The UNIX-to-UNIX Copy Program (UUCP) is a group of programs that enables batched, error-free file transfer and remote command execution between two UNIX systems. UUCP is typically used to transfer electronic mail, network nets, and public domain software over low-speed, low-cost communications links. Digital UNIX implements the HoneyDanBer version of UUCP.
This chapter describes the UUCP environment, how to plan for UUCP, how to
configure your system for UUCP, and how to manage it. For general information
about UUCP see
uucp_intro(7).
For information on how to use UUCP, see the
Command and Shell User's Guide.
In the UUCP environment, systems can be connected to each other in the following ways:
Figure 9-1 shows two simple UUCP configurations. Figure 9-2 shows a sample UUCP configuration on a LAN in which Host A has a TCP/IP connection with Host C.
This section describes those tasks you need to do before configuring UUCP.
In verifying the correct hardware, you are verifying both the cables and modems, if used.
Make sure you are using the correct cable to connect to the serial port of your system. If you do not, you might experience signal loss and the software will fail to function properly.
If the two systems are in close proximity to each other, use one of the null modem cables listed in Table 4-1.
If the two systems are connected through modems and telephone lines, see Table 4-6 for a list of modem cables to use.
When using modems with UUCP, adhere to the following guidelines:
UUCP can also be configured to run over TCP/IP local area networks (LANs).
For information on running UUCP over a LAN, see
uucp_manual_setup(7).
UUCP configuration consists of the following parts:
The type of information you need depends on the types of connections you plan to set up and use.
Appendix A contains a worksheet that you can use to record the information that you need to provide to configure UUCP.
Figure 9-3 shows Part 8A of the Configuration Worksheet.
If you are viewing this manual online, you can use the print feature to print a copy of this part of the worksheet. The sections that follow explain the information you need to record in Part 8A of the worksheet.
For modem connections, supply the following information:
/usr/lib/uucp/Devices
file. For more information, see
uucp_manual_setup(7).
/dev
directory.
uugetty
process entry in the
/etc/inittab
file. The
uugetty
process sets up speed, terminal flags, and the line discipline for managing
terminals. For more information, see
uugetty(8).
Note
The
uugettycommand should only be run on RS-232 lines, not printer or console lines.
For direct link connections, supply the following information:
If you want to connect to any system to which you have a direct hardwired connection, check Direct.
/dev
directory.
uugetty
process entry in the
/etc/inittab
file. The
uugetty
process sets up speed, terminal flags, and the line discipline for managing
terminals. For more information, see
uugetty(8).
Note
The
uugettycommand should only be run on RS-232 lines, not printer or console lines.
For TCP/IP connections, supply the following information:
/usr/lib/uucp/Devices
file.
Otherwise, check NO.
/etc/inetd.conf
file is modified. In addition, you must
stop and restart the
inetd
daemon to be able to accept UUCP calls over TCP/IP.
Otherwise, check NO.
Figure 9-4 shows Part 8B of the Configuration Worksheet.
If you are viewing this manual online, you can use the print feature to print part of the worksheet. The following sections explain the information you need to record in Part 8B of the worksheet.
g
-- Specifies to use the default protocol, which provides
error checking.
t
-- Presumes an error-free channel and therefore is not
reliable for use with modem connections.
e
-- Used to communicate with sites that are running both
Digital UNIX and other UNIX versions of UUCP.
f
-- Relies on flow control of the data stream. It is
meant for working over links that can virtually be guaranteed to be error free,
specifically X.25/PAD links.
/usr/lib/uucp/Devices
file, or you can specify
any,
if the device can be used at any speed.
A dialing prefix is defined in the
/usr/lib/uucp/Dialcodes
file.
The
/usr/lib/uucp/Dialcodes
file contains dial code abbreviations and partial phone numbers that complete
the telephone entries in the
/usr/lib/uucp/Systems
file. Entries in the
/usr/lib/uucp/Dialcodes
file contain an alphabetic prefix
attached to a partial phone number that can include, for example, access codes,
area codes, and exchange numbers.
If you know the dialing prefix, enter it on the worksheet. If none is defined, enter it and the sequence of numbers to be associated with the prefix.
/etc/passwd
file on the remote system. Ask
the administrator of the remote system for the login name and password that is
assigned to your system on the remote system. The administrator of the remote
system must include the login name and password for your system in the remote
system's
/etc/passwd
file.
Note
Although the password for the login ID on the remote system is required in order to configure UUCP, do not write the password on this worksheet to protect system security.
expect-send
string to be used immediately before
performing the login on the remote system. You can choose one of the following:
expect-send
strings.
expect-send
strings.
Modems usually use a series of carriage returns as an
expect-send
string.
For more information on
expect-send
strings, see
Systems(4).
Figure 9-5 shows Part 8C of the Configuration Worksheet.
If you are viewing this manual online, you can use the print feature to print a copy of this part of the worksheet. The sections that follow explain the information you need to record in Part 8C of the worksheet.
/etc/passwd
file on your system.
By convention, the login ID that you assign to a remote system
establishing incoming connections is the system name prefixed with a
U (uppercase u). For example, if you specify
machine1
for incoming connections, the login ID, by convention, is
Umachine1;
however, you can select any login ID.
You also have the option of adding a comment to the
/etc/passwd
file for this login ID.
You have the option to assign more than one one login ID for each incoming system. Assigning multiple logins to a remote system allows you to maintain better access control for users on the remote system. With multiple logins, you can grant privileged users on the remote system more access on your system than you do to nonprivileged users. With multiple logins, you can assign multiple sets of permissions.
You must provide this information to the administrator of each remote system that will connect to your system as an incoming system.
If you check YES, remote system users can transfer files to and execute commands on a local system more easily. If security is a consideration, you can restrict this access so that the local system retains control of file transfers and command executions initiated by remote systems.
Security considerations at your site might require that you limit a remote
system's access to the local system by using the default value
CALL
for this option.
READ
and
WRITE
options,
uucp
permits files to be transferred only to the
/usr/spool/uucppublic
directory.
However, if you specify pathnames in these options, you must enter the pathname
for every source and destination. If you enter a pathname in either option,
you must also explicitly specify the public directory if you want
uucico
to be allowed to place files in that location.
READ
and
WRITE
options.
/usr/lib/uucp/Permissions
file. The default is the command
rmail
only.
If you use this option, no other other ID from the remote system can call in.
Several systems, however, can use the same ID. The
VALIDATE
option is meaningful only when the login ID and password are protected.
If both systems use the
CALLBACK
option in their respective
Permissions
files, they will never be able to communicate
with each other.
After you complete the required UUCP planning
(Section 9.2),
use the
uucpsetup
script to configure UUCP. To invoke the
uucpsetup
script, log in as superuser and either
choose the UNIX-to-UNIX Copy Program (UUCP) option from
the Setup Menu or enter the following command:
#
/usr/sbin/uucpsetup
The
uucpsetup
script prompts you for information required to
configure connections, incoming systems, and outgoing systems.
Table 9-1
summarizes the various
uucpsetup
command syntaxes:
| Use this command: | If you want to: |
uucpsetup
|
Configure connections, incoming systems, and outgoing systems. |
uucpsetup -i
|
Configure the incoming systems only. |
uucpsetup -m
|
Modify UUCP connections. |
uucpsetup -o
|
Configure the outgoing systems only. |
uucpsetup -p
|
Configure the
Poll
file.
|
For information about other options, see
uucpsetup(8).
The following sections provide information on how to configure connections,
incoming systems, outgoing systems, and the
Poll
file.
After you invoke
uucpsetup,
use the the information you gathered in
Section 9.2.2.1
to configure UUCP connections.
The following guidelines explain how to answer some of the script questions:
tty01,
enter 1.
/etc/inittab
entry ID -- The script prompts you for the
Identifier
field and asks if this entry will be
used in shared mode. It automatically supplies information for the other
fields. No two processes can have the same ID.
The following example illustrates how to select the process ID (PID)
u4:
Select an ID for the process in /etc/inittab file
For example type 'u1':
u4
The ID that you select is checked against those that exist in the
/etc/inittab
file. If the ID that you assign exists,
the
uucpsetup
script prompts you to enter another ID.
You must also indicate whether the system will use the modem or direct line in shared mode.
For more information on the
/etc/inittab
file see
inittab(4).
After you invoke
uucpsetup,
use the the information you gathered in
Section 9.2.2.2
to configure UUCP for outgoing
systems. This enables you to use UUCP to connect to other remote systems.
If you are doing a complete UUCP setup, the
uucpsetup
script prompts you for information on outgoing systems when you finish
configuring connections. The following guidelines explain how to answer some
of the script questions:
/usr/lib/uucp/Dialcodes
file. After you enter the
prefix, the script prompts you for the meaning of the prefix. Enter the
sequence of numbers that you want the system to substitute for the prefix. The
following example illustrates how to define the prefix
btown
to be the dialing sequence
1617772:
Enter the prefix for the Dialcodes file; for example "boston"
stands for 9=16171234 :
btown
What telephone number does the prefix stand for; Please include
the long distance access code, area, or country codes;
for example type 9=1617123 :
9=1617772
The
9
in this example is used to obtain a secondary dial tone.
The
9
is site specific; it can be different for your site.
The equal sign (=) is used with the
9,
or number for your site,
and means "wait for the dial tone."
Following the equal sign (=) is the rest of the number. Enter the rest
of the number.
If you define an outgoing TCP system, edit the
/etc/uucp/Systems
file and add an entry for the remote system. The remote system name must be the
fully qualified name.
After you invoke
uucpsetup,
use the the information you gathered in
Section 9.2.2.3
to configure UUCP for incoming
systems. This enables specific remote systems to connect to your system using
UUCP.
If you are doing a complete UUCP setup, the script prompts you for information on incoming systems when you are done configuring outgoing systems.
The first time you add an incoming system, the Incoming Systems Configuration menu prompts you for the name of the system you want to add. After you add an incoming system, this menu offers you the following choices:
Permissions
file but listed in the
Systems
file.
Permissions
file.
The following guidelines explain how to answer some of the script questions:
vipw
command for you to
enter the password for the incoming system. Press Return and, after viewing the
entry in the
/etc/passwd
file, exit the editing session by
entering
:wq.
Then supply a password for the new entry:
Invoking 'vipw'. Press RETURN to continue...
[Return]
root:fQPPWjF20Dfso:0:1:Charles Root:/:/bin/csh
nobody:*Nologin:4294967294:4294967294:anonymous NFS user:/:
daemon:*:1:1:Mr Background,,,:/:
uucp:No Login:2:2:UNIX-to-UNIX Copy:/usr/spool/uucppublic:\
/usr/lib/uucp/uucico
bin:*:3:4:Mr Binary:/bin:
marcy:5jW0VXKeP6n1E:1242:15:Marcy Darcy,,,:\
/usr/users/marcy:/bin/false
Umachine1:H/kj951Fq12ub:2:2:uucp login:/usr/spool/uucppublic:\
/usr/lib/uucp/uucico
~
~
~
"/etc/ptmp" 15 lines, 933 characters
:wq
15 password entries, maximum length 100 You must enter a password Changing password for Umachine1. New password: Retype new password:
You must provide this information to the administrator of each remote system that will connect to your system as an incoming system.
If you define an incoming UUCP system and your system uses NIS, edit the
/etc/passwd
file and add the wildcard
(+:)
as the last line (if not there already).
After you invoke
uucpsetup
with the
-p
option, you configure the
/usr/lib/uucp/Poll
file by completing the following steps:
/usr/lib/uucp/Systems
file as an outgoing system.
Press Return to update the
Poll
file.
Poll
file, enter
y;
otherwise, press Return to exit
uucpsetup.
Monitoring the file transfer queue enables you to determine the status of several types of networking operations, including jobs that have been queued on a local system for transfer to a remote system. General users and system administrators can monitor the file transfer queue.
To get queue status manually, use the
uustat -q
command.
This command lists the jobs (waiting to execute or currently executing) queued for all systems. If a status file exists for a system, its date, time, and status information are reported.
The
uustat
command also allows you to do the following:
uucp
jobs queued to run on remote systems.
uucp
connections to other systems, using the
-m
flag.
-k
flag.
uucp
and
uuto
commands, and requests for command executions generated
with the
uux
command.
See
uustat(1)
for more information on
uustat
flags.
The following example shows all jobs in the current queue: one command file for
system
host4,
three command files for system
host6,
and two command files for system
host8.
The command files for system
host6
have been in the queue for 2 days.
#
uustat -q
host4 1C Sat May 9 11:12:30 1992 SUCCESSFUL host6 3C(2) Sat May 9 11:02:35 1992 CAN'T ACCESS DEVICE host8 2C Sat May 9 10:54:02 1992 NO DEVICES AVAILABLE
You can automatically receive status information about the
uucp
file transfer queue. To enable this mechanism, edit the
/usr/spool/cron/crontabs/uucp
file and delete the
comment character (#) from the beginning of the following line:
# 48 8,12,16 * * * /usr/lib/uucp/uudemon.admin > /dev/null
In the preceding example:
48
|
Represents minutes |
8,12,16
|
Represents hours based on 24-hour clock notation |
* * *
|
Three asterisks are placeholders representing the day of the month, the month of the year, and the day of the week |
The
cron
daemon will run the
uudemon.admin
shell script daily at 48 minutes past the hours 8, 12, and 16; that is, at
8:48 a.m., 12:48 p.m., and 4:48 p.m. The
uudemon.admin
script sends mail to the
uucp
login ID containing queue status information.
Note
These times are the defaults. You can change the time to fit the needs of your site by editing the line in the
/usr/spool/cron/crontabs/uucpfile.
You can also manually run the
uudemon.admin
script. If you do, you should run it at least once a day.
When examining queue status, check the number and age of the file-transfer and
command execution requests queued in the
/usr/spool/uucp/system_name directory. In
some cases, queued jobs remain in the queue for some time, essentially going
undelivered. The status information you need to check includes:
See Appendix F for error messages and solutions.
If necessary, delete the files in the queue, either manually or automatically. See Section 9.5 for information on deleting files.
Each system connected by
uucp
has the following spooling directories:
/usr/spool/uucp/system_name directory is the
uucp
spooling directory. It contains queued local requests for
file transfers and command executions on remote systems. These files are
removed by
uucp
after they are transferred to the designated system.
/usr/spool/uucppublic
directory is the
uucp
public directory. When a user transfers a file to a remote
system or issues a request to execute a command on an other system, the files
generated by these
uucp
commands are stored in the public
directory on the designated system.
Depending upon the size of your installation and the number of files sent to
the local
/usr/spool/uucppublic
directory by users on remote
systems, the public directory can become quite large. Similarly, if requests
are not transferred to remote systems for whatever reasons, the spooling
directory could also become quite large. Therefore, part of
uucp
management is to clean up the spooling directories and conserve disk resources.
To clean up the spooling directories manually, do the following:
uucleanup
command, with the
following syntax:
uucleanup [
options...]
The
uucleanup
program performs the following tasks:
Note
Depending on the size of your installation and the available storage space on the local system, you can set age limit for any length of time. However, you should allow files to remain in the spooling directory for at least the default number of days.
See
uucleanup(8)
for more information on the
uucleanup
command options.
The following example deletes all old files in the
uucp
spooling
and public directories for system
host2
on the local system:
#
uucleanup -shost2
Although automatic cleanup is not enabled when
uucp
is installed, you can enable it by doing the following:
/usr/spool/cron/crontabs/uucp
file and delete the
comment character (#) from the beginning of the following line:
# 45 23 * * * ulimit 5000; /usr/lib/uucp/uudemon.cleanu > /dev/null
In the preceding example:
45
|
Represents minutes |
23
|
Represents hours based on 24-hour clock notation |
* * *
|
Three asterisks are placeholders representing the day of the month, the month of the year, and the day of the week |
The
cron
daemon will start the
uudemon.cleanu
shell script daily at 45 minutes after hour 23; that is, at 11:45 p.m.
The shell script in turn starts the
uucleanup
program. This time
is the default. You can change the time to fit the needs of your site by
editing the line in the
/usr/spool/cron/crontabs/uucp
file.
You can instruct the
cron
daemon to run the
uudemon.cleanu
shell script daily, weekly, or at longer
intervals, depending on the number of
uucico
and
uuxqt
transactions that occur on the local system.
The
uudemon.cleanu
script incorporates the actions of the
uucleanup
program and performs the following additional tasks:
/usr/spool/uucppublic
directory. This helps keep the local file
system from overflowing when users send files to the public directory. If the
local system does not have enough storage space to accommodate a large
/usr/spool/uucppublic
directory, you can change the
30-day default to a shorter time period by modifying the
uudemon.cleanu
shell script.
uucp
spooling directories, including the
public directories, unless you direct it to clean up only the directories of a
specific system by issuing the
uucleanup -s system_name command.
/usr/spool/uucp/.Log
directory, merges them, and places
them in the
/usr/spool/uucp/.Old
directory, which
contains old log information.
uucp
login ID. You can modify the script to send status
information to other login IDs, such as root.
The operating system allots
uucp
a specified amount of storage
space for any one log file; the number of blocks is determined by the default
ulimit.
If the
uudemon.cleanu
script fails to execute because the
ulimit
is set too low for the requirements
of the local system, you should increase the value.
See
uudemon(8)
for more information on command options.
When removing files from the queue, observe the guidelines for the following files:
uucleanup
or
uudemon.cleanu
script. The execute files are still queued
because the data files required to execute the specified command on the
designated system were not transferred. Since data files are generally sent at
the same time as execute files, the transfer probably failed at the point of
destination. Execute files are named
X.filename and
data files are named
D.filename.
uucleanup
or
uudemon.cleanu
script. Command files are named
C.filename.
The
uucp
program creates a log file for each remote system with
which your local system communicates. Each time you use the networking
utilities facility,
uucp
places status information about each
transaction in the appropriate log file. Log file names can be in either of
the following forms:
/usr/spool/uucp/.Log/daemon_name/system_name
/usr/spool/uucp/.Log/command_name/system_name
In the preceding example:
daemon_name
|
Represents either
uucico
(called by the
uucp
and
uuto
commands) or
uuxqt
(called by the
uux
command)
|
command_name
|
Represents either
uucp
or
uux
|
system_name
|
Represents the name of the system with which your local system is communicating |
To display individual log files, use the
uulog
command, with
the following syntax:
uulog [options...]
You can use the
uulog
command to display a summary of
uucp
and
uux
requests by user or by system. See
uulog(1)
for more information on the
uulog
command and its options.
Instead of viewing the log files individually, you can have the
uudemon.cleanu
script automatically append these log files to
one primary log file, and then view only the one log file.
The
uudemon.cleanu
script combines the
uucico,
uuxqt,
uux,
and
uucp
log files on a system and stores them in a directory named
/usr/spool/uucp/.Old.
By default, the
uudemon.cleanu
script saves log files that are up to 2 days old.
You can change the default by modifying the
-o2
option in the
following line in the
uudemon.cleanu
script:
uucleanup -D7 -C7 -X2 -o2 -W1
If storage space is a problem on a particular system, consider reducing the
number of days that the files are kept in the individual log files.
See
Section 9.5
for information on setting up the
uudemon.cleanu
script.
The following command displays the log file for
uucico
requests for system
host2:
#
uulog -s host2
The following command displays the log file for
uuxqt
requests for system
host1:
#
uulog -x host1
The following command displays the last 40 lines of the file transfer
log for system
host6
and executes a
tail -f
command. Press Ctrl/C to terminate the command.
#
uulog -f host6 -40
The following two system log files are affected by
uucp:
/usr/adm/sulog
file contains a history of superuser
(su)
command usage. The
uudemon
entries in the
/usr/spool/cron/crontabs/uucp
file each use the
su
command.
/usr/adm/cron/log
file contains a history of all the
processes generated by the
cron
daemon.
Both files can grow quite large over a period of time. Purge these files periodically to keep them at a reasonable size. See System Administration for information on these files.
The
Maxuuxqts
file, located in the
/usr/lib/uucp
directory, limits the number of
uuxqt
processes running
simultaneously on a local system. Typically, the file requires no
configuration or maintenance unless the system on which it is installed is
utilized frequently and heavily by users on remote systems.
To change the number of
uuxqt
processes on the system, edit the
Maxuuxqts
file and change the ASCII number to meet the needs of
your installation; the default is 2. In general, the larger the number, the
greater the potential load on the local system.
When users issue
uucp
commands to copy files and execute remote
commands, the files containing these work requests are queued for transfer in
the local
/usr/spool/uucp/system_name directory. The
uucp
daemon
uusched
schedules the transfer of these files.
To schedule jobs, start the
uusched
daemon by using the
uusched
command, with the following syntax:
uusched [
options...
]
The following options are available:
-x debug_level
|
Produces debugging information about the progress of the
uusched
activity. The valid range for the debugging level is 0 to 9, with a default of
5. Higher numbers produce more detailed debugging information.
|
-u debug_level
|
Passes the
-xdebug_level specification on to the
uucico
daemon, which then produces debugging output about the
file-transport activities.
|
Although you can start the
uusched
daemon manually, the
preferred method is to start it automatically at specified intervals by using
the
uudemon.hour
shell script, which is stored in
/usr/lib/uucp.
The shell script, in turn, is started periodically by the
cron
daemon, based on instructions in the
/usr/spool/cron/crontabs/uucp
file.
The
/usr/lib/uucp/Maxuuscheds
file limits the number of remote systems that the
uucico
program can contact at any one time.
This file is used in conjunction with the
uusched
daemon and the
lock files in the
/usr/spool/locks
directory to determine
the number of systems currently being polled.
The
Maxuuscheds
file requires no configuration or maintenance
unless the system on which it is installed is utilized frequently and heavily
by users on remote systems. You use this file to help manage system resources
and load averages.
The
Maxuuscheds
file contains an ASCII number that you can
change in order to meet the needs of your installation; the default is 2. In
general, the larger the number, the greater the potential load on the local
system.
See
uusched(8)
for more information on the
uusched
command and its options.
The following command starts
uusched
daemon manually as a background process:
#
/usr/lib/uucp/uusched &
The
uudemon.hour
shell script is used in conjunction with the
Poll
file, the
uudemon.poll
shell script, and the
/usr/spool/cron/crontabs/uucp
file to initiate calls to remote systems. Specifically,
uudemon.hour
calls programs involved in transferring files between systems at specified
hourly intervals.
You can instruct the
cron
daemon to run the
uudemon.hour
shell script at specified
hourly intervals. The frequency at which you run the script depends on the
amount of file transfer activity originating from the local computer.
Although the
uudemon.hour
shell script is not enabled when
uucp
is installed, you can enable it by doing the following:
/usr/spool/cron/crontabs/uucp
file and delete the comment character (#) from the beginning of the following
line:
# 25,55 * * * * /usr/lib/uucp/uudemon.hour > /dev/null
In the preceding example:
25,55
|
Represents minutes past the hour |
* * * *
|
Four asterisks are placeholders representing the hour interval, the day of the month, the month of the year, and the day of the week |
The
cron
daemon will run the
uudemon.hour
script at 25 minutes past the hour and again at 55 minutes past the hour; for
example, at 8:25 a.m. and 8:55 a.m., 9:25 a.m. and 9:55 a.m., and so on.
These times are the defaults. You can change the time to fit the needs of your
site by editing the line in the
/usr/spool/cron/crontabs/uucp
file.
If users on the local system initiate a large number of file transfers, you
might need to specify that the
cron
daemon should start
uudemon.hour
several times an hour. If the number of file
transfers originating from the local system is low, you can probably specify
a start time once every 4 hours, for example.
The
uudemon.poll
shell script is used in conjunction with the
Poll
file, the
uudemon.hour
shell script, and the
/usr/spool/cron/crontabs/uucp
file to initiate calls to remote systems. The
uudemon.poll
shell script polls the systems listed in the
Poll
file,
/usr/lib/uucp/Poll.
In addition, it creates command files for the systems listed in the
Poll
file.
The time at which you run
uudemon.poll
depends on the time at which you run
uudemon.hour.
You generally schedule the polling
shell script to run before the hourly script. This schedule enables
uudemon.poll
to create any required command files before the
cron
daemon runs
uudemon.hour.
Although
uudemon.poll
is not enabled when
uucp
is installed, you can enable it by doing the following:
/usr/spool/cron/crontabs/uucp
file and delete the comment character (#) from the beginning of the following
line:
# 20,50 * * * * /usr/lib/uucp/uudemon.poll > /dev/null
In the preceding example:
20,50
|
Represents minutes past the hour |
* * * *
|
Four asterisks are placeholders representing the hour interval, the day of the month, the month of the year, and the day of the week |
The
cron
daemon will run the
uudemon.poll
script at 20 minutes past the hour and again at 50 minutes past the hour, for
example, at 8:20 a.m. and 8:50 a.m., 9:20 a.m. and 9:50 a.m., and so on.
These times are the defaults. You can change the times at which the
cron
daemon executes
uudemon.poll
to correspond to the times you set up for
uudemon.hour.
You should instruct the
cron
daemon to run
uudemon.poll
about 5 to 10 minutes before running
uudemon.hour.