Function nc::getgroups

pub fn getgroups(size: i32, group_list: &mut [gid_t]) -> Result<i32, Errno>

Get list of supplementary group Ids.

let mut groups = vec![];
let ret = nc::getgroups(0, &mut groups);
assert!(ret.is_ok());
let total_num = ret.unwrap();
groups.resize(total_num as usize, 0);
let ret = nc::getgroups(total_num, &mut groups);
assert!(ret.is_ok());
assert_eq!(ret, Ok(total_num));