SETNETGRENT(3)                                      Linux Programmer's Manual                                     SETNETGRENT(3)



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 3.25 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/.



GNU                                                        2007-07-26                                             SETNETGRENT(3)