The UUCP Spool Directories and Files

The uucpd daemon supports a UUCP connection over the network. This daemon was developed and introduced later; originally, UUCP was based on the connections other than over the network. Obviously, UUCP had to be adapted to the emerging networking that has become a common way to communicate between computer systems. Sometimes, the daemon is named in.uucpd, like on the Solaris platform. uucpd is invoked by the super server inetd, when a UUCP connection is established via the corresponding well−known UUCP port. The corresponding inetd configuration entry HP−UX 10.20: cat etcinetd.conf | grep uucp uucp stream tcp nowait root usrsbinuucpd uucpd This entry is usually commented out; to activate the uucpd daemon the line must be uncommented and the inetd server recycled. The corresponding UUCP−related port is: cat etcservisces | grep uucp uucp 540tcp uucpd uucp daemon Once invoked, the uucpd daemon prompts for login, requesting the uucico process at the other end the daemon at the remote host that started connection to supply a username and password.

24.5.3 The UUCP Spool Directories and Files

A discussion on UUCP files and directories very quickly focuses on the UUCP spool directory. Despite the fact that UUCP configuration files are located in the etcuucp directory, and UUCP related programs in the usrlibuucp directory, to maintain and administer UUCP properly, understanding of the spool directory is the most important. The contents of the spool directory are constantly changing. In addition to log files, which are always added when a transfer occurs, there are a large number of work files that are dynamically created and deleted during the UUCP communication between UNIX systems. A work file contains the instructions for uucico such as the name of the file to be copied transferred, ownership and permissions, destination, and so on. A work file is created under the name: C.dest_unameAjob_ID where C Stands for a control file, to distinguish from a data file D dest_uname A remote system name, truncated to seven characters A A letter indicating the file processing order letters A to Z, and a to z, or some specific letters depending of the UUCP version job_ID A job identification 6−digit number Each work file can contain up to 20 requests for the file transfer or execution for a given system. For files that are copied to the spool directory uucp −C option, the corresponding data files use the same name with the prefix D. When a remote command execution is requested, an execute 609 One of the major improvements of BNU UUCP was the introduction of the better organized spool directory: usrspooluucp .Admin Administrative files .Corrupt Corrupt files that could not be processed .Log Log files .Old Old log files .Sequence System sequence numbers .Status System status file .Workspace UUCP temporary workspace area .Xqtdir Remote executions Files tofrom the specific systems 610 .system_name2 .system_name3 usrspooluucp.Log uucp Directory of uucp request logs uucico Directory of uucico execution logs uux Directory of uux request logs uuxqt Directory of uuxqt request logs or remote command executions on the local system Probably the biggest administrative problem concerning UUCP is the spool directory cleanup to clean out jobs that have been spooled but not completed successfully. In most UUCP implementations, there are automatic shell scripts to do this cleanup; the only elements to adjust are the frequency those scripts should be running and the lifetime of UUCP work files.

24.6 Configuring a UUCP Link