Linux and UNIX Man Pages

Linux & Unix Commands - Search Man Pages

revnetgroup(8) [osx man page]

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

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 <> BSD
October 24, 1995 BSD

Check Out this Related Man Page

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

netgroup -- defines network groups SYNOPSIS
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
Man Page