revnetgroup(8) [osx man page]

REVNETGROUP(8)						    BSD System Manager's Manual 					    REVNETGROUP(8)

NAME

     revnetgroup -- generate reverse netgroup data

SYNOPSIS

     revnetgroup -u | -h [-f netgroup_file]

DESCRIPTION

     The revnetgroup utility processes the contents of a file in netgroup(5) format into what is called reverse netgroup form.	That is, where the
     original file shows netgroup memberships in terms of which members reside in a particular group, the reverse netgroup format specifies what
     groups are associated with a particular member.  This information is used to generate the netgroup.byuser and netgroup.byhosts NIS maps.
     These reverse netgroup maps are used to help speed up netgroup lookups, particularly for the innetgr() library function.

     For example, the standard /etc/netgroup file may list a netgroup and a list of its members.  Here, the netgroup is considered the key and the
     member names are the data.  By contrast, the reverse netgroup.byusers database lists each unique member as the key and the netgroups to which
     the members belong become the data.  Separate databases are created to hold information pertaining to users and hosts; this allows netgroup
     username lookups and netgroup hostname lookups to be performed using independent keyspaces.

     By constructing these reverse netgroup databases (and the corresponding NIS maps) in advance, the getnetgrent(3) library functions are spared
     from having to work out the dependencies themselves on the fly.  This is important on networks with large numbers of users and hosts, since
     it can take a considerable amount of time to process very large netgroup databases.

     The revnetgroup utility prints its results on the standard output.  It is usually called only by /var/yp/Makefile when rebuilding the NIS
     netgroup maps.

OPTIONS

     The revnetgroup utility supports the following options:

     -u      Generate netgroup.byuser output; only username information in the original netgroup file is processed.

     -h      Generate netgroup.byhost output; only hostname information in the original netgroup file is processed.  (Note at least one of the -u
	     or -h flags must be specified.)

     [-f netgroup_file]
	     The revnetgroup utility uses /etc/netgroup as its default input file.  The -f flag allows the user to specify an alternate input
	     file.  Specifying ``-'' as the input file causes revnetgroup to read from the standard input.

FILES

     /var/yp/Makefile  the Makefile that calls yp_mkdb and revnetgroup to build the NIS databases
     /etc/netgroup     the default netgroup database file.  This file is most often found only on the NIS master server

SEE ALSO

     getnetgrent(3), netgroup(5), yp(8), yp_mkdb(8)

AUTHORS

     Bill Paul <wpaul@ctr.columbia.edu>

BSD
								 October 24, 1995							       BSD

Check Out this Related Man Page

getnetgrent(3)						     Library Functions Manual						    getnetgrent(3)

NAME

       getnetgrent, setnetgrent, endnetgrent, innetgr - get network group entry

SYNOPSIS

       innetgr(netgroup, machine, user, domain)
       char *netgroup, *machine, *user, *domain;
       setnetgrent(netgroup)
       char *netgroup
       endnetgrent()
       getnetgrent(machinep, userp, domainp)
       char **machinep, **userp, **domainp;

DESCRIPTION

       The innetgr routine accesses the netgroup file and checks to see if the specified input parameters match an entry in the file.  The routine
       returns 1 if it matches an entry, or 0 if it does not.  Any of the three strings; machine, user, or domain can be NULL, which signifies any
       string in that position is valid.

       The getnetgrent routine returns the next member of a network group.  After the call, machinep will contain a pointer to a string containing
       the name of the machine part of the network group member, and similarly for userp and domainp.  If machinep, userp or domainp  is  returned
       as  a  NULL  pointer,  it signifies any string is valid.  The getnetgrent routine allocates space for the name by using the malloc routine.
       This space is released when an endnetgrent call is made.  The getnetgrent routine returns 1 if it succeeds in obtaining another	member	of
       the network group, or 0 if it reaches the end of the group.

       The  setnetgrent  routine  establishes the network group from which getnetgrent will obtain members, and also restarts calls to getnetgrent
       from the beginning of the list.	If the previous setnetgrent call was to a different network group, an endnetgrent call is implied.

       The endnetgrent routine releases the space allocated during the getnetgrent calls.

       Note that the netgroup file is distributed by NIS and exists in its original, readable form on the  NIS	master	server	only.	NIS  slave
       servers distribute copies of the netgroup maps created from the original on the master.

FILES

       /var/yp/src/netgroup
       /var/yp/domain/netgroup
       /var/yp/domain/netgroup.byuser
       /var/yp/domain/netgroup.byhost
       delim off

																    getnetgrent(3)

Linux and UNIX Man Pages

revnetgroup(8) [osx man page]

Check Out this Related Man Page