gethostname

pub fn gethostname(name_buffer: *[HOST_NAME_MAX]u8) GetHostNameError![]u8 {
    if (builtin.link_libc) {
        switch (errno(system.gethostname(name_buffer, name_buffer.len))) {
            .SUCCESS => return mem.sliceTo(name_buffer, 0),
            .FAULT => unreachable,
            .NAMETOOLONG => unreachable, // HOST_NAME_MAX prevents this
            .PERM => return error.PermissionDenied,
            else => |err| return unexpectedErrno(err),
        }
    }
    if (native_os == .linux) {
        const uts = uname();
        const hostname = mem.sliceTo(&uts.nodename, 0);
        const result = name_buffer[0..hostname.len];
        @memcpy(result, hostname);
        return result;
    }

    @compileError("TODO implement gethostname for this OS");
}