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1 /* Copyright (C) 1991-2015 Free Software Foundation, Inc.
2 This file is part of the GNU C Library.
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.
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.
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 <http://www.gnu.org/licenses/>. */
19 * POSIX Standard: 9.2.1 Group Database Access <grp.h>
22 #ifndef _GRP_H
23 #define _GRP_H 1
25 #include <features.h>
27 __BEGIN_DECLS
29 #include <bits/types.h>
31 #define __need_size_t
32 #include <stddef.h>
35 /* For the Single Unix specification we must define this type here. */
36 #if (defined __USE_XOPEN || defined __USE_XOPEN2K) && !defined __gid_t_defined
37 typedef __gid_t gid_t;
38 # define __gid_t_defined
39 #endif
41 /* The group structure. */
42 struct group
44 char *gr_name; /* Group name. */
45 char *gr_passwd; /* Password. */
46 __gid_t gr_gid; /* Group ID. */
47 char **gr_mem; /* Member list. */
51 #ifdef __USE_MISC
52 # define __need_FILE
53 # include <stdio.h>
54 #endif
57 #if defined __USE_MISC || defined __USE_XOPEN_EXTENDED
58 /* Rewind the group-file stream.
60 This function is a possible cancellation point and therefore not
61 marked with __THROW. */
62 extern void setgrent (void);
63 #endif
65 #if defined __USE_XOPEN_EXTENDED || defined __USE_XOPEN2K8
66 /* Close the group-file stream.
68 This function is a possible cancellation point and therefore not
69 marked with __THROW. */
70 extern void endgrent (void);
72 /* Read an entry from the group-file stream, opening it if necessary.
74 This function is a possible cancellation point and therefore not
75 marked with __THROW. */
76 extern struct group *getgrent (void);
77 #endif
79 #ifdef __USE_MISC
80 /* Read a group entry from STREAM.
82 This function is not part of POSIX and therefore no official
83 cancellation point. But due to similarity with an POSIX interface
84 or due to the implementation it is a cancellation point and
85 therefore not marked with __THROW. */
86 extern struct group *fgetgrent (FILE *__stream);
87 #endif
89 #ifdef __USE_GNU
90 /* Write the given entry onto the given stream.
92 This function is not part of POSIX and therefore no official
93 cancellation point. But due to similarity with an POSIX interface
94 or due to the implementation it is a cancellation point and
95 therefore not marked with __THROW. */
96 extern int putgrent (const struct group *__restrict __p,
97 FILE *__restrict __f);
98 #endif
100 /* Search for an entry with a matching group ID.
102 This function is a possible cancellation point and therefore not
103 marked with __THROW. */
104 extern struct group *getgrgid (__gid_t __gid);
106 /* Search for an entry with a matching group name.
108 This function is a possible cancellation point and therefore not
109 marked with __THROW. */
110 extern struct group *getgrnam (const char *__name);
112 #ifdef __USE_POSIX
114 # ifdef __USE_MISC
115 /* Reasonable value for the buffer sized used in the reentrant
116 functions below. But better use `sysconf'. */
117 # define NSS_BUFLEN_GROUP 1024
118 # endif
120 /* Reentrant versions of some of the functions above.
122 PLEASE NOTE: the `getgrent_r' function is not (yet) standardized.
123 The interface may change in later versions of this library. But
124 the interface is designed following the principals used for the
125 other reentrant functions so the chances are good this is what the
126 POSIX people would choose.
128 This function is not part of POSIX and therefore no official
129 cancellation point. But due to similarity with an POSIX interface
130 or due to the implementation it is a cancellation point and
131 therefore not marked with __THROW. */
133 # ifdef __USE_GNU
134 extern int getgrent_r (struct group *__restrict __resultbuf,
135 char *__restrict __buffer, size_t __buflen,
136 struct group **__restrict __result);
137 # endif
139 /* Search for an entry with a matching group ID.
141 This function is a possible cancellation point and therefore not
142 marked with __THROW. */
143 extern int getgrgid_r (__gid_t __gid, struct group *__restrict __resultbuf,
144 char *__restrict __buffer, size_t __buflen,
145 struct group **__restrict __result);
147 /* Search for an entry with a matching group name.
149 This function is a possible cancellation point and therefore not
150 marked with __THROW. */
151 extern int getgrnam_r (const char *__restrict __name,
152 struct group *__restrict __resultbuf,
153 char *__restrict __buffer, size_t __buflen,
154 struct group **__restrict __result);
156 # ifdef __USE_MISC
157 /* Read a group entry from STREAM. This function is not standardized
158 an probably never will.
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. */
164 extern int fgetgrent_r (FILE *__restrict __stream,
165 struct group *__restrict __resultbuf,
166 char *__restrict __buffer, size_t __buflen,
167 struct group **__restrict __result);
168 # endif
170 #endif /* POSIX or reentrant */
173 #ifdef __USE_MISC
175 # define __need_size_t
176 # include <stddef.h>
178 /* Set the group set for the current user to GROUPS (N of them). */
179 extern int setgroups (size_t __n, const __gid_t *__groups) __THROW;
181 /* Store at most *NGROUPS members of the group set for USER into
182 *GROUPS. Also include GROUP. The actual number of groups found is
183 returned in *NGROUPS. Return -1 if the if *NGROUPS is too small.
185 This function is not part of POSIX and therefore no official
186 cancellation point. But due to similarity with an POSIX interface
187 or due to the implementation it is a cancellation point and
188 therefore not marked with __THROW. */
189 extern int getgrouplist (const char *__user, __gid_t __group,
190 __gid_t *__groups, int *__ngroups);
192 /* Initialize the group set for the current user
193 by reading the group database and using all groups
194 of which USER is a member. Also include GROUP.
196 This function is not part of POSIX and therefore no official
197 cancellation point. But due to similarity with an POSIX interface
198 or due to the implementation it is a cancellation point and
199 therefore not marked with __THROW. */
200 extern int initgroups (const char *__user, __gid_t __group);
202 #endif /* Use misc. */
204 __END_DECLS
206 #endif /* grp.h */