GETGRENT(3) Linux Programmer's Manual GETGRENT(3)
NAME
getgrent, setgrent, endgrent - get group file(1,n) entry
SYNOPSIS
#include <sys/types.h>
#include <grp.h>
struct group *getgrent(void);
void setgrent(void);
void endgrent(void);
DESCRIPTION
The getgrent() function returns a pointer to a structure containing the
group information from /etc/group. The first time(1,2,n) it is called it
returns the first entry; thereafter, it returns successive entries.
The setgrent() function rewinds the file(1,n) pointer to the beginning of
the /etc/group file.
The endgrent() function closes the /etc/group file.
The group structure is defined in(1,8) <grp.h> as follows:
struct group {
char *gr_name; /* group name */
char *gr_passwd; /* group password */
gid_t gr_gid; /* group id */
char **gr_mem; /* group members */
};
RETURN VALUE
The getgrent() function returns the group information structure, or
NULL if(3,n) there are no more entries or an error(8,n) occurs.
Upon error(8,n), errno may be set. If you want to check its value, set(7,n,1 builtins) it to
zero before the call.
ERRORS
EINTR A signal(2,7) was caught.
EIO I/O error.
EMFILE The calling process already has too many open(2,3,n) files.
ENFILE Too many open(2,3,n) files in(1,8) the system.
ENOMEM Insufficient memory to allocate group information structure.
FILES
/etc/group
group database file(1,n)
CONFORMING TO
SVID 3, BSD 4.3, POSIX 1003.1-2003.
SEE ALSO
fgetgrent(3), getgrent_r(3), getgrgid(3), getgrnam(3)
1993-04-04 GETGRENT(3)