NAME
getgrouplist,
getgroupmembership —
calculate group access list
LIBRARY
library “libc”
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
Thegetgrouplist()
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
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().