ypxfr moves a Network Information Service (NIS) map in the default domain for the local host to the local host by making use of normal NIS services. It creates a temporary map in the directory /var/yp/domain (this directory must already exist; domain is the default domain for the local host), fills it by enumerating the map's entries, fetches the map parameters (master and order number), and loads them. It then deletes any old versions of the map and moves the temporary map to the real mapname.
If run interactively, ypxfr writes its output to the terminal. However, if it is invoked without a controlling terminal, and if the log file /var/yp/ypxfr.log exists, it will append all its output to that file. Since ypxfr is most often run from the super-user's crontab file, or by ypserv, you can use the log file to retain a record of what was attempted, and what the results were.
If issecure.3 is TRUE, ypxfr requires that ypserv on the host be running as root. If the map being transferred is a secure map, ypxfr sets the permissions on the map to 0600.
For consistency between servers, ypxfr should be run periodically for every map in the NIS data base. Different maps change at different rates: the services.byname map may not change for months at a time, for instance, and may therefore be checked only once a day (in the wee hours). You may know that mail.aliases or hosts.byname changes several times per day. In such a case, you may want to check hourly for updates. A crontab.5 entry can be used to perform periodic updates automatically. Rather than having a separate crontab entry for each map, you can group commands to update several maps in a shell script. Examples (mnemonically named) are in /usr/etc/yp: ypxfr_1perday, ypxfr_2perday, and ypxfr_1perhour. They can serve as reasonable first cuts.
Refer to ypfiles.5 and ypserv.8 for an overview of the NIS service.
YP Protocol Specification, in [a manual with the abbreviation NETP]
The Network Information Service (NIS) was formerly known as Sun Yellow Pages (YP). The functionality of the two remains the same; only the name has changed. The name Yellow Pages is a registered trademark in the United Kingdom of British Telecommunications plc, and may not be used without permission.
Created by unroff & hp-tools. © by Hans-Peter Bischof. All Rights Reserved (1997).
Last modified 21/April/97