Devices(4)Devices(4)NAMEDevices - Contains information about devices on the local system that
can establish a connection to a remote computer using the uucp program
SYNOPSIS
/usr/lib/uucp/Devices
DESCRIPTION
The /usr/lib/uucp/Devices file contains information about the devices
on the local system that can establish a connection to a remote com‐
puter using the uucp program. This file includes information about
hardwired, telephone, and TCP/IP communications links.
Note that only someone with root user authority can edit the Devices
file, which is owned by the uucp login ID.
Fields in the Devices File
The Devices file must contain a description of each device on the local
system that can establish a remote connection using the uucp program.
Each line in the Devices file includes the following fields: Typically
specifies the type of hardwired (DIR) or Automatic Calling Unit (ACU)
device. Specifies the device name for the port. Specifies the dialer
name if the Line entry specifies an 801 dialer. Typically specifies
the transmission speed. Specifies a particular type of autodialer
(modem) and the token (a defined string of characters) that is passed
to the dialer. Valid entries for this field are defined in the
/usr/lib/uucp/Dialers file.
The fields appear on the line as follows:
Type Line Line2 Class Dialer-Token Pairs
There must be an entry in every field of a line in the Devices file.
If a field does not apply to the particular type of device, use a -
(dash) as a placeholder.
Lines in the Devices file cannot wrap. Each entry must be on only one
line in the file. However, the Devices file can contain blank lines
and comment lines. Comment lines begin with a # (number sign). Blank
lines are ignored. Enter one of the following keywords in the Type
field: Use this keyword, entered in uppercase letters, if your site
connects multiple systems over the telephone network using automatic
calling units (autodialers or modems). Use this keyword if your site
uses hardwired lines to connect multiple systems. Use this keyword if
your site uses TCP/IP. Enter the name of a particular remote system
hardwired to the local system. The SystemName keyword is the name
assigned to each individual system; for example, hera, zeus, or merlin.
This field corresponds to the Type field in the
/usr/lib/uucp/Systems file. Enter the device name for the line,
or port, used in the communications link. For example, use the
appropriate tty device name for a hardwired line, such as tty01.
For a line connected to an ACU (a modem), use a device name
appropriate to the dialer, such as tty01 or tty0. For a TCP
connection, enter a - (dash) as a placeholder. If you are using
an 801 dialer, enter the device name of the 801 ACU in this
field. For example, if the entry in the Type field is ACU and
the Line field entry (specifying the modem) is tty0, the Line2
field entry (specifying the 801 dialer for the modem) might be
tty01. If the device type is not 801, enter a - (dash) in this
field as a placeholder.
Note that the Line2 field is used only to support older modems
that require 801-type dialers. The modem is plugged into one
serial port, and the 801 dialer is plugged into a separate
serial port. For an ACU or a hardwired line, the Class field
can be the speed of the device. In this case, for a hardwired
line, enter the transmission rate of the device connecting the
two systems. For a telephone connection, enter the speed at
which the ACU transmits data, such as 300 or 1200 bps.
This field can also contain a letter with a speed (for example,
C1200, D1200) to differentiate between classes of dialers. For
example, some offices have more than one telephone network, one
for internal use and one for external communications. In such a
case, it is necessary to distinguish which lines should be used
for each connection.
For devices that can match any speed, you can specify Any in
this field.
The Class field in the Devices file is matched against the Class
field in the /usr/lib/uucp/Systems file. For example, if the
Systems file entry for system hera is:
hera Any ACU 1200 3-3-5-2 ogin: nuucp ssword: oldoaktree
The uucp program searches for an entry in the Devices file with
a Type of ACU and a Class of 1200.
Some devices can be used at several speeds. In this case, make
multiple entries for the device, specifying each speed on a sep‐
arate line in the Devices file. If the uucp program cannot con‐
nect at the first speed, it will try the other speeds, one after
another.
For a TCP connection, enter a - (dash) as a placeholder. The
Dialer-Token Pairs field specifies a particular type of autodi‐
aler (modem) and the token (a defined string of characters) that
is passed to the dialer. Valid entries for this field are
defined in the /usr/lib/uucp/Dialers file.
For a hardwired connection, enter the word direct (note the low‐
ercase d) as the Dialer entry and leave the Token entry blank.
For a telephone connection, enter the type of dialer and the
token that is passed on to that modem. The Token field entry is
either a telephone number or a predefined string used to reach
the dialer.
For a telephone connection, enter one of the following as the
Dialer field entry: A Hayes dialer. A Penril dialer. Other
dialers that you can specify by including the relevant informa‐
tion in the /usr/lib/uucp/Dialers file. A TCP/IP connection.
Enter TCP in the Dialer field entry if you have also entered TCP
in the Type field.
Each Dialer field entry included as part of a Dialer-Token Pairs
field in the Devices file has a corresponding entry in the
Dialers file.
If the Token field entry represents a telephone number, enter
one of the following in the Token field to specify how the uucp
program should use the telephone number listed in the
/usr/lib/uucp/Systems file: The default token in a Dialer-Token
Pairs field. The \D token specifies that the uucp program should
take the phone number listed in the /usr/lib/uucp/Systems file
and pass it to the appropriate dialer script (entry) in the
/usr/lib/uucp/Dialers file without including a dial-code abbre‐
viation. This token instructs the uucp program to process the
phone number by including the data specified in the
/usr/lib/uucp/Dialcodes file.
Note that if you are using dial-code abbreviations specified in
theDialcodes file for certain telephone numbers, you must enter
the \T string as the token in those entries in the Dialers file.
Leaving the Token field blank is the same as entering \D, so a
blank is usually sufficient as a token if you have included com‐
plete telephone numbers in the /usr/lib/uucp/Systems file.
If the Token field does not represent a telephone number, enter
the predefined string necessary to reach the dialer.
Entries for Hardwired Connections
In general, each entry for a hardwired connection consists of two
lines. The first line specifies the port (line) that the uucp command
uses to connect to the remote system. The second line specifies the
remote system. However, if the two systems use a permanent virtual
circuit connection, the entry is a single line in the Devices file.
To set up a hardwired connection specifying a port and a remote system,
make a 2-line entry as follows: Enter the keyword Direct, with an
uppercase D, in the Type field in the first line of the entry. Enter
the name of the remote system to which you want to connect the local
computer over the hardwired line in the Type field in the second line
of the entry. Enter the device name appropriate for the hardwired con‐
nection used at your site in the Line field in both lines of the entry.
Enter a - (dash) for a placeholder in the Line2 field in both lines of
the entry. Enter the transmission rate appropriate for the hardwired
connection used at your site in the Class field in both lines of the
entry. Enter direct (all lowercase) in the Dialer-Token Pairs field in
both lines of the entry.
To set up a hardwired connection between two systems that use a perma‐
nent virtual circuit connection, make a 1-line entry as follows: Enter
the name of the remote system in the Type field. Enter the name of the
permanent virtual circuit connection in the Line field. Enter a -
(dash) for a placeholder in the Line2 field. Enter the transmission
rate appropriate for the hardwired connection used at your site in the
Class field. Enter direct (all lowercase) in the Dialer-Token Pairs
field.
Continue adding entries to the Devices file until you have listed each
hardwired device connecting the local system to a remote system.
Entries for Autodialer Connections
In telephone-connection entries, the Type field is specified as an ACU.
Enter ACU as the Type field entry in all remote connections established
over a phone line. To set up Devices file entries for autodialer con‐
nections, make a 1-line entry for each modem as follows: Enter ACU in
the Type field. The Line field contains the name of the device that is
attached to the modem. Enter the device name appropriate for your
site. Enter a - (dash) as a placeholder in the Line2 field, unless the
autodialer is a standard 801 dialer. If the autodialer is a standard
801 dialer, enter 801. In the Class field, enter the baud rate appro‐
priate for your modem and line (this can be 300, 1200, 2400, or higher,
depending on the modem) or the class of your modem (for example,
D2400). Note that if the modem can be used at more than one rate, make
a separate entry in the Devices file for each rate. Enter the name of
the modem as the Dialer field entry in the Dialer-Token Pairs field. If
you are planning to include complete phone numbers in the
/usr/lib/uucp/Systems file, leave the Token field blank. (A blank
instructs the uucp program to use the default \D token.) If you are
planning to use dial-code abbreviations specified in the
/usr/lib/uucp/Dialcodes file, enter the \T token.
Continue adding entries to the Devices file until you have listed each
connection between the local system and a remote system that uses a
telephone line and a modem.
Entries for Use with TCP/IP
If your site is using the TCP/IP system, include the relevant TCP/IP
entry in the Devices file. To set up the file for use with the TCP/IP
system, enter a line in the Devices file as follows: Enter TCP in the
Type field. Enter dashes in the Line, Line2, and Class fields. Enter
TCP as the Dialer field entry and leave the Token field blank.
EXAMPLES
Examples of Devices file entries for a number of situations are given
below.
Setting Up Entries for Hardwired Connections
To set up a Devices file entry specifying a port and a remote system,
enter: Direct tty0 - 1200 direct
zeus tty0 - 1200 direct
The Type field lists Direct (for a direct connection) in the
first part and zeus (the name of the remote system) in the sec‐
ond part. The local system is connected to system zeus by way
of device tty0, which is listed in the Line field in both parts
of the example.
The Line2 field contains actual data only when the entry speci‐
fies a certain type of telephone connection. A - (dash) is used
as a placeholder in other types of connections, as is the case
in this example. This tty device transmits at 1200 bps, which
is listed in the Class field in both parts of the example. The
word direct in the Dialer portion of the Dialer-Token Pairs
field indicates that this is a direct connection. To set up a
Devices file entry specifying a permanent virtual circuit con‐
nection, enter: odin tty01 - 9600 direct
The Type field lists the name of the remote system, odin. The
Line field contains the name of the permanent virtual circuit
connection. A - (dash) is used as a placeholder in the Line2
field. This line transmits at 9600 bps, which is listed in the
Class field. The word direct in the Dialer portion of the
Dialer-Token Pairs field indicates that this is a direct connec‐
tion.
Setting Up Entries for Autodialer Connections
For a standard Hayes modem that can be used at only one baud rate,
enter: ACU tty2 - 1200 hayes
The Type field is specified as ACU. The Line field is specified
with the device name tty2. Because this modem is not an 801
dialer, a - (dash) is used as a placeholder in the Line2 field.
The Class field entry is a transmission rate of 1200 baud. The
Dialer part of the Dialer-Token Pairs field is specified as a
hayes modem, and the Token part is left blank. To specify a
standard Hayes modem that can be used at different baud rates,
enter: ACU tty3 - 1200 hayes
ACU tty3 - 300 hayes
These two lines specify the same modem, a hayes modem that can
be used at either 1200 or 300 baud, as specified in the Class
field. The modem is connected to a device named tty3 (the Line
field), and the Line2 field contains the - (dash) placeholder.
The Dialer part of the Dialer-Token Pairs field is specified as
a hayes modem, and the Token field is left blank. To specify a
connection using a standard 801 dialer, enter: ACU tty4 tty5
1200 801
ACU tty6 tty7 300 801
In these entries, the ACU entries are connected to devices named
tty4 and tty6, specified in the Line field. In both cases, there
is an entry in the Line2 field because a standard 801 autodialer
is specified in the Dialer-Token Pairs field. Because 801 is
specified as the dialer in these two examples, the Line2 field
must contain the device names of the 801 ACUs. The Class field
entry is a transmission rate of 1200 baud for the first example
and 300 for the second. The Token part of the Dialer-Token
Pairs field is blank.
Setting Up Entries for Use with TCP/IP
If your site is using the TCP/IP system, enter the following in the
Devices file: TCP - - - TCP
TCP is specified in the Type field. Dashes are used as placeholders in
the Line, Line2, and Class fields. TCP is specified as the Dialer
field entry with the Token entry left blank.
Setting Up Entries for Both Local and Remote Systems
The following examples illustrate the entries needed in the Devices
file for both local and remote systems in order for the two systems to
communicate using the uucp program.
The following entries configure local and remote Devices files for a
hardwired connection between systems zeus and hera, where zeus is con‐
sidered the local system and hera is considered the remote system. The
hardwired device is tty0. The Devices file on system zeus must contain
the following entry in order to connect to the remote system hera:
Direct tty0 - 1200 direct
hera tty0 - 1200 direct The Devices file on system hera must con‐
tain the following entry for communications with system zeus: Direct
tty0 - 1200 direct
zeus tty0 - 1200 direct
The following entries are set up to connect systems venus and
merlin over a telephone line using modems. System venus is con‐
sidered the local system, and system merlin is considered the
remote system.
On both systems, the tty01 device is hooked to a hayes modem at 1200
baud. Both computers include partial phone numbers in their
/usr/lib/uucp/Systems files and dialing codes in their
/usr/lib/uucp/Dialcodes files. The Devices file on system venus must
contain the following entry for the connection to system merlin: ACU
tty01 - 1200 hayes \T The Devices file on system merlin must con‐
tain the following entry for the connection to system venus: ACU tty01
- 1200 hayes \T
FILES
Contains all the configuration files for the uucp program, including
the Devices file Contains dial-code abbreviations Specifies initial
handshaking on a connection Describes accessible remote systems
SEE ALSO
Daemons: uucico(8)
Commands: cu(1), uucp(1), uuto(1), uux(1)Devices(4)