The netgroup file defines network-wide groups used for permission checking when doing remote mounts, remote logins, and remote shells. For remote mounts, the information in the netgroup file is used to classify machines; for remote logins and remote shells, it is used to classify users. Each line of the netgroup file defines a group and has the following format:
groupname member_1 ... member_n
Each member can be either another group name or a combination of the host name, user name, and domain name in the following format:
(hostname, username, domainname)
Any of the three fields can be empty, in which case a wildcard is assumed. For example, to define a group to which everyone belongs, the following entry could appear in the netgroup file: universal (,,)
Field names that begin with something other than a letter, digit, or underscore (such as ``-'') work in the opposite way. For example: justmachines (analytica,-,suez) justpeople (-,babbage,suez)
The machine analytica belongs to the group justmachines in the domain suez, but no users belong to it. Similarly, the user babbage belongs to the group justpeople in the domain suez, but no machines belong to it.
Network groups are part of the NIS database and are accessed through these files:
/etc/yp/domainname/netgroup.dir /etc/yp/domainname/netgroup.pag /etc/yp/domainname/netgroup.byuser.dir /etc/yp/domainname/netgroup.byuser.pag /etc/yp/domainname/netgroup.byhost.dir /etc/yp/domainname/netgroup.byhost.pag
These files can be created from /etc/netgroup using makedbm(8).
getnetgrent(3), makedbm(8), ypserv(8) delim off