From - Tue Apr  8 18:17:58 1997
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From: nmw@ion.le.ac.uk (Nigel Wade)
Newsgroups: comp.sys.sgi.admin
Subject: Re: how to use NIS netgroups in scripts
Date: 7 Apr 1997 12:32:59 GMT
Organization: University of Leicester, UK
Lines: 96
Message-ID: <5iaphr$4qk@falcon.le.ac.uk>
References: <3345504F.6201@execpc.com>
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In article <3345504F.6201@execpc.com>,
	Jonathan Detert <metco@execpc.com> writes:
>Hello SGI system admins,
>
>i made netgroups to simplify .rhost maintenance, and to simplify script
>writing - e.g. i wanted to be able to say, "for all irix hosts; do", and
>i thought that using a netgroup would be a decent vehicle.  I'm finding
>that it ain't such a decent vehicle:
>
>	1st: i have to strip off the parantheses, and username;
>	2nd: ypmatch doesn't recursively expand nested netgroup names.
>
>Does anyone have a better idea for how to use NIS as the definitive
>source of host names of a certain character (i.e. all irix hosts)?
>
>Thanks, and 
>-- 
>Happy Landings,
>
>	Jon Detert	metco@execpc.com	414.783.8527


IMHO netgroups are the best. 

I have appended a program which lists each entry in a netgroup.  

The -h/-f flags are because I have two entries for each machine, one with 
just the hostname, and the other with the FQDN; the flag allows me to select 
which I want (by default it would list both).

If you build an executable called netgroup, you can have commands like,

for host in `netgroup -h <groupname>`; do rsh $host "commands"; done


Hope this helps.

-- 
-----------------------------------------------------------
Nigel Wade, System Administrator, Space Plasma Physics Group,
            University of Leicester, Leicester, LE1 7RH, UK 
E-mail :    nmw@ion.le.ac.uk 
Phone :     +44 (0)116 2523568, Fax : +44 (0)116 2523555


<<--- code for netgroup.c  -->>

#include <stdio.h>
#include <stdlib.h>
#include <getopt.h>
#include <string.h>

void usage(void) 
{ 
fprintf(stderr,"Usage: [-h] [-f] netgroup groupname\n"); 
exit(1);
}


main(int argc, char **argv)
{
    char *machine,
	 *user,
	 *domain;

    int  host_part = 0;
    int  DNS_part = 0;

    int c;

    while( (c = getopt(argc, argv, "hf")) != -1 ) {
	switch(c) {
	    case 'h' : host_part = 1; break;
	    case 'f' : DNS_part = 1; break;
	}
    }
    if ( host_part == 0 && DNS_part == 0 ) {
	host_part = 1;
	DNS_part = 1;
    }

    if ( argc-optind != 1 )
	usage();

    setnetgrent(argv[optind]);
    while( getnetgrent(&machine, &user, &domain) == 1 ) {
	if ( strchr(machine, '.') != NULL && DNS_part == 1 )
	    fprintf(stdout, "%s ", machine);
	if ( strchr(machine, '.') == NULL && host_part == 1 )
	    fprintf(stdout, "%s ", machine);
    }

    endnetgrent();
    fprintf(stdout, "\n");
}