IRS.CONF (5)
irs.conf
Information Retrieval System configuration file
SYNOPSIS
DESCRIPTION
The
irs 3
functions are a set of routines in the C library which provide access to
various system maps.
The maps that irs currently controls are the following: passwd, group,
services, protocols, hosts, networks and netgroup.
When a program first calls a function that accesses one of these maps,
the irs configuration file is read,
and the source of each map is determined for the life of the process.
If this file does not exist,
the irs routines default to using local sources for all information,
with the exception of the host and networks maps,
which use the Domain Name System (DNS).
Each record in the file consists of one line.
A record consists of a map-name, an access-method and possibly a (comma
delimited) set of options,
separated by tabs or spaces.
Blank lines, and text between a # and a newline are ignored.
Available maps:
-literal -offset indent
Map name Information in map
========= ==================================
passwd User authentication information
group User group membership information
services Network services directory
protocols Network protocols directory
hosts Network hosts directory
networks Network "network names" directory
netgroup Network "host groups" directory
Available access methods:
-literal -offset indent
Access method Description
============= =================================================
local Use a local file, usually in /etc
dns Use the domain name service (includes hesiod)
nis Use the Sun-compatible Network Information Service
irp Use the IRP daemon on the localhost.
Available options:
-literal -offset indent
Option Description
======== ================================================
continue don't stop searching if you can't find something
merge don't stop searching if you CAN find something
The continue option creates
"union namespaces"
whereby subsequent access methods of the same map type can be tried
if a name cannot be found using earlier access methods.
This can be quite confusing in the case of host names,
since the name to address and address to name mappings can be visibly
asymmetric even though the data used by any given access method is
entirely consistent. This behavior is, therefore, not the default.
The merge option only affects lookups in the groups map.
If set, subsequent access methods will be tried in order to cause
local users to appear in NIS (or other remote) groups in addition
to the local groups.
EXAMPLE
-literal -offset indent
# Get password entries from local file, or failing that, NIS
passwd local continue
passwd nis
# Build group membership from both local file, and NIS.
group local continue,merge
group nis
# Services comes from just the local file.
services local
protocols local
# Hosts comes first from DNS, failing that, the local file
hosts dns continue
hosts local
# Networks comes first from the local file, and failing
# that the, irp daemon
networks local continue
networks irp
netgroup local
NOTES
If a local user needs to be in the local host's
wheel
group but not in every host's
wheel
group, put them in the local host's
/etc/group
wheel
entry and set up the
groups
portion of your
/etc/irs.conf
file as:
-literal -offset indent
group local continue,merge
group nis
NIS takes a long time to time out.
Especially for hosts if you use the
d
option to your server's
ypserv
daemon.
It is important that the
irs.conf
file contain an entry for each map.
If a map is not mentioned in the
irs.conf
file, all queries to that map will fail.
The classic NIS mechanism for specifying union namespaces is to add an entry
to a local map file whose name is ``+''. In IRS, this is done via ``continue''
and/or ``merge'' map options. While this results in a small incompatibility
when local map files are imported from non-IRS systems to IRS systems, there
are compensating advantages in security and configurability.
FILES
SEE ALSO
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