setgroups(2)
NAME
setgroups − set group access list
SYNTAX
#include <sys/param.h>
setgroups(ngroups, gidset)
int ngroups, *gidset;
DESCRIPTION
The setgroups system call sets the group access list of the current user process according to 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 superuser may set new groups.
A 0 value is returned on success, −1 on an error, with the error code stored in errno.
DIAGNOSTICS
The setgroups call will fail if:
[EPERM] The caller is not the superuser.
[EFAULT] The address specified for gidset is outside the process address space.