Originální popis anglicky:
setnetgrent, endnetgrent, getnetgrent, getnetgrent_r, innetgr - handle network
group entries
Návod, kniha: Linux Programmer's Manual
#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);
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.
/etc/netgroup
/etc/nsswitch.conf
These functions return 1 on success and 0 for failure.
In the BSD implementation,
setnetgrent() returns void.
sethostent(3),
setservent(3),
setprotoent(3)
