VIS(4-SVR4) RISC/os Reference Manual VIS(4-SVR4)
NAME
vis - virtual information service
DESCRIPTION
vis, the MIPS Virtual Information Service (VIS), provides
the ability to use multiple information provider services on
a single host. Currently, VIS supports the following ser-
vices:
nis SUN's Network Information Service (formerly
known as YP or Yellow Pages)
dns the DARPA Domain Name Service
files the standard UNIX information files
The file /etc/vis.conf controls the system wide behavior of
those routines which provide information to user programs.
Examples of such routines are getprotobyname(3) and gethost-
byaddr(3). Such routines are classified according to the
type of information they provide; currently supported
classes are:
host the class of information returned by the
gethostbyname(3N) routines
passwd the class of information returned by the
getpwent(3) routines
group the class of information returned by the get-
grent(3) routines
net the class of information returned by the
getnetent(3N) routines
netgroup the class of information returned by the
getnetgrent(3N) routines
services the class of information returned by the
getservent(3N) routines
proto the class of information returned by the
getprotoent(3N) routines
For each class, /etc/vis.conf may contain an ordered list of
information services. The syntax of the file is:
class: service service service ...
One or more service entries may be provided for each class.
The information routine will try each service in the list in
the order specified for that class.
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VIS(4-SVR4) RISC/os Reference Manual VIS(4-SVR4)
If the file /etc/vis.conf does not exist, or if no entry
exists for the requested information class, the routine will
use the files service as the default.
If the environment variable VISSERVICES is set to the name
of a valid file with the same syntax as /etc/vis.conf, that
file will be used instead. This allows for user or even
program specific information service behavior.
EXAMPLE
A line in /etc/vis.conf of the form
host: files dns
forces the gethostbyname(3) routines to first look in the
file /etc/hosts for information about the requested host.
If a match is found, the information from /etc/hosts is
returned. If a match was not found, or if the files infor-
mation service could not respond to requests of class host,
the Domain Name Service is queried. If a match is found by
the Domain Name Service, the requested information will be
returned, otherwise a failure indication appropriate for the
calling routine is indicated.
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