Data (D.*) files contain the data to be sent to remote systems by the uucp uucico daemon. The full pathname of a data file is a form of the following: /usr/spool/uucp/SystemName/D.SystemNamexxxx###
where the SystemName directory and the SystemName portion of the file name indicate the name of the remote system. The xxxx### notation is the hexadecimal sequence number of the Command (C.*) file associated with that data file; for example, D.venus471afd8.
After a set period of time (specified by the uusched daemon), the uucico daemon transfers the data file to the designated system. It places the original data file in a subdirectory of the uucp spooling directory named /usr/spool/uucp/SystemName, where the SystemName directory is named for the computer that is transmitting the file, and creates a Temporary (TM.*) file to hold the original data file.
After receiving the entire file, the uucp program takes one of three actions: If the file was sent with the uucp command and there were no transfer problems, the program immediately renames the TM.* file with the appropriate data filename, such as D.venus471afd8, and sends it to the specified destination. If the file was sent with the uuto command, the uucp program also renames the temporary data file with the appropriate D.* filename. It then places the data file in the public directory /usr/spool/uucppublic, where the user receives the data file and handles it with one of the uupick command options. If there were transfer problems (such as a failed login or an unavailable device), the temporary data file remains in the spooling subdirectory. The uudemon.cleanu command, a shell script, removes these files automatically at specified intervals, or they can be removed manually.
Daemons: uucico(8), uusched(8), uuxqt
Commands: uucp(1), uupick(1), uuto(1), uux(1), uudemon(4) delim off