grp.h - group structure
The <grp.h> header shall declare the structure group which shall
include the following members:
char *gr_name The name of the group.
gid_t gr_gid Numerical group ID.
char **gr_mem Pointer to a null-terminated array of character
pointers to member names.
The gid_t type shall be defined as described in <sys/types.h> .
The following shall be declared as functions and may also be defined as
macros. Function prototypes shall be provided.
struct group *getgrgid(gid_t);
struct group *getgrnam(const char *);
int getgrgid_r(gid_t, struct group *, char *,
size_t, struct group **);
int getgrnam_r(const char *, struct group *, char *,
size_t , struct group **);
struct group *getgrent(void);
The following sections are informative.
<sys/types.h> , the System Interfaces volume of IEEE Std 1003.1-2001,
endgrent(), getgrgid(), getgrnam()
Portions of this text are reprinted and reproduced in electronic form
from IEEE Std 1003.1, 2003 Edition, Standard for Information Technology
-- Portable Operating System Interface (POSIX), The Open Group Base
Specifications Issue 6, Copyright (C) 2001-2003 by the Institute of
Electrical and Electronics Engineers, Inc and The Open Group. In the
event of any discrepancy between this version and the original IEEE and
The Open Group Standard, the original IEEE and The Open Group Standard
is the referee document. The original Standard can be obtained online
at http://www.opengroup.org/unix/online.html .