$ Linux Command

Network

uucico

UUCP file transfer daemon.

uucptransferdaemonserialnetwork

Additional Notes

uucico is the daemon component of the UUCP (Unix-to-Unix Copy) system. It handles the actual file transfer between systems, typically over serial lines or TCP/IP connections. The name stands for "Unix-to-Unix Copy In/Call Out." It is started by the UUCP spooler when there are pending jobs and terminates when transfers are complete.

It can operate in master mode (calling out to initiate transfers) or slave mode (waiting for incoming connections). On modern systems, UUCP is rarely used, having been replaced by email, file sharing protocols, SSH, and rsync. It persists in some embedded or legacy environments.

Syntax

uucico [options]

Parameters

  • options: Flags that change how uucico behaves.
  • target: Optional file, device, interface, user, service, or command target when the command supports one.

Common Options

  • -r role: Set the role (master or slave).
  • -s system: Call the named remote system.
  • -p port: Use the specified port/device.
  • -D: Run in debug mode with verbose output.
  • -x N: Set debug level (N from 0 to 9).
  • -i type: Use the specified interface protocol type.
  • -e: Force the slave role (expect incoming).

Examples

uucico -r master -s remotehost

Call out to remotehost as master and transfer pending jobs.

uucico -r slave

Run as a slave waiting for an incoming connection.

uucico -D -x5

Run in debug mode with verbosity level 5.

Practical Notes

  • UUCP is rarely used on modern systems. Consider SSH-based file transfer or rsync instead.
  • The UUCP suite also includes uucp, uux, uupick, uuto, and uustat.
  • Configuration files reside in /etc/uucp/ (or /etc/uucp/), including sys, port, dial, and dialcodes.
  • UUCP can still be found in some industrial automation and embedded Linux environments.