getgrent, setgrent, endgrent: získat záznam skupinového souboru

Originální popis anglicky: getgrent, setgrent, endgrent - get group file entry

Návod, kniha: Linux Programmer's Manual

STRUČNĚ

#include <sys/types.h>
#include <grp.h>
 
struct group *getgrent(void);
 
void setgrent(void);
 
void endgrent(void);

The getgrent() function returns a pointer to a structure containing the group information from /etc/group. The first time it is called it returns the first entry; thereafter, it returns successive entries.

The setgrent() function rewinds the file pointer to the beginning of the /etc/group file.

The endgrent() function closes the /etc/group file.

The group structure is defined in <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 */
};

NÁVRATOVÁ HODNOTA

The getgrent() function returns the group information structure, or NULL if there are no more entries or an error occurs.

Upon error, errno may be set. If you want to check its value, set it to zero before the call.

CHYBY / ERRORY

EINTR: A signal was caught.

EIO: I/O error.

EMFILE: The calling process already has too many open files.

ENFILE: Too many open files in the system.

ENOMEM: Insufficient memory to allocate group information structure.

FILES

/etc/group: group database file

ODPOVÍDAJÍCÍ

SVID 3, BSD 4.3, POSIX 1003.1-2003.

SOUVISEJÍCÍ

fgetgrent(3), getgrent_r(3), getgrgid(3), getgrnam(3)

1993-04-04