1GETGRENT(3)                Linux Programmer's Manual               GETGRENT(3)
2
3
4

NAME

6       getgrent, setgrent, endgrent - get group file entry
7

SYNOPSIS

9       #include <sys/types.h>
10       #include <grp.h>
11
12       struct group *getgrent(void);
13
14       void setgrent(void);
15
16       void endgrent(void);
17
18   Feature Test Macro Requirements for glibc (see feature_test_macros(7)):
19
20       getgrent(), setgrent(), endgrent(): _SVID_SOURCE || _BSD_SOURCE ||
21       _XOPEN_SOURCE >= 500
22

DESCRIPTION

24       The getgrent() function returns a pointer to a structure containing the
25       broken-out  fields  of  a record in the group database (e.g., the local
26       group file /etc/group, NIS, and LDAP).  The first time it is called  it
27       returns the first entry; thereafter, it returns successive entries.
28
29       The setgrent() function rewinds to the beginning of the group database,
30       to allow repeated scans.
31
32       The endgrent() function is used to close the group database  after  all
33       processing has been performed.
34
35       The group structure is defined in <grp.h> as follows:
36
37           struct group {
38               char   *gr_name;       /* group name */
39               char   *gr_passwd;     /* group password */
40               gid_t   gr_gid;        /* group ID */
41               char  **gr_mem;        /* group members */
42           };
43

RETURN VALUE

45       The getgrent() function returns a pointer to a group structure, or NULL
46       if there are no more entries or an error occurs.
47
48       Upon error, errno may be set.  If one wants to check  errno  after  the
49       call, it should be set to zero before the call.
50
51       The  return value may point to a static area, and may be overwritten by
52       subsequent calls to getgrent(), getgrgid(3), or getgrnam(3).   (Do  not
53       pass the returned pointer to free(3).)
54

ERRORS

56       EINTR  A signal was caught.
57
58       EIO    I/O error.
59
60       EMFILE The calling process already has too many open files.
61
62       ENFILE Too many open files in the system.
63
64       ENOMEM Insufficient memory to allocate group structure.
65
66       ERANGE Insufficient buffer space supplied.
67

FILES

69       /etc/group
70              local group database file
71

CONFORMING TO

73       SVr4, 4.3BSD, POSIX.1-2001.
74

SEE ALSO

76       fgetgrent(3), getgrent_r(3), getgrgid(3), getgrnam(3), getgrouplist(3),
77       putgrent(3)
78

COLOPHON

80       This page is part of release 3.25 of the Linux  man-pages  project.   A
81       description  of  the project, and information about reporting bugs, can
82       be found at http://www.kernel.org/doc/man-pages/.
83
84
85
86                                  2009-03-30                       GETGRENT(3)
Impressum