1

大家好，我正在尝试为我的服务器编写一个 wol 脚本。树莓派每次启动时都会执行。

我猜它是一个语法错误，但我现在没有解决方案，所以我问你。我在第 5 行遇到错误，但不知道如何纠正它。

#!/bin/bash

nas=[ping -c 1 192.192.168.222.5 &> /dev/null ]

until [ $nas = "1" ];do
python wol.py
sleep 2
nas=[ping -c 1 192.192.168.222.5 &> /dev/null ]
done

wol.py 是来自 marc balmar 的脚本，它发送 wol 包

#!/usr/bin/env python
#coding: utf8

# Wake-On-LAN
#
# Copyright (C) 2002 by Micro Systems Marc Balmer
# Written by Marc Balmer, marc@msys.ch, http://www.msys.ch/
# Modified by saarnu for nerdoskop.wordpress.com
# This code is free software under the GPL

import struct, socket, time, os

def WakeOnLan(ethernet_address):

  # Construct a six-byte hardware address

  addr_byte = ethernet_address.split(':')
  hw_addr = struct.pack('BBBBBB', int(addr_byte[0], 16),
    int(addr_byte[1], 16),
    int(addr_byte[2], 16),
    int(addr_byte[3], 16),
    int(addr_byte[4], 16),
    int(addr_byte[5], 16))

  # Build the Wake-On-LAN "Magic Packet"...

  msg = '\xff' * 6 + hw_addr * 16

  # ...and send it to the broadcast address using UDP
  time.sleep(5)
  s = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
  s.setsockopt(socket.SOL_SOCKET, socket.SO_BROADCAST, 1)
  s.sendto(msg, ('<broadcast>', 9))
  s.close()

WakeOnLan('C8:60:00:6D:CF:54') # MAC-Adresse der DiskStation

我在 powershell 中编写了一个类似的代码，我实际上是在尝试复制它或将它翻译成 bash，这要容易得多。

$NAS = test-connection -count 1 -quiet 192.168.222.5
if ($NAS -like "False"){
do
{
$Mac = "C8:60:00:6D:CF:54"
$MacByteArray = $Mac -split "[:-]" | ForEach-Object { [Byte] "0x$_"}
[Byte[]] $MagicPacket = (,0xFF * 6) + ($MacByteArray  * 16)
$UdpClient = New-Object System.Net.Sockets.UdpClient
$UdpClient.Connect(([System.Net.IPAddress]::Broadcast),7)
$UdpClient.Send($MagicPacket,$MagicPacket.Length)
$UdpClient.Close()
Start-Sleep -s 5
$NAS = test-connection -count 1 -quiet 192.168.222.5
}
until
(
$NAS -like "True"
)
}
4

2 回答 2

1

首先，使用http://www.shellcheck.net修复脚本中的语法问题。

您的命令替换语法错误，使用该修复程序并ping直接在until-loop

until ping -c 1 192.192.168.222.5 &> /dev/null
do
    python wol.py
    sleep 2
done

应该可以解决您的问题。man页面ping说_

如果 ping 根本没有收到任何回复数据包，它将以代码 1 退出。如果同时指定了数据包计数和截止时间，并且在截止时间到达时收到的数据包少于计数，它也会以代码 1 退出。在其他错误时，它以代码 2 退出。否则，它以代码 0 退出。这使得可以使用退出代码来查看主机是否处于活动状态。

于 2017-01-20T17:35:47.143 回答
0

嘿，您的 bash 脚本中有几个错误，而不仅仅是一个。

#!/bin/bash

# This is a silent ping. The output is redirected to /dev/null. The only visible
# change in user-land will be the exit code, available as $?.
# The exit code "0" means success, the exit code "1" means some error.

ping -c 1 192.192.168.222.5 &> /dev/null

# You need double round parenthesis here to evaluate a comparison.
# Also a comparison, as almost everywhere in programming, is "==" instead of "=".
until (( $? == "0" ));
    do
    python wol.py
    sleep 2
    # There is the silent ping again. Updating $?.
    ping -c 1 192.192.168.222.5 &> /dev/null
done

有关退出代码，请参阅： 基于进程退出代码的退出 Shell 脚本

对于不同的括号/括号，请参阅非常好的 bash 手册man bash，如何使用双括号或单括号、括号、花括号或https://stackoverflow.com/a/9666169/7236811。

于 2017-01-20T17:51:28.793 回答