UUCICO(8) System Manager's Manual UUCICO(8)
uucico, uucpd - transfer files queued by uucp or uux
/usr/sbin/uucico [ -dspooldir ] [ -ggrade ] [ -rrole ] [ -R ] [ -ssys‐
tem ] [ -xdebug ] [ -L ] [ -tturnaround ]
Uucico performs the actual work involved in transferring files between
systems. Uucp(1) and uux(1) merely queue requests for data transfer
which uucico processes.
The following options are available.
Use spooldir as the spool directory. The default is
-ggrade Only send jobs of grade grade or higher this transfer. The
grade of a job is specified when the job is queued by uucp or
-rrole role is either 1 or 0; it indicates whether uucico is to start
up in master or slave role, respectively. 1 is used when run‐
ning uucico by hand or from cron(8). 0 is used when another
system calls the local system. Slave role is the default.
-R Reverse roles. When used with the -r1 option, this tells the
remote system to begin sending its jobs first, instead of wait‐
ing for the local machine to finish.
Call only system system. If -s is not specified, and -r1 is
specified, uucico will attempt to call all systems for which
there is work. If -s is specified, a call will be made even if
there is no work for that system. This is useful for polling.
-xdebug Turn on debugging at level debug. Level 5 is a good start when
trying to find out why a call failed. Level 9 is very detailed.
Level 99 is absurdly verbose. If role is 1 (master), output is
normally written to the standard message output stderr. If
stderr is unavailable, output is written to
/usr/spool/uucp/AUDIT/system. When role is 0 (slave), debug‐
ging output is always written to the AUDIT file.
-L Only call ``local'' sites. A site is considered local if the
device-type field in L.sys is one of LOCAL, DIR or TCP.
Use turnaround as the line turnaround time (in minutes) instead
of the default 30. If turnaround is missing or 0, line turn‐
around will be disabled. After uucico has been running in
slave role for turnaround minutes, it will attempt to run in
master role by negotiating with the remote machine. In earlier
versions of uucico, a transfer of many large files in one
direction would hold up mail going in the other direction.
With the turnaround code working, the message flow will be more
bidirectional in the short term. This option only works with
newer uucico's and is ignored by older ones.
If uucico receives a SIGFPE (see kill(1)), it will toggle the debugging
on or off.
Uucpd is the server for supporting uucp connections over networks.
Uucpd listens for service requests at the port indicated in the
``uucp'' service specification; see services(5). The server provides
login name and password authentication before starting up uucico for
the rest of the transaction.
Uucico is commonly used either of two ways: as a daemon run periodi‐
cally by cron(8) to call out to remote systems, and as a ``shell'' for
remote systems who call in. For calling out periodically, a typical
line in crontab would be:
0 * * * * /usr/sbin/uucico -r1
This will run uucico every hour in master role. For each system that
has transfer requests queued, uucico calls the system, logs in, and
executes the transfers. The file L.sys(5) is consulted for information
about how to log in, while L-devices(5) specifies available lines and
modems for calling.
For remote systems to dial in, an entry in the passwd(5) file must be
created, with a login ``shell'' of uucico. For example:
The UID for UUCP remote logins is not critical, so long as it differs
from the UUCP Administrative login. The latter owns the UUCP files,
and assigning this UID to a remote login would be an extreme security
/etc/uucp/ UUCP internal files
/etc/uucp/L-devices Local device descriptions
/etc/uucp/L-dialcodes Phone numbers and prefixes
/etc/uucp/L.aliases Hostname aliases
/etc/uucp/L.cmds Remote command permissions list
/etc/uucp/L.sys Host connection specifications
/etc/uucp/USERFILE Remote directory tree permissions list
/usr/spool/uucp/ Spool directory
/usr/spool/uucp/AUDIT/* Debugging audit trails
/usr/spool/uucp/C./ Control files directory
/usr/spool/uucp/D./ Incoming data file directory
/usr/spool/uucp/D.hostname/ Outgoing data file directory
/usr/spool/uucp/D.hostnameX/ Outgoing execution file directory
/usr/spool/uucp/CORRUPT/ Place for corrupted C. and D. files
/usr/spool/uucp/ERRLOG UUCP internal error log
/usr/spool/uucp/LOGFILE UUCP system activity log
/usr/spool/uucp/LCK/LCK..* Device lock files
/usr/spool/uucp/SYSLOG File transfer statistics log
/usr/spool/uucp/STST/* System status files
/usr/spool/uucp/TM./ File transfer temp directory
/usr/spool/uucp/X./ Incoming execution file directory
/usr/spool/uucppublic Public access directory
uucp(1), uuq(1), uux(1), L-devices(5), L-dialcodes(5), L.aliases(5),
L.cmds(5), L.sys(5), uuclean(8), uupoll(8), uusnap(8), uuxqt(8)
D. A. Nowitz and M. E. Lesk, A Dial-Up Network of UNIX Systems.
D. A. Nowitz, Uucp Implementation Description.
4.3 Berkeley Distribution October 23, 1996 UUCICO(8)