Linux nischttl command

Updated: 04/26/2017 by Computer Hope

About nischttl

On Solaris, the nischttl command changes the time-to-live value of an NIS+ object.

Description

nischttl changes the time-to-live value ("ttl") of the NIS+ objects or entries specified by name to time. Entries are specified using indexed names (see nismatch).

The time-to-live value is used by object caches to expire objects within the cache. When an object is read into the cache, this value is added to the current time in seconds yielding the time when the cached object would expire. The object may be returned from the cache until the current time is earlier than the calculated expiration time. When the expiration time has been reached, the object will be flushed from the cache.

The time-to-live time may be specified in seconds or in days, hours, minutes, seconds format. The latter format uses a suffix letter of d, h, m, or s to identify the units of time. See the examples below for usage.

The command will fail if the master NIS+ server is not running.

Setting a high ttl value allows objects to stay persistent in caches for a longer period of time and can improve performance. However, when an object changes, in the worst case, the number of seconds in this attribute must pass before that change is visible to all clients. Setting a ttl value of 0 means that the object should not be cached at all.

A high ttl value is a week, a low value is less than a minute. Password entries should have ttl values of about 12 hours (easily allows one password change per day), entries in the RPC table can have ttl values of several weeks (this information is effectively unchanging).

Only directory and group objects are cached.

nischttl syntax

nischttl [-AfLP] time name...

Options

-A Modify all tables in the concatenation path that match the search criterion specified in name. This option implies the -P switch.
-f Force the operation and fail silently if it does not succeed.
-L Follow links and change the time-to-live of the linked object or entries rather than the time-to-live of the link itself.
-P Follow the concatenation path within a named table. This option only makes sense when either name is an indexed name or the -L switch is also specified and the named object is a link pointing to entries.

Environment

If the NIS_PATH environment variable is set, and the NIS+ name is not fully qualified, each directory specified will be searched until the object is found. See nisdefaults.

nischttl examples

nischttl 1d12h object

Set the time-to-live of NIS+ object object to 36 hours (1 day, 12 hours).

nischttl 129600 object

Set the time-to-live of NIS+ object object to 129600 seconds (one and a half days).

nischttl 1h30m '[uid=99],passwd.org_dir'

Change the time-to-live of a password entry to 90 minutes.

nischmod — Change access rights on an NIS+ object.
nischown — Change the owner of an NIS+ object on a system running Solaris.
nisdefaults — Display NIS+ default values.
nismatch — Utilities for searching NIS+ tables.