NAME
getgrouplist,
getgroupmembership, —
calculate group access list
LIBRARY
Standard C Library (libc, -lc)
SYNOPSIS
#include <unistd.h>
int
getgrouplist(
const
char *name,
gid_t
basegid,
gid_t
*groups,
int
*ngroups);
int
getgroupmembership(
const
char *name,
gid_t
basegid,
gid_t
*groups,
int maxgrp,
int *ngroups);
DESCRIPTION
The
getgrouplist() and
getgroupmembership()
functions read through the group database and calculate the group access list
for the user specified in
name. The
basegid is automatically included in the groups list.
Typically this value is given as the group number from the password database.
The resulting group list is returned in the integer array pointed to by
groups.
For
getgrouplist(), the caller specifies the size of the
groups array in the integer pointed to by
ngroups.
For
getgroupmembership(), the caller specifies the size of the
groups array in
maxgrp.
The actual number of groups found is returned in
ngroups.
Duplicate group ids will be suppressed from the result.
RETURN VALUES
The
getgrouplist() and
getgroupmembership()
functions return 0 if successful, and return -1 if the size of the group list
is too small to hold all the user's groups. In the latter case, the
groups array will be filled with as many groups as will
fit and
ngroups will contain the total number of groups
found.
FILES
- /etc/group
- group membership list
SEE ALSO
setgroups(2),
initgroups(3),
group(5)
HISTORY
The
getgrouplist() function first appeared in
4.4BSD. The
getgroupmembership()
function first appeared in
NetBSD 3.0 to address an
API deficiency in
getgrouplist().
BUGS
The
getgrouplist() function uses the routines based on
getgrent(3). If the invoking
program uses any of these routines, the group structure will be overwritten in
the call to
getgrouplist().