Chapter 10. Printing

If you have printers +connected to systems running Windows 95/98/Me or Windows NT/2000/XP, +the printers can also be accessed from your Unix system using tools +that are part of the Samba distribution. First, it is necessary to +create a printer share on the Windows system. Then set up the printer +on the Unix side by configuring a new printer and using a Samba +printing program as the printer's filter.

Sharing Windows Printers

Sharing printers on Windows is not unlike sharing files. In fact, it +is a little simpler. Open the Control Panel, then double-click the +Printers icon to open the Printers window. Right-click the icon for +the printer you want to share, and select Sharing.... This opens the +dialog box shown in Figure 10-5 for a Windows 98 +system, or Figure 10-6 on a Windows 2000 system. +(The dialog box appears slightly different on other Windows versions, +but functions almost identically.)

+ +

TIP
+
On Windows 95/98/Me systems, you may need to run file sharing in +share-level (rather than user-level) access control mode to access a +shared printer from Samba. To check or set this mode, go to Control +Panel, then double-click on Network, then click on the Access Control +tab. More detailed information on this can be found in Chapter 5.
+

+ +

Figure 10-5. Sharing printers on Windows 98

Figure 10-6. Sharing printers on Windows 2000

Click the "Shared as" radio button, +then click the OK button. The printer is now accessible by other +systems on the network.

Adding a Unix Printer

The Samba distribution comes with +three programs that assist with printing on shared printers. The +smbprint program works with systems that use the +BSD printing system, +smbprint.sysv +works with systems that use System V printing, and +smbspool +works with systems that use the Common Unix Printing System (CUPS). +In the following sections we show you how to install printers for +each system.

BSD printers

The +BSD printing system is used by many Unix variants, including Red Hat +Linux. With BSD printing, all the printers on the system have an +entry in the /etc/printcap file, which is the +database of printer capabilities used by the lpd +line printer daemon and other programs that assist with printing. The +Red Hat Linux implementation is a bit different in that +/etc/printcap is a machine-generated file, which +is re-created every time the lpd daemon is +restarted by the /etc/rc.d/init.d/lpd script. +Instead of editing /etc/printcap, we will add an +entry for our printer in /etc/printcap.local, +which the system automatically includes verbatim when creating +/etc/printcap.

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.
+

Here is the entry we added to our +/etc/printcap.local file to support our Hewlett-Packard +DeskJet 932C printer, which is shared by maya, a +Windows 98 system:

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

If you have everything set up correctly, the file prints on the +shared printer. If you get "stair +stepping" of text, caused by the printer not +returning to the left margin at the beginning of every line, modify +the if keyword in your printcap entry to run +smbprint with the -t +option.

System V printers

Sending print jobs from a System V Unix +system is a little easier than with the BSD system. Here, you need to +edit the smbprint.sysv script in the +examples/printing directory of the Samba +distribution and do the following:

+
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 = ""
```
+
+
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

CUPS [2] uses +a set of modules, called +backends, to send print jobs to various +destinations, such as local printers attached to parallel, serial, or +Universal Serial Bus (USB) ports, or over the network using Unix line +printer daemon (LPD) protocol, Internet Printing Protocol (IPP), +AppleTalk Printer Access Protocol (PAP), and so on. The software +package does not come with a backend for SMB; the Samba suite +includes the smbspool +utility for this purpose.

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

The lpadmin command makes changes to +/etc/cups/printers.conf and sends a HUP signal +to the cupsd daemon, resulting in the creation +of a local raw printer spool. In this example, print data is passed +in raw format to the Windows system, which has the necessary printer +drivers and printer description files to format the data +appropriately. The -D option is used to give the +printer a comment string.

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

You should now be set up to use the printer from any application on +the Unix system.

Samba Printing Options

Table 10-2 summarizes the Samba printing +options.

+ + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + +

Table 10-2. Printing configuration options

+ Option +	+ Parameters +	+ Function +	+ Default +	+ Scope +
+ `printing` +	+ `bsd`, `sysv`, +`cups`, `hpux`, +`aix`, `qnx`, +`plp`, `softq`, or +`lprng` +	+ Printing system type of the Samba host +	+ System-dependent +	+ Share +
+ `printable` `(print ok)` +	+ boolean +	+ Marks a share as a printing share +	+ `no` +	+ Share +
+ `printer` `(printer name)` +	+ string (Unix printer name) +	+ Name for the printer that is shown to clients +	+ System-dependent +	+ Share +
+ `lpq cache time` +	+ numeric (time in seconds) +	+ Amount of time in seconds that Samba will cache the printer queue +status +	+ `10` +	+ Global +
+ `postscript` +	+ boolean +	+ Treats all print jobs as PostScript by prefixing +`%!` at the beginning of each file +	+ `no` +	+ Share +
+ `load printers` +	+ boolean +	+ If `yes`, automatically loads each printer in the +printcap file as printing shares +	+ `yes` +	+ Global +
+ `print command` +	+ string (shell command) +	+ Unix command to perform printing +	+ See below +	+ Share +
+ `lpq command` +	+ string (shell command) +	+ Unix command to return the status of the printing queue +	+ See below +	+ Share +
+ `lprm command` +	+ string (shell command) +	+ Unix command to remove a job from the printing queue +	+ See below +	+ Share +
+ `lppause command` +	+ string (shell command) +	+ Unix command to pause a job on the printing queue +	+ See below +	+ Share +
+ `lpresume` `command` +	+ string (shell command) +	+ Unix command to resume a paused job on the printing queue +	+ See below +	+ Share +
+ `printcap name` + + `(printcap)` +	+ string (filename) +	+ Location of the printer capabilities file +	+ System-dependent +	+ Global +
+ `min print space` +	+ numeric (size in kilobytes) +	+ Minimum amount of free disk space that must be present to print +	+ `0` +	+ Share +
+ `queuepause` `command` +	+ string (shell command) +	+ Unix command to pause a queue +	+ See below +	+ Share +
+ `queueresume` `command` +	+ string (shell command) +	+ Unix command to resume a queue +	+ See below +	+ Share +

printing

The printing configuration option tells +Samba which printing system to use. There are +several different families of commands to control printing and print +statusing. Samba supports seven different types, as shown in Table 10-3.

+ +

Table 10-3. Printing system types

+ + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + +

+ Variable +	+ Definition +
+ BSD +	+ Berkeley Unix system +
+ SYSV +	+ System V +
+ CUPS +	+ Common Unix Printing System +
+ AIX +	+ IBM's AIX operating system +
+ HPUX +	+ Hewlett-Packard Unix +
+ QNX +	+ QNX Realtime Operating System +
+ LPRNG +	+ LPR Next Generation +
+ SOFTQ +	+ SOFTQ system +
+ PLP +	+ Portable Line Printer +

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.

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 the printing styles listed in +Table 10-3, simply set the commands for each of +these manually.

+ + +

+ + + +

printable

The printable option must be set to +yes 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

printer

The option, also 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

lpq cache time

The global lpq cache +time option allows you to set the number of +seconds for which 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 that it can report to users. 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. A time setting of 0 disables caching of queue +status. The following example resets the time to 30 seconds:

[deskjet]
+    lpq cache time = 30

postscript

The postscript option forces the +printer to treat all data sent to it as PostScript. It does this by +prefixing the characters %! to 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

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 the system equivalent). For +example, if your +printcap file looks +like this:[3]

+ +

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

+ +

the shares [lp] and [laser] are +automatically created as valid print shares when Samba is started. +Both shares borrow the configuration options specified in the +[printers] section to configure themselves and are +available in the browse list for the Samba server. The default value +for this option is yes. If you prefer to specify +each printer explicitly in your configuration file, use the +following:

+ +

[global]
+    load printers = no

+ + +

+ + + +

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.

+ + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + +

The default values for each option are dependent on the value of the +printing option. Table 10-4 +shows the default commands for each printing option. The most popular +printing system is BSD.

+ +

Table 10-4. Default commands for various printing options

+ Option +	+ BSD, AIX, PLP, LPRNG +	+ SYSV, HPUX +	+ QNX +	+ SOFTQ +
+ `print` `command` +	+ `lpr -r -P%p %s` +	+ `lp -c -d%p %s; rm` `%s` +	+ `lp -r -P%p %s` +	+ `lp -d%p -s %s; rm %s` +
+ `lpq` `command` +	+ `lpq -P%p` +	+ `lpstat -o%p` +	+ `lpq -P%p` +	+ `lpstat -o%p` +
+ `lprm` `command` +	+ `lprm -P%p %j` +	+ `cancel %p-%j` +	+ `cancel %p-%j` +	+ `cancel %p-%j` +
+ `lppause` `command` +	+ `lp -i %p-%j -H` `hold` + + (SYSV only) +	+ None +	+ None +	+ None +
+ `lpresume` `command` +	+ `lp -i %p-%j -H` `resume` + + (SYSV only) +	+ None +	+ None +	+ `qstat -s -j%j -r` +

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

If the printcap +name option (also called +printcap) appears in a printing share, Samba uses +the file specified as the system printer capabilities file (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 the filename (with its complete path +specified) of a printer capabilities file on the server:

[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

The min print +space option sets the amount of space that must be +available on the disk that contains the spool directory if printing +is to be 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 to avoid having print jobs fill +up the remaining disk space on the server, which can cause other +processes to fail:

[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

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.