GETNETGRENT(3) Library Functions Manual GETNETGRENT(3)

getnetgrent, innetgr, setnetgrent, endnetgrent — netgroup database operations

Standard C Library (libc, -lc)

#include <netdb.h>

int
getnetgrent(char **host, char **user, char **domain);

int
innetgr(const char *netgroup, const char *host, const char *user, const char *domain);

void
setnetgrent(const char *netgroup);

void
endnetgrent(void);

These functions operate on the netgroup database file /etc/netgroup which is described in netgroup(5). The database defines a set of netgroups, each made up of one or more triples:

(host, user, domain)
that defines a combination of host, user and domain. Any of the three fields may be specified as ``wildcards'' that match any string.

The function () sets the three pointer arguments to the strings of the next member of the current netgroup. If any of the string pointers are (char *)0 that field is considered a wildcard.

The functions () and () set the current netgroup and terminate the current netgroup respectively. If setnetgrent() is called with a different netgroup than the previous call, an implicit endnetgrent() is implied. The setnetgrent() function also sets the offset to the first member of the netgroup.

The function () searches for a match of all fields within the specified group. If any of the , , or domain arguments are (char *)0 those fields will match any string value in the netgroup member.

The function getnetgrent() returns 0 for ``no more netgroup members'' and 1 otherwise. The function innetgr() returns 1 for a successful match and 0 otherwise. The functions setnetgrent() and endnetgrent() have no return value.

/etc/netgroup
netgroup database file

The netgroup members have three string fields to maintain compatibility with other vendor implementations, however it is not obvious what use the domain string has within BSD.

netgroup(5)

The function getnetgrent() returns pointers to dynamically allocated data areas that are freed when the function endnetgrent() is called.

June 4, 1993 macOS 15.2