解析iw wlan0扫描输出

时间:2013-07-23 12:13:50

标签: bash parsing sed awk

我编写了wlan manager脚本来处理open / ad-hoc / wep / wpa2网络。现在我试图解析iw wlan0扫描输出,以便为我的脚本获得良好的扫描功能。我的目标是得到这样的输出:

SSID        channel     signal      encryption
wlan-ap     6           70%         wpa2-psk
test        1           55%         wep

我已经获得的是这样输出:

$ iw wlan0 scan | grep 'SSID\|freq\|signal\|capability' | tac
SSID: Koti783
signal: -82.00 dBm
capability: ESS Privacy ShortPreamble SpectrumMgmt ShortSlotTime (0x0531)
freq: 2437

我一直在尝试研究bash / sed / awk,但还没有找到一种方法来实现我的尝试。那么实现这一目标的好方法是什么?

7 个答案:

答案 0 :(得分:9)

以下是基于Sudo_O answer的最终解决方案:

$1 == "BSS" {
    MAC = $2
    wifi[MAC]["enc"] = "Open"
}
$1 == "SSID:" {
    wifi[MAC]["SSID"] = $2
}
$1 == "freq:" {
    wifi[MAC]["freq"] = $NF
}
$1 == "signal:" {
    wifi[MAC]["sig"] = $2 " " $3
}
$1 == "WPA:" {
    wifi[MAC]["enc"] = "WPA"
}
$1 == "WEP:" {
    wifi[MAC]["enc"] = "WEP"
}
END {
    printf "%s\t\t%s\t%s\t\t%s\n","SSID","Frequency","Signal","Encryption"

    for (w in wifi) {
        printf "%s\t\t%s\t\t%s\t%s\n",wifi[w]["SSID"],wifi[w]["freq"],wifi[w]["sig"],wifi[w]["enc"]
    }
}'

输出:

$ sudo iw wlan0 scan | awk -f scan.awk
SSID        Frequency   Signal      Encryption
netti       2437        -31.00 dBm  Open
Koti783     2437        -84.00 dBm  WPA
WLAN-AP     2462        -85.00 dBm  WPA

答案 1 :(得分:5)

尝试解析用于人类阅读的程序的复杂输出(而不是解析机器)通常是不好的做法。

e.g。 iw的输出可能会根据系统的语言设置和/或iw的版本而改变,只留下一个仅适用于您的开发计算机的“经理”。

相反,您可能会使用iw用来获取其信息的相同界面:库后端libnl

您可能还想查看使用libiw库的wireless-toolsiwconfigiwlist,...)。

答案 2 :(得分:5)

这是一个GNU awk脚本,可以帮助您获取每个唯一BSS的SSID和通道:

/^BSS / {
    MAC = $2
}
/SSID/ {
    wifi[MAC]["SSID"] = $2
}
/primary channel/ {
    wifi[MAC]["channel"] = $NF
}

# Insert new block here

END {
    printf "%s\t\t%s\n","SSID","channel"

    for (w in wifi) {
        printf "%s\t\t%s\n",wifi[w]["SSID"],wifi[w]["channel"]
    }
}

考虑到您正在进行的所有学习,您应该很容易添加新的信号和加密块。

将脚本保存到wifi.awk等文件并运行如下:

$ sudo iw wlan0 scan | awk -f wifi.awk

输出将采用格式化的请求:

SSID        channel
wlan-ap     6
test        1

答案 3 :(得分:4)

这是一个简单的Bash函数,它只使用Bash内部结构并只生成一个子shell:

#!/bin/bash 
function iwScan() {
   # disable globbing to avoid surprises
   set -o noglob
   # make temporary variables local to our function
   local AP S
   # read stdin of the function into AP variable
   while read -r AP; do
     ## print lines only containing needed fields
     [[ "${AP//'SSID: '*}" == '' ]] && printf '%b' "${AP/'SSID: '}\n"
     [[ "${AP//'signal: '*}" == '' ]] && ( S=( ${AP/'signal: '} ); printf '%b' "${S[0]},";)
   done
   set +o noglob
}

iwScan <<< "$(iw wlan0 scan)"

输出:

-66.00,FRITZ!Box 7312
-56.00,ALICE-WLAN01
-78.00,o2-WLAN93
-78.00,EasyBox-7A2302
-62.00,dlink
-74.00,EasyBox-59DF56
-76.00,BELAYS_Network
-82.00,o2-WLAN20
-82.00,BPPvM

可以通过在while循环中添加必要的过滤器来轻松修改该函数以提供其他字段,例如:

[[ "${AP//'last seen: '*}" == '' ]] && ( S=( ${AP/'last seen: '} ); printf '%b' "${S[0]},";)

输出:

-64.00,1000,FRITZ!Box 7312
-54.00,492,ALICE-WLAN01
-76.00,2588,o2-WLAN93
-78.00,652,LN8-Gast
-72.00,2916,WHITE-BOX
-66.00,288,ALICE-WLAN
-78.00,800,EasyBox-59DF56
-80.00,720,EasyBox-7A2302
-84.00,596,ALICE-WLAN08

答案 4 :(得分:2)

我正在使用openwrt的这种解决方案:

wlan_scan.sh

#!/bin/sh
sudo iw dev wlan0 scan | awk -f wlan_scan.awk | sort

wlan_scan.awk

/^BSS/ {
    mac = gensub ( /^BSS[[:space:]]*([0-9a-fA-F:]+).*?$/, "\\1", "g", $0 );
}
/^[[:space:]]*signal:/ {
    signal = gensub ( /^[[:space:]]*signal:[[:space:]]*(\-?[0-9.]+).*?$/, "\\1", "g", $0 );
}
/^[[:space:]]*SSID:/ {
    ssid = gensub ( /^[[:space:]]*SSID:[[:space:]]*([^\n]*).*?$/, "\\1", "g", $0 );
    printf ( "%s %s %s\n", signal, mac, ssid );
}

结果

-62.00 c8:64:c7:54:d9:05 a
-72.00 70:72:3c:1c:af:17 b
-81.00 78:f5:fd:be:33:cb c

答案 5 :(得分:0)

上面的awk脚本中有一个错误。

如果SSID名称中有空格,则以下代码将不起作用。收到的结果将仅是SSID名称的第一个令牌。

$1 == "SSID:" {
    wifi[MAC]["SSID"] = $2
}

打印$ 0,$ 1,$ 2时

$0:     SSID: DIRECT-82-HP OfficeJet 8700
$1: SSID:
$2: DIRECT-82-HP

一种可能的解决方案是采用$ 0的子字符串,其中包含前导空格,令牌“ SSID:”和提供的多令牌网络名称。

还有其他建议吗?

答案 6 :(得分:0)

我从Ari Malinen中提取了awk代码,并对其进行了一些重做,因为iw输出不稳定且发生变化,还存在其他问题,例如SSID中的空格。我将其放在github上,以防将来将来更改。

#!/usr/bin/env awk -f

$1 ~ /^BSS/ {
    if($2 !~ /Load:/) { #< Escape "BBS Load:" line
        gsub("(\\(.*|:)", "", $2)
        MAC = toupper($2)
        wifi[MAC]["enc"] = "OPEN"
        wifi[MAC]["WPS"] = "no"
        wifi[MAC]["wpa1"] = ""
        wifi[MAC]["wpa2"] = ""
        wifi[MAC]["wep"] = ""
    }
}
$1 == "SSID:" {
    # Workaround spaces in SSID
    FS=":" #< Changing field separator on ":", it should be
           #  forbidded sign for SSID name
    $0=$0
    sub(" ", "", $2) #< remove first whitespace
    wifi[MAC]["SSID"] = $2
    FS=" "
    $0=$0
}
$1 == "capability:" {
    for(i=2; i<=NF; i++) {
        if($i ~ /0x[0-9]{4}/) {
            gsub("(\\(|\\))", "", $i)
            if (and(strtonum($i), 0x10)) 
                wifi[MAC]["wep"] = "WEP"
        }
    }
}
$1 == "WPA:" {
    wifi[MAC]["wpa1"] = "WPA1"
}
$1 == "RSN:" {
    wifi[MAC]["wpa2"] = "WPA2"
}
$1 == "WPS:" {
    wifi[MAC]["WPS"] = "yes"
}
$1 == "DS" {
    wifi[MAC]["Ch"] = $5
}
$1 == "signal:" {
    match($2, /-([0-9]{2})\.00/, m)
    wifi[MAC]["Sig"] = m[1]
}
$1 == "TSF:" {
    gsub("(\\(|d|,)", "", $4)
    match($5, /([0-9]{2}):([0-9]{2}):/, m)
    day = $4
    hour = m[1]
    min = m[2]
    wifi[MAC]["TSF"] = day"d"hour"h"min"m"
}
END {
    for (w in wifi) {
        if (wifi[w]["wep"]) {
            if (wifi[w]["wpa1"] || wifi[w]["wpa2"])
                wifi[w]["enc"] = wifi[w]["wpa1"]wifi[w]["wpa2"]
            else
                wifi[w]["enc"] = "WEP"
        }
        printf "%s:%s:%s:%s:%s:%s:%s\n", w, wifi[w]["SSID"], wifi[w]["enc"], \
               wifi[w]["WPS"], wifi[w]["Ch"], wifi[w]["Sig"], wifi[w]["TSF"]
    }
}

输出:

A5FEF2C499BB:test-ssid2:OPEN:no:9:43:0d00h00m
039EFACA9A8B:test-ssid2:WPA1:no:9:33:0d00h00m
038BF3C1988B:test-ssid2:WPA2:no:9:35:0d00h00m
028EF3C2997B:test-ssid2:WPA1:no:9:35:0d00h03m

如果您想知道if($2 !~ /Load:/)是做什么的,那么在某些路由器上可能会出现“ BSS Load:”字符串。