SETGROUPS(2)
NAME
setgroups − set group access list
USAGE
#include <sys/param.h>
setgroups(ngroups, gidset) int ngroups, *gidset;
DESCRIPTION
Setgroups sets the group access list of the current user process to the one specified by the array gidset. The parameter ngroups indicates the number of entries in the array and must be no more than NGROUPS, as defined in <sys/param.h>.
Only the super-user can set new groups.
RETURN VALUE
A successful call returns zero. A failed call returns -1 and sets errno as indicated below.
ERRORS
The setgroups call fails if:
[EPERM] The caller is not the super-user.
[EFAULT] The address specified for gidset is outside the process’s legal address space.