getnetgrent(3C) 					   Standard C Library Functions 					   getnetgrent(3C)

NAME

       getnetgrent, getnetgrent_r, setnetgrent, endnetgrent, innetgr - get network group entry

SYNOPSIS

       #include <netdb.h>

       int getnetgrent(char **machinep, char **userp, char **domainp);

       int getnetgrent_r(char **machinep, char **userp, char **domainp, char *buffer, intbuflen);

       int setnetgrent(const char *netgroup);

       int endnetgrent(void);

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

DESCRIPTION

       These  functions  are  used  to test membership in and enumerate members of ``netgroup'' network groups defined in a system database.  Net-
       groups are sets of (machine,user,domain) triples (see netgroup(4)).

       These functions consult the source specified for netgroup in the /etc/nsswitch.conf file (see nsswitch.conf(4)).

       The function innetgr() returns  1 if there is a netgroup netgroup that contains the specified machine, user, domain  triple  as	a  member;
       otherwise it returns
	0.  Any  of the supplied pointers machine, user, and domain may be NULL, signifying a "wild card" that matches all values in that position
       of the triple.

       The innetgr() function is safe for use in single-threaded and multithreaded applications.

       The functions setnetgrent(), getnetgrent(), and endnetgrent() are used to enumerate the members of a given network group.

       The function setnetgrent() establishes the network group specified in the parameter netgroup as the current group whose members are  to	be
       enumerated.

       Successive  calls  to  the  function  getnetgrent() will enumerate the members of the group established by calling setnetgrent(); each call
       returns	1 if it succeeds in obtaining another member of the network group, or  0 if there are no further members of the group.

       When calling either getnetgrent() or getnetgrent_r(), addresses of the three character pointers are used as arguments, for example:

       char *mp, *up, *dp;
       getnetgrent(&mp, &up, &dp);

       Upon successful return from  getnetgrent(), the pointer mp points to a string containing the name of the machine part of the member triple,
       up points to a string containing the user name and dp points to a string containing the domain name. If the pointer returned for mp, up, or
       dp is NULL, it signifies that the element of the netgroup contains wild card specifier in that position of the triple.

       The pointers returned by getnetgrent() point into a buffer allocated by setnetgrent() that is reused by each call. This space  is  released
       when  an  endnetgrent()	call  is made, and should not be released by the caller. This implementation is not safe for use in multi-threaded
       applications.

       The function getnetgrent_r() is similar to getnetgrent() function, but it uses a buffer supplied by the caller  for  the  space	needed	to
       store  the  results.   The parameter buffer should be a pointer to a buffer allocated by the caller and the length of this buffer should be
       specified by the parameter buflen. The buffer must be large enough to hold the data associated with the triple. The  getnetgrent_r()  func-
       tion is safe for use both in single-threaded and multi-threaded applications.

       The  function  endnetgrent()  frees  the space allocated by the previous setnetgrent() call.  The equivalent of an endnetgrent() implicitly
       performed whenever a  setnetgrent() call is made to a new network group.

       Note that while setnetgrent() and endnetgrent() are safe for use in multi-threaded applications, the effect of each is process-wide.  Call-
       ing  setnetgrent()  resets the enumeration position for all threads. If multiple threads interleave calls to getnetgrent_r() each will enu-
       merate a disjoint subset of the netgroup. Thus the effective use of these functions in multi-threaded applications may require coordination
       by the caller.

ERRORS

       The  function  getnetgrent_r() will return  0 and set errno to ERANGE if the length of the buffer supplied by caller is not large enough to
       store the result.  See Intro(2) for the proper usage and interpretation of errno in multi-threaded applications.

       The functions setnetgrent() and endnetgrent() return 0 upon success.

FILES

       /etc/nsswitch.conf

ATTRIBUTES

       See attributes(5) for descriptions of the following attributes:

       +-----------------------------+-----------------------------+
       |      ATTRIBUTE TYPE	     |	    ATTRIBUTE VALUE	   |
       +-----------------------------+-----------------------------+
       |MT-Level		     |See DESCRIPTION section.	   |
       +-----------------------------+-----------------------------+

SEE ALSO

       Intro(2), Intro(3), netgroup(4), nsswitch.conf(4), attributes(5)

WARNINGS

       The function getnetgrent_r() is included in this release on an uncommitted basis only, and is subject to change or removal in future  minor
       releases.

NOTES

       Only the Network Information Services, NIS and NIS+, are supported as sources for the netgroup database.

       When  compiling	multi-threaded applications, see  Intro(3), Notes On Multithread Applications, for information about the use of the _REEN-
       TRANT flag.

SunOS 5.10							    5 Apr 2004							   getnetgrent(3C)