ypxfr(NADM)                     19 June 1992                     ypxfr(NADM)


 Name

    ypxfr - transfer an NIS map from an NIS server to here

 Syntax

    ypxfr [ -b ] [ -S ] [ -f ] [ -h host ] [ -s domain ] [ -d domain ] [ -c ]
    [ -C tid prog ipadd port ] mapname

 Description

    ypxfr moves an NIS map to the local host by making use of normal NIS ser-
    vices.  It creates a temporary map in the directory /etc/yp/domain (which
    must already exist), fills it by enumerating the map's entries, fetches
    the map parameters (master and order numbers) and loads them.  It then
    deletes any old versions of the map and moves the temporary map to the
    real mapname.

    If ypxfr is run interactively, it writes its output to the terminal.
    However, if it is invoked without a controlling terminal and the log file
    /usr/adm/nislog exists, it will append all its output to that file.
    Since ypxfr is most often run from /usr/lib/crontab, or by ypserv, you
    can use the log file to retain a record of what was attempted and what
    the results were.

    If the -S secure option is set, ypxfr requires that ypserv on the host be
    running as root and using a reserved port.  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 database. Different maps change at different rates:
    for example, the services.byname map may not change for months at a time
    and may therefore be checked only once a day in the early hours.  Con-
    versely, you may know that mail.aliases or hosts.byname may change
    several times per day.  In such a case, you may want to check for updates
    on an hourly basis.  A crontab(C) 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 /etc/yp:  ypxfr1pdy,
    ypxfr2pdy, and ypxfr1phr.  They can serve as reasonable first cuts.

    Refer to ypfiles(NF) and ypserv(NADM) for an overview of the network in-
    formation service.

    After transferring a map, ypxfr checks for the existence of a file with
    the same name as the map in the directory /etc/yp/map2ascii.  If such a
    file exists, it is run by forking a shell to execute it.  These files
    must be shell scripts.  They are intended to convert the contents of the
    map with the same name to an ASCII file in the proper place, usually
    /etc.  An example of this is the passwd.nam script. This script is used
    to convert the contents of the passwd.byname map to a flat ASCII file,
    which is installed as /etc/passwd.  Thus, the utilities on a system may
    be able to utilize network-wide files such as the passwd or host files
    without being modified or recompiled to use the NIS versions of the
    passwd file or host table access routines.  See map2ascii(NADM) for more
    details on this.

 Options


    -b               preserve the resolver flag in the map during the
                     transfer

    -S               only use NIS servers running as root and using a
                     reserved port

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

    -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 will complain that it cannot talk to the local
                     ypserv and the transfer will fail.

    -h host          get the map from host, regardless of what the map says
                     the master is.  If host is not specified, ypxfr will ask
                     the NIS service for the name of the master and then try
                     to get the map from there.  host may be a name or an
                     internet address in the form a.b.c.d.

    -s domain        specify a source domain from which to transfer a map
                     that should be the same across domains (such as the
                     services.byname map)

    -d domain        specify a domain other than the default domain

    -C tid prog ipadd port
                     This option is only for use by ypserv.  When ypserv
                     invokes ypxfr, it specifies that ypxfr should call back
                     a yppush process at the host with IP address ipaddr,
                     registered as program number prog, listening on port
                     port, and waiting for a response to transaction tid.

 Files

    /usr/adm/nislog, /etc/yp/ypxfr1pdy, /etc/yp/ypxfr2pdy, /etc/yp/ypxfr1phr,
    /etc/yp/YP_MAP_X_LATE, /usr/lib/crontab

 See also

    ypfiles(NF), ypserv(NADM), yppush(NADM), ypmapxlate(NF), map2ascii(NADM)