You can use different Systems files so that requests for login services can be made to other addresses than UUCP services.
With different Dialers files you can use different handshaking for cu and uucp. Multiple Systems, Dialers, and Devices files are useful if any one file becomes too large.
An active Sysfiles file is not included in the distribution. Instead a Sysfiles.eg file is included, which contains comments and commented examples of how such a file can be used. This is done because UUCP runs faster if it does not have to read this file.
Each entry in Sysfiles must include a service statement which defines the files to be assigned for a given service. service takes as its argument one of:
The following filetypes may be set:
devices, dialers, and systems take a list of alternative files to be searched as their argument list. Each file in the list is separated from the next by a colon (:). No spaces are allowed in the list. The files should appear in the order that they are to be searched when an entry is being sought. The pathname of each file is assumed to be given relative to the /usr/lib/uucp directory, unless a full path is given. A backslash-carriage return (\<Return>) can be used to continue an entry onto the next line.
When different Systems files are defined for uucico
and cu services, your machine will store two different lists of
Systems.
You can print the uucico list using the uuname command
or the cu list using the uuname -c command.
service=uucico:cu systems=Systems:Local_SystemsIf this is in /usr/lib/uucp/Sysfiles, then both uucico and cu will first look in /usr/lib/uucp/Systems. If the system they are trying to call does not have an entry in that file, or if the entries in the file fail, then they will look in /usr/lib/uucp/Local_Systems.
Different Systems and Dialers files may be used to separate uucico and cu-specific information. Common information is retained in the Systems and Dialers files.
This next example uses the same systems files for uucico and cu, but has split the Systems file into local, company-wide, and global files.service=uucico systems=Systems.cico:Systems \ dialers=Dialers.cico:Dialers service=cu systems=Systems.cu:Systems \ dialers=Dialers.cu:Dialers
service=uucico systems=Systems.local:Systems.company:Systems service=cu systems=Systems.local:Systems.company:Systems