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uucico(8) System Manager's Manual uucico(8)


uucico - UUCP file transfer daemon


uucico [ options ]


The uucico daemon processes file transfer requests queued by uucp (1) and uux (1). It is started when uucp or uux is run (unless they are given the -r option). It is also typically started periodically using entries in the crontab table(s).

When invoked with -r1, --master, -s, --system, or -S, the daemon will place a call to a remote system, running in master mode. Otherwise the daemon will start in slave mode, accepting a call from a remote system. Typically a special login name will be set up for UUCP which automatically invokes uucico when a call is made.

When uucico terminates, it invokes the uuxqt (8) daemon, unless the -q or --nouuxqt option is given; uuxqt (8) executes any work orders created by uux (1) on a remote system, and any work orders created locally which have received remote files for which they were waiting.

If a call fails, uucico will normally refuse to retry the call until a certain (configurable) amount of time has passed. This may be overridden by the -f, --force, or -S option.

The -l, --prompt, -e, or --loop options may be used to force uucico to produce its own prompts of "login: " and "Password:". When another daemon calls in, it will see these prompts and log in as usual. The login name and password will normally be checked against a separate list kept specially for uucico rather than the /etc/passwd file; it is possible on some systems to direct uucico to use the /etc/passwd file. The -l or --prompt option will prompt once and then exit; in this mode the UUCP administrator or the superuser may use the -u or --login option to force a login name, in which case uucico will not prompt for one. The -e or --loop option will prompt again after the first session is over; in this mode uucico will permanently control a port.

If uucico receives a SIGQUIT, SIGTERM or SIGPIPE signal, it will cleanly abort any current conversation with a remote system and exit. If it receives a SIGHUP signal it will abort any current conversation, but will continue to place calls to (if invoked with -r1 or --master) and accept calls from (if invoked with -e or --loop) other systems. If it receives a SIGINT signal it will finish the current conversation, but will not place or accept any more calls.


The following options may be given to uucico.

Start in master mode (call out to a system); implied by -s, --system, or -S. If no system is specified, call any system for which work is waiting to be done.
Start in slave mode. This is the default.
Call the named system.
Call the named system, ignoring any required wait. This is equivalent to -s system -f.
Ignore any required wait for any systems to be called.
Prompt for login name and password using "login: " and "Password:". This allows uucico to be easily run from inetd (8). The login name and password are checked against the UUCP password file, which probably has no connection to the file /etc/passwd. The --login option may be used to force a login name, in which cause uucico will only prompt for a password.
Specify a port to call out on or to listen to.
Enter endless loop of login/password prompts and slave mode daemon execution. The program will not stop by itself; you must use kill (1) to shut it down.
After calling out (to a particular system when -s, --system, or -S is specified, or to all systems which have work when just -r1 or --master is specified), begin an endless loop as with --loop.
Do not start the uuxqt (8) daemon when finished.
If no calls are permitted at this time, then don't make the call, but also do not put an error message in the log file and do not update the system status (as reported by uustat (1)). This can be convenient for automated polling scripts, which may want to simply attempt to call every system rather than worry about which particular systems may be called at the moment. This option also suppresses the log message indicating that there is no work to be done.
Only call the system named by -s, --system or -S if there is work for that system.
Do not detach from the controlling terminal. Normally uucico detaches from the terminal before each call out to another system and before invoking uuxqt. This option prevents this.
Set the login name to use instead of that of the invoking user. This option may only be used by the UUCP administrator or the superuser. If used with --prompt, this will cause uucico to prompt only for the password, not the login name.
If a call fails after the remote system is reached, try the next alternate rather than simply exiting.
Set the type of port to use when using standard input. The only support port type is TLI, and this is only available on machines which support the TLI networking interface. Specifying -iTLI causes uucico to use TLI calls to perform I/O.
Turn on particular debugging types. The following types are recognized: abnormal, chat, handshake, uucp-proto, proto, port, config, spooldir, execute, incoming, outgoing.

Multiple types may be given, separated by commas, and the --debug option may appear multiple times. A number may also be given, which will turn on that many types from the foregoing list; for example, --debug 2 is equivalent to --debug abnormal,chat.

The debugging output is sent to the debugging file, which may be printed using uulog -D.

Set configuration file to use. This option may not be available, depending upon how uucico was compiled.
Report version information and exit.
Print a help message and exit.


kill(1), uucp(1), uux(1), uustat(1), uuxqt(8)


Ian Lance Taylor <>

Taylor UUCP 1.07