPRNG, or QNX printing system, you will need to explicitly specify this in the makefile or the printing share.

The most common system types are BSD and SYSV. Each of the printers on a BSD Unix server are described in the printer capabilities file - normally /etc/printcap.

Setting the printing configuration option automatically sets at least three other printing options for the service in question: print command, lpq command, and lprm command. If you are running Samba on a system that doesn't support any of these printing styles, simply set the commands for each of these manually.

7.2.3.2 printable

The printable option must be set to yes in order to flag a share as a printing service. If this option is not set, the share will be treated as a disk share instead. You can set the option as follows:

[printer1]
	printable = yes

7.2.3.3 printer

The option, sometimes called printer name, specifies the name of the printer on the server to which the share points. This option has no default and should be set explicitly in the configuration file, even though Unix systems themselves often recognize a default name such as lp for a printer. For example:

[deskjet]
	printer = hpdkjet1

7.2.3.4 printer driver

The printer driver option sets the string that Samba uses to tell Windows what the printer is. If this option is set correctly, the Windows Printer Wizard will already know what the printer is, making installation easier for end users by giving them one less dialog to worry about. The string given should match the string that shows up in the Printer Wizard, as shown in Figure 7.9. For example, an Apple LaserWriter typically uses Apple LaserWriter; a Hewlett Packard Deskjet 560C uses HP DeskJet 560C Printer.

Figure 7.9: The Add Printer Wizard dialog box in Windows 98

Automatically configuring printer drivers with Samba is explained in greater detail in the section Section 7.1.7, Automatically Setting Up Printer Drivers," earlier in this chapter.

7.2.3.5 printer driver file

This global option gives the location of the Windows 95/98 printer driver definition file, which is needed to give printer drivers to clients using a Samba printer. The default value of this option is /usr/local/samba/lib/printers.def. You can override this default as shown below:

[deskjet]
	printer driver file = /var/printers/printers.def

This option is explained in greater detail in the section Section 7.1.7," earlier in this chapter.

7.2.3.6 printer driver location

This option specifies a specific share that contains Windows 95 and 98 printer driver and definition files. There is no default parameter for this value. You can specify the location as a network pathname. A frequent approach is to use a share on your own machine, as shown here:

[deskjet]
	printer driver location = \\%L\PRINTER$

This option is also explained in greater detail in the section Section 7.1.7," earlier in this chapter.

7.2.3.7 lpq cache time

The global lpq cache time option allows you to set the number of seconds that Samba will remember the current printer status. After this time elapses, Samba will issue an lpq command (or whatever command you specify with the lpq command option) to get a more up-to-date status. This defaults to 10 seconds, but can be increased if your lpq command takes an unusually long time to run or you have lots of clients. The following example resets the time to 30 seconds:

[deskjet]
	lpq cache time = 30

7.2.3.8 postscript

The postscript option forces the printer to treat all data sent to it as Postscript. It does this by prepending the characters %! at the beginning of the first line of each job. It is normally used with PCs that insert a ^D (control-D or "end-of-file mark) in front of the first line of a PostScript file. It will not, obviously, turn a non-PostScript printer into a PostScript one. The default value of this options is no. You can override it as follows:

[deskjet]
	postscript = yes

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

These options tell Samba which Unix commands used to 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 of these commands, in case you need to override any of the system defaults. For example, consider:

lpq command = /usr/ucb/lpq %p

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

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

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

The default values for each of these options are dependent on the value of the printing option. Table 7.4 shows the default commands for each of the printing options. The most popular printing system is BSD.

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

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

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

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

For example, this configuration can verify that files are actually being delivered to the Samba server. If they are, their contents will show up in the /tmp/printlog file.

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 system 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, and provides 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 will be 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. In addition, the SOFTQ and QNX realtime operating systems are supported by Samba.

7.2.3.10 load printers

The load printers option tells Samba to create shares for all known printer names and load those shares into the browse list. Samba will create and list a printer share for each printer name in /etc/printcap (or system equivalent). For example, if your printcap file looks like this:[2]

[2] We have placed annotated comments off to the side in case you've never dealt with this file before.

lp:\
  :sd=/var/spool/lpd/lp:\            # spool directory
  :mx#0:\                            # maximum file size (none)
  :sh:\                              # surpress burst header (no)
  :lp=/dev/lp1:\                     # device name for output
  :if=/var/spool/lpd/lp/filter:      # text filter

laser:\
  :sd=/var/spool/lpd/laser:\         # spool directory
  :mx#0:\                            # maximum file size (none)
  :sh:\                              # surpress burst header (no)
  :lp=/dev/laser:\                   # device name for output
  :if=/var/spool/lpd/lp/filter:      # text filter

and you specify:

load printers = yes

the shares [lp] and [laser] will automatically be created as valid print shares when Samba is started. Both shares will borrow the configuration options specified in the [printers] section to configure themselves, and will be available in the browse list for the Samba server.

7.2.3.11 printcap name

If the printcap name option (also called printcap) appears in a printing share, Samba will use the file specified as the system printer capabilities file. This is normally /etc/printcap. However, you can reset it to a file consisting of only the printers you want to share over the network. The value must be a fully-qualified filename of a printer capabilities file on the server:

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

7.2.3.12 min print space

The min print space option sets the amount of spool space that must be available on the disk before printing is allowed. Setting it to zero (the default) turns the check off; setting it to any other number sets the amount of free space in kilobytes required. This option helps avoid having print jobs fill up the remaining disk space on the server, which may cause other processes to fail:

[deskjet]
	min print space = 4000

7.2.3.13 queuepause command

This configuration option specifies a command that tells Samba how to pause a print queue entirely, 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.

7.2.3.14 queueresume command

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