GETGROUPLIST(3) Library Functions Manual GETGROUPLIST(3)
getgrouplist, getgroupmembership, -- calculate group access list
Standard C Library (libc, -lc)
getgrouplist(const char *name, gid_t basegid, gid_t *groups, int
getgroupmembership(const char *name, gid_t basegid, gid_t *groups, int
maxgrp, int *ngroups);
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
The resulting group list is returned in the integer array pointed to by
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.
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.
/etc/group group membership list
setgroups(2), initgroups(3), group(5)
The getgrouplist() function first appeared in 4.4BSD. The
getgroupmembership() function first appeared in NetBSD 3.0 to address an
API deficiency in getgrouplist().
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().
NetBSD 6.1.5 January 6, 2005 NetBSD 6.1.5