enumerate groups, Take One (chatGPT edition)

enum_grp1.rs

extern crate libc;
use libc::{group, setgrent, getgrent, endgrent, gid_t};
use std::ffi::CStr;
use std::ptr;

struct Group {
    name: String,
    passwd: String,
    gid: gid_t,
    members: Vec<String>,
}

fn load_group_db() -> Vec<Group> {
    let mut groups = Vec::new();

    unsafe { setgrent() };

    loop {
        unsafe {
            let group_ptr = getgrent();
            if group_ptr.is_null() {
                break;
            }

            let group = &*group_ptr;  // Dereference once and use it safely within the block

            let name = CStr::from_ptr(group.gr_name).to_string_lossy().to_string();
            let passwd = CStr::from_ptr(group.gr_passwd).to_string_lossy().to_string();
            let gid = group.gr_gid;
            let mut members = Vec::new();

            let mut member_ptr = group.gr_mem;
            while !(*member_ptr).is_null() {
                let member_c_str = CStr::from_ptr(*member_ptr);
                members.push(member_c_str.to_string_lossy().to_string());
                member_ptr = member_ptr.add(1);  // Correctly advance to the next pointer
            }

            groups.push(Group {
                name,
                passwd,
                gid,
                members,
            });
        }
    }

    unsafe { endgrent() };

    groups
}

fn main() {
    let groups = load_group_db();
    for group in groups {
        println!("Group: {} (GID: {})", group.name, group.gid);
        println!("Members: {:?}", group.members);
    }
}