fs
Package fs.
POSIX file I/O on integer fds. open is read-only; create is write/trunc. read/write/close use the fd. mkdir creates one directory. Every call returns result[_, str]. These calls block the worker — use them for config and small files, not the accept loop.
import "fs";
let cr = fs.create("/tmp/note");
guard let fd = cr else { exit(1); }
fs.write(fd, b"hi");
fs.close(fd);
let or = fs.open("/tmp/note");
guard let in_fd = or else { exit(1); }
let rr = fs.read(in_fd, 16);
guard let data = rr else { exit(1); }
fs.close(in_fd);