nss/grp.h

   1 /* Copyright (C) 1991-2024 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
  37 typedef __gid_t gid_t;
  38 # define __gid_t_defined
  39 #endif
  40
  41 /* The group structure.  */
  42 struct 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.  */
  61 extern 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.  */
  67 extern 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.  */
  73 extern 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.  */
  83 extern 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.  */
  93 extern 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.  */
 101 extern 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.  */
 107 extern 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
 131 extern 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.  */
 141 extern 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.  */
 150 extern 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.  */
 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         __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).  */
 180 extern 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.  */
 190 extern 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.  */
 201 extern int initgroups (const char *__user, __gid_t __group);
 202
 203 #endif /* Use misc.  */
 204
 205 __END_DECLS
 206
 207 #endif /* grp.h  */