GETGROUPLIST(3) BSD 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 *ngroups);
getgroupmembership(const char *name, gid_t basegid, gid_t *groups, int maxgrp,
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 automati-
cally 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.
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 con-
tain 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
BSD January 6, 2005 BSD