pcnfsd, rpc.pcnfsd - The (PC)NFS authentication and print request server
The pcnfsd daemon is an server that supports ONC clients on PC (DOS, OS/2,
Macintosh, and other) systems. This reference page describes Version 2 of
the pcnfsd server.
The rpc.pcnfsd daemon is started via /etc/rc.config by default. It can be
turned off by running nfssetup and by answering 'no' to the appropriate
question. The pcnfsd daemon reads the /etc/pcnfsd.conf configuration file
if present, and then services RPC requests directed to program number
150001. This release of the pcnfsd daemon supports both Version 1 and Ver-
sion 2 of the pcnfsd protocol.
The requests serviced by pcnfsd fall into three categories: authentication,
printing, and other. Only the authentication and printing services have
This program can be redistributed freely.
When pcnfsd receives a PCNFSD_AUTH or PCNFSD2_AUTH request, it "logs in"
the user by validating the user name and password and returning the
corresponding UID, GIDs, home directory, and umask.
By default, pcnfsd only allows authentication requests for users with UIDs
in the range 101 to 60002. (This corresponds in SVR4 to the range for non-
system accounts.) To override this, you can add a line in the following
format to the /etc/pcnfsd.conf file. Here each range is either of the fol-
lowing forms indicating an inclusive range:
The pcnfsd daemon supports a printing model based on the use of NFS to
transfer the actual print data from the client to the server. The client
system issues a PCNFSD_PR_INIT or PCNFSD2_PR_INIT request, and the server
returns the path to a spool directory that the client can use and that is
exported by NFS. The pcnfsd daemon creates a subdirectory for each of its
clients: the parent directory is normally /usr/spool/pcnfs and the sub-
directory is the host name of the client system. You must also export the
/usr/spool/pcnfs directory to the PC clients. If you want to use a dif-
ferent parent directory, add a line of the following format to the
Once a client has mounted the spool directory by using NFS and has
transferred print data to a file in this directory, the client issues a
PCNFSD_PR_START or PCNFSD2_PR_START request. The pcnfsd daemon handles
this, and most other print-related requests, by constructing a command
based on the printing services of the server operating system and by exe-
cuting the command using the identity of the PC user. Since this involves
set-user-id privileges, pcnfsd must be run as root.
Every print request from the client includes the name of the printer which
is to be used. This name corresponds to a printer definition in the
/etc/printcap database. If you want to define a nonstandard way of process-
ing print data, you should define a new printer and arrange for the client
to print to this printer. There are two ways of setting up a new printer.
The first involves the addition of an entry to /etc/printcap and the crea-
tion of filters to perform the required processing. This is outside the
scope of this discussion. In addition, pcnfsd includes a mechanism by which
you can define virtual printers known only to pcnfsd clients. Each printer
is defined by a line in the /etc/pcnfsd.conf file of the following format:
printer name alias-for command
The name variable is the name of the printer you want to define and the
alias-for variable is the name of a ``real'' printer that corresponds to
this printer. For example, a request to display the queue for name is
translated into the corresponding request for the printer alias-for. If
you have defined a printer in such a way that there is no "real" printer to
which it corresponds, use a single dash (-) for this field. (See the defin-
ition of the printer test below for an example.) The command variable is a
command that will be executed whenever a file is printed on name. This com-
mand is executed by the Bourne shell, /bin/sh, using the -c option. For
complex operations you should construct an executable shell program and
invoke that in command. Within command, the following tokens will be
Replaced by the full pathname of the print data file.
When the command has been executed, the file will be
Replaced by the user name of the user logged in to the
$HOST Replaced by the host name of the client system.
The printer test is used only for testing. Any file sent to this printer
will be copied into /usr/tmp. Any request to list the queue, check the
status, and so on of printer test will be rejected because the alias-for
has been specified as a dash (-).
The pcnfsd configuration file.
Commands: lp(1), lpq(1), lpstat(1)