NAME
setnetgrent, endnetgrent, getnetgrent, getnetgrent_r, innetgr - handle
network group entries
SYNOPSIS
#include <netdb.h>
int setnetgrent(const char *netgroup);
void endnetgrent(void);
int getnetgrent(char **host, char **user, char **domain);
int getnetgrent_r(char **host, char **user,
char **domain, char *buf, int buflen);
int innetgr(const char *netgroup, const char *host,
const char *user, const char *domain);
Feature Test Macro Requirements for glibc (see feature_test_macros(7)):
setnetgrent(), endnetgrent(), getnetgrent(), getnetgrent_r(),
innetgr(): _BSD_SOURCE || _SVID_SOURCE
DESCRIPTION
The netgroup is a SunOS invention. A netgroup database is a list of
string triples (hostname, username, domainname) or other netgroup
names. Any of the elements in a triple can be empty, which means that
anything matches. The functions described here allow access to the
netgroup databases. The file /etc/nsswitch.conf defines what database
is searched.
The setnetgrent() call defines the netgroup that will be searched by
subsequent getnetgrent() calls. The getnetgrent() function retrieves
the next netgroup entry, and returns pointers in host, user, domain. A
NULL pointer means that the corresponding entry matches any string.
The pointers are valid only as long as there is no call to other
netgroup-related functions. To avoid this problem you can use the GNU
function getnetgrent_r() that stores the strings in the supplied
buffer. To free all allocated buffers use endnetgrent().
In most cases you only want to check if the triplet
(hostname,username,domainname) is a member of a netgroup. The function
innetgr() can be used for this without calling the above three
functions. Again, a NULL pointer is a wildcard and matches any string.
The function is thread-safe.
RETURN VALUE
These functions return 1 on success and 0 for failure.
FILES
/etc/netgroup
/etc/nsswitch.conf
CONFORMING TO
These functions are not in POSIX.1-2001, but setnetgrent(),
endnetgrent(), getnetgrent(), and innetgr() are available on most Unix
systems. getnetgrent_r() is not widely available on other systems.
NOTES
In the BSD implementation, setnetgrent() returns void.
SEE ALSO
sethostent(3), setprotoent(3), setservent(3)
COLOPHON
This page is part of release 3.24 of the Linux man-pages project. A
description of the project, and information about reporting bugs, can
be found at http://www.kernel.org/doc/man-pages/.