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Unix-to-Unix Copy

(also UUCP)

Unix-to-Unix Copy definition

Unix-to-Unix Copy (UUCP) is a suite of legacy protocols and programs used in the transmission of files and email between computers. UUCP was originally developed in the 1970s for Unix, but was later adapted to other operating systems, including DOS, OS/2, and Classic Mac OS.

UUCP has largely been replaced by the TCP/IP protocol suite in modern systems. However, several UUCP principles, such as batch processing and the use of configuration files, have had a major impact on the development of later networking technologies.

See also: unix box, usenet, data transfer, batch processing, configuration file

How UUCP works

Before any file transmission can take place, the participating systems need to be defined in the UUCP “Systems” file (specifying information such as their phone number and login credentials) and access permissions must be configured in the “Permissions” file.

Once configured, the sending system uses the uucico (Unix-to-Unix Copy) daemon to establish a dial-up connection to the receiving system and exchange information about the files to be transferred.

The uux command (which allows the execution of commands on the remote system) initiates the file transfer. UUCP can transfer multiple files in a single session using batch processing. After the transfer is complete, the daemon terminates the connection and the systems return to an idle state.