1/* Copyright (C) 1991-2025 Free Software Foundation, Inc.
  2   This file is part of the GNU C Library.
  3
  4   The GNU C Library is free software; you can redistribute it and/or
  5   modify it under the terms of the GNU Lesser General Public
  6   License as published by the Free Software Foundation; either
  7   version 2.1 of the License, or (at your option) any later version.
  8
  9   The GNU C Library is distributed in the hope that it will be useful,
 10   but WITHOUT ANY WARRANTY; without even the implied warranty of
 11   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 12   Lesser General Public License for more details.
 13
 14   You should have received a copy of the GNU Lesser General Public
 15   License along with the GNU C Library; if not, see
 16   <https://www.gnu.org/licenses/>.  */
 17
 18/*
 19 *	POSIX Standard: 9.2.1 Group Database Access	<grp.h>
 20 */
 21
 22#ifndef	_GRP_H
 23#define	_GRP_H	1
 24
 25#include <features.h>
 26
 27__BEGIN_DECLS
 28
 29#include <bits/types.h>
 30
 31#define __need_size_t
 32#include <stddef.h>
 33
 34
 35/* For the Single Unix specification we must define this type here.  */
 36#if (defined __USE_XOPEN || defined __USE_XOPEN2K) && !defined __gid_t_defined
 37typedef __gid_t gid_t;
 38# define __gid_t_defined
 39#endif
 40
 41/* The group structure.	 */
 42struct group
 43  {
 44    char *gr_name;		/* Group name.	*/
 45    char *gr_passwd;		/* Password.	*/
 46    __gid_t gr_gid;		/* Group ID.	*/
 47    char **gr_mem;		/* Member list.	*/
 48  };
 49
 50
 51#ifdef __USE_MISC
 52# include <bits/types/FILE.h>
 53#endif
 54
 55
 56#if defined __USE_MISC || defined __USE_XOPEN_EXTENDED
 57/* Rewind the group-file stream.
 58
 59   This function is a possible cancellation point and therefore not
 60   marked with __THROW.  */
 61extern void setgrent (void);
 62
 63/* Close the group-file stream.
 64
 65   This function is a possible cancellation point and therefore not
 66   marked with __THROW.  */
 67extern void endgrent (void);
 68
 69/* Read an entry from the group-file stream, opening it if necessary.
 70
 71   This function is a possible cancellation point and therefore not
 72   marked with __THROW.  */
 73extern struct group *getgrent (void);
 74#endif
 75
 76#ifdef	__USE_MISC
 77/* Read a group entry from STREAM.
 78
 79   This function is not part of POSIX and therefore no official
 80   cancellation point.  But due to similarity with an POSIX interface
 81   or due to the implementation it is a cancellation point and
 82   therefore not marked with __THROW.  */
 83extern struct group *fgetgrent (FILE *__stream);
 84#endif
 85
 86#ifdef __USE_GNU
 87/* Write the given entry onto the given stream.
 88
 89   This function is not part of POSIX and therefore no official
 90   cancellation point.  But due to similarity with an POSIX interface
 91   or due to the implementation it is a cancellation point and
 92   therefore not marked with __THROW.  */
 93extern int putgrent (const struct group *__restrict __p,
 94		     FILE *__restrict __f);
 95#endif
 96
 97/* Search for an entry with a matching group ID.
 98
 99   This function is a possible cancellation point and therefore not
100   marked with __THROW.  */
101extern struct group *getgrgid (__gid_t __gid);
102
103/* Search for an entry with a matching group name.
104
105   This function is a possible cancellation point and therefore not
106   marked with __THROW.  */
107extern struct group *getgrnam (const char *__name);
108
109#ifdef __USE_POSIX
110
111# ifdef __USE_MISC
112/* Reasonable value for the buffer sized used in the reentrant
113   functions below.  But better use `sysconf'.  */
114#  define NSS_BUFLEN_GROUP	1024
115# endif
116
117/* Reentrant versions of some of the functions above.
118
119   PLEASE NOTE: the `getgrent_r' function is not (yet) standardized.
120   The interface may change in later versions of this library.  But
121   the interface is designed following the principals used for the
122   other reentrant functions so the chances are good this is what the
123   POSIX people would choose.
124
125   This function is not part of POSIX and therefore no official
126   cancellation point.  But due to similarity with an POSIX interface
127   or due to the implementation it is a cancellation point and
128   therefore not marked with __THROW.  */
129
130# ifdef __USE_GNU
131extern int getgrent_r (struct group *__restrict __resultbuf,
132		       char *__restrict __buffer, size_t __buflen,
133		       struct group **__restrict __result)
134	__attr_access ((__write_only__, 2, 3));
135# endif
136
137/* Search for an entry with a matching group ID.
138
139   This function is a possible cancellation point and therefore not
140   marked with __THROW.  */
141extern int getgrgid_r (__gid_t __gid, struct group *__restrict __resultbuf,
142		       char *__restrict __buffer, size_t __buflen,
143		       struct group **__restrict __result)
144	__attr_access ((__write_only__, 3, 4));
145
146/* Search for an entry with a matching group name.
147
148   This function is a possible cancellation point and therefore not
149   marked with __THROW.  */
150extern int getgrnam_r (const char *__restrict __name,
151		       struct group *__restrict __resultbuf,
152		       char *__restrict __buffer, size_t __buflen,
153		       struct group **__restrict __result)
154	__attr_access ((__write_only__, 3, 4));
155
156# ifdef	__USE_MISC
157/* Read a group entry from STREAM.  This function is not standardized
158   an probably never will.
159
160   This function is not part of POSIX and therefore no official
161   cancellation point.  But due to similarity with an POSIX interface
162   or due to the implementation it is a cancellation point and
163   therefore not marked with __THROW.  */
164extern int fgetgrent_r (FILE *__restrict __stream,
165			struct group *__restrict __resultbuf,
166			char *__restrict __buffer, size_t __buflen,
167			struct group **__restrict __result)
168	__attr_access ((__write_only__, 3, 4));
169# endif
170
171#endif	/* POSIX or reentrant */
172
173
174#ifdef	__USE_MISC
175
176# define __need_size_t
177# include <stddef.h>
178
179/* Set the group set for the current user to GROUPS (N of them).  */
180extern int setgroups (size_t __n, const __gid_t *__groups) __THROW;
181
182/* Store at most *NGROUPS members of the group set for USER into
183   *GROUPS.  Also include GROUP.  The actual number of groups found is
184   returned in *NGROUPS.  Return -1 if the if *NGROUPS is too small.
185
186   This function is not part of POSIX and therefore no official
187   cancellation point.  But due to similarity with an POSIX interface
188   or due to the implementation it is a cancellation point and
189   therefore not marked with __THROW.  */
190extern int getgrouplist (const char *__user, __gid_t __group,
191			 __gid_t *__groups, int *__ngroups);
192
193/* Initialize the group set for the current user
194   by reading the group database and using all groups
195   of which USER is a member.  Also include GROUP.
196
197   This function is not part of POSIX and therefore no official
198   cancellation point.  But due to similarity with an POSIX interface
199   or due to the implementation it is a cancellation point and
200   therefore not marked with __THROW.  */
201extern int initgroups (const char *__user, __gid_t __group);
202
203#endif /* Use misc.  */
204
205__END_DECLS
206
207#endif /* grp.h  */