NAME

ypxfr - transfer YP map from a YP server to host

SYNOPSIS

/usr/sbin/ypxfr [ -c ] [ -f ] [ -d ypdomain ] [ -h host ]  [
-s ypdomain ]
      [ -C tid prog server ] mapname

DESCRIPTION

The ypxfr command moves a YP map in the default domain for the local host to the local host by making use of normal YP services. It creates a temporary map in the directory /var/yp/ypdomain (this directory must already exist; ypdomain 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 started without a controlling terminal, and if the log file /var/yp/ypxfr.log exists, it appends all its output to that file. Since ypxfr is most often run from the privileged user's crontab file, or by ypserv, the log file can be used to retain a record of what was attempted, and what the results were. For consistency between servers, ypxfr should be run periodically for every map in the YP data base. Different maps change at different rates: a map may not change for months at a time, for instance, and may therefore be checked only once a day. Some maps may change several times per day. In such a case, you may want to check hourly for updates. A crontab(1) entry can be used to perform periodic updates automatically. Rather than having a separate crontab entry for each map, you can group comands to update several maps in a shell script. Examples (mnemonically named) are in /usr/sbin/yp: ypxfr_1perday, and ypxfr_1perhour. They can serve as reasonable first cuts. Refer to ypfiles(4) and ypserv(1M) for an overview of the YP name service. The following options are available:

-c Do not send a Clear current map request to the local ypserv process. Use this flag if ypserv is not running locally at the time you are running ypxfr. Otherwise, ypxfr complains that it cannot talk to the local ypserv, and the transfer fails.

-f Force the transfer to occur even if the version at the master is not more recent than the local version.

-C tid prog server

This option is only for use by ypserv. When ypserv starts ypxfr, it specifies that ypxfr should call back a yppush process at the host server, registered as program number prog, and waiting for a response to transaction tid.

-d ypdomain

Specify a domain other than the default domain.

-h host

Get the map from host, regardless of what the map says the master is. If host is not specified, ypxfr asks the YP service for the name of the master, and try to get the map from there. host must be a name.

-s ypdomain

Specify a source domain from which to transfer a map that should be the same across domains.

FILES

/var/yp/ypxfr.log     log file

/usr/sbin/yp/ypxfr_1perday

script to run one transfer per day, for use with cron(1M)

/usr/sbin/yp/ypxfr_1perhour

script for hourly transfers of volatile maps

/var/yp/ypdomain      YP domain

/usr/spool/cron/crontabs/root

                      privileged user's crontab file

SEE ALSO

cron(1M), crontab(1), ypserv(1M), yppush(1M), ypfiles(4)