1extern fn printf(format: [*:0]const u8, ...) c_int;
 2extern fn strlen(str: [*:0]const u8) usize;
 3
 4const msg = "Hello, world!\n";
 5
 6pub export fn main(argc: c_int, argv: **u8) c_int {
 7    _ = argv;
 8    _ = argc;
 9    if (printf(msg) != @as(c_int, @intCast(strlen(msg)))) return -1;
10    return 0;
11}