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

NETGROUP(5)						      BSD File Formats Manual						       NETGROUP(5)

NAME

     netgroup -- defines network groups

SYNOPSIS

     netgroup

DESCRIPTION

     The netgroup file specifies ``netgroups'', which are sets of (host, user, domain) tuples that are to be given similar network access.

     Each line in the file consists of a netgroup name followed by a list of the members of the netgroup.  Each member can be either the name of
     another netgroup or a specification of a tuple as follows:

	   (host, user, domain)

     where the host, user, and domain are character string names for the corresponding component.  Any of the comma separated fields may be empty
     to specify a ``wildcard'' value or may consist of the string ``-'' to specify ``no valid value''.	The members of the list may be separated
     by whitespace; the ``'' character may be used at the end of a line to specify line continuation.	The functions specified in getnetgrent(3)
     should normally be used to access the netgroup database.

     If 'files' is specified for the 'netgroup' database in nsswitch.conf(5), (or no 'netgroup' entry is specified), then these functions operate
     on the db(3) version of the netgroup (netgroup.db) file which can be generated using netgroup_mkdb(8).  If 'nis' is specified then the NIS
     maps 'netgroup', 'netgroup.byhost', and 'netgroup.byuser' are used.

     Lines that begin with a # are treated as comments.

FILES

     /etc/netgroup.db  the netgroup database.

SEE ALSO

     getnetgrent(3), exports(5), nsswitch.conf(5), netgroup_mkdb(8)

COMPATIBILITY

     The file format is compatible with that of various vendors, however it appears that not all vendors use an identical format.

BUGS

     The interpretation of access restrictions based on the member tuples of a netgroup is left up to the various network applications.

BSD
								 January 16, 1999							       BSD

Linux and UNIX Man Pages

revnetgroup(8) [osx man page]

Check Out this Related Man Page