HP X.25/9000 User's Guide HP-UX 11i v3 (5900-1523, August 2011)

If the application and cud fields do not appear in the pad_spt file, the /bin/login (default)
program is automatically launched.
CAUTION: Use extreme caution when specifying applications other than the default (login)
application. Since the x29server process is started with superuser privileges, it gives root privileges
to applications triggered by incoming calls.
You can automatically launch a user application by:
• configuring the application field with the relevant application name as its value without
specifying the cud field. The application name must be the full path name of the application
to be launched.
• configuring the application field with the application name and setting the cud field to yes. In
this case, the cud field is considered as the argument to the application. The application name
must be the full path name of the application to be launched.
• not including the application field and setting the cud field to yes. This allows the application
to be defined by the incoming Call Request Packet.
The first four bytes of the CUD field (in call request packets) are NOT part of the application’s full
path name. The first four bytes are used for protocol ID as explained in the section “Call acceptance
mechanism and system security.”
Remote PAD printer support (x29printd)
Overview
The x29printd user-level program provides support for printers attached to remote PADs. It
accesses X.25 level 3 through Berkeley Sockets (programmatic interface). It also has an interface
to special PTYs (see illustration below).
Figure 25 Remote printer support
When x29printd begins execution, it examines the /etc/x25/x29hosts file for all PAD
devices configured with a PAD type printer. For each of these configured devices, x29printd
monitors all print requests sent to the spooling system (see “X.25 Configuration files and examples”
(page 144) for an example of the x29hosts file).
When x29printd detects a print request, it establishes an SVC with the remote PAD printer
specified in the remote X.121 address. x29printd then transmits the print data to the remote
PAD printer, closes the SVC, and waits for another print request.
Remote PAD printer support (x29printd) 99