// EXIT:0
// OUTPUT:read 64 bytes
// OUTPUT:first line: // EXIT:0
unit readfile;
import std.io;

// Reads its own source and reports the first line. A program that can open a
// file is a program that can be a compiler.

fn main() -> i32 {
    var path: [64]u8 = [0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
                        0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
                        0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
                        0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0];
    let n: usize = io.to_cstr(path[..], "fec/tests/exec/readfile.fe");
    let handle: i32 = io.open_read(path[0..n]) catch |e| {
        @print("cannot open\n");
        return 1;
    };
    var buf: [64]u8 = [0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
                       0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
                       0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
                       0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0];
    let got: usize = io.read(handle, buf[..]) catch |e| {
        io.close(handle);
        return 2;
    };
    io.close(handle);
    @print("read {} bytes\n", n);
    var stop: usize = 0;
    while stop < got {
        if buf[stop] == 10 { break; }
        stop = stop + 1;
    }
    @print("first line: {}\n", buf[0..stop]);
    return 0;
}