Jinsi ya kutumia std::sys

std::sys ni safu ya kufunika OS chini ya module zenye kiwango cha juu.

std(high-level)
  -> sys dispatcher
  -> sys/linux or sys/macos
  -> syscall

Mkataba wa msingi

• Kazi nyingi zinarudisha thamani za mfumo za msingi.
• >= 0 mafanikio, < 0 kushindwa(-errno).
• Katika msimbo wa programu wa kiwango cha juu, tumia std::sys, std::net, std::time kwanza badala ya std::env inapowezekana.

1. Mfano wa kusoma faili (std::sys::fs)

import("std::sys::fs");

fun main() {
    var fd: i64 = open("/etc/hosts", 0, 0);
    if (fd < 0) {
        return;
    }

    var buf: array<u8, 256>;
    var n: i64 = read(fd, &buf[0], 256);
    close(fd);
}

2. Mfano wa soketi (std::sys::socket)

import("std::sys::socket");

fun main() {
    var fd: i64 = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP);
    if (fd < 0) {
        return;
    }

    shutdown(fd, SHUT_RDWR);
}

3. Mfano wa kumbukumbu (std::sys::memory)

import("std::sys::memory");

fun main() {
    var p: ptr<u8> = sys_alloc(4096);
    if (p == null) {
        return;
    }

    sys_free(p, 4096);
}

moduli ya dispatcher

• std::sys::socket
• std::sys::fs
• std::sys::env
• std::sys::memory
• std::sys::process
• std::sys::time
• std::sys::tty

#[target(os="linux")], #[target(os="macos")] matawi yanatumika tu ndani ya dispatcher.