iwlist扫描输出格式

Question

我需要写一个工具，从iwlist扫描中提取加密类型。但是我找不到一个标准的输出格式。网上搜索了一下，发现大家发布的格式稍微有点不同，我也搞不清楚是复制粘贴错了，还是怎么回事。具体来说，在Encryption key: On中，On和Off的首字母总是大写吗？还有IE: IEEE 802.11i/WPA2 Version 1呢？加密类型前面总是会有IEEE 802.11i/吗？

我希望在这里问这个问题是可以的。

Answer 1

因为 /proc/net/wireless 只是显示当前无线网络连接的信息，所以我调整了一个脚本，让它包含一些加密信息，这些信息是用来给 wpa_supplicant 使用的：

#!/bin/bash
while read line; do

    ## Reset variables on new network
    [[ "$line" =~ Cell || "$line" == "" ]] && {

        # If no WPA encryption info was found though "Encryption" was "On", then we have WEP
        [[ "$encryption" == "" && "$enc" =~ On ]] && encryption = "WEP"

        # If we already found one network then echo its information
        [[ "$network" != "" ]] && echo "$network [$encryption]"
        network=""
        encryption=""
    }

    ## Test line content and parse as required
    [[ "$line" =~ Address ]] && mac=${line##*ss: }
    [[ "$line" =~ \(Channel ]] && { chn=${line##*nel }; chn=${chn:0:$((${#chn}-1))}; }
    [[ "$line" =~ Frequen ]] && { frq=${line##*ncy:}; frq=${frq%% *}; }
    [[ "$line" =~ Quality ]] && {
        qual=${line##*ity=}
        qual=${qual%% *}
        lvl=${line##*evel=}
        lvl=${lvl%% *}
    }

    ## Encryption is "On" if WEP or WPA, otherwise it's "Open"
    [[ "$line" =~ Encrypt ]] && enc=${line##*key:}
    [[ "$enc" =~ Off ]] && {
        [[ "$encryption" != "" ]] && encryption="${encryption},"
        encryption="${encryption}Open"
    }

    ## The ESSID is the last line of the basic channel data, so build information string now
    [[ "$line" =~ ESSID ]] && {
        essid=${line##*ID:}
        network="$mac  $essid  $frq  $chn  $qual  $lvl  $enc"  # output after ESSID
    }

    ## WPA encryption information
    [[ "$line" =~ WPA ]] && wpa=${line##*WPA} && {
        [[ "$encryption" != "" ]] && encryption="${encryption}|"
        encryption="${encryption}WPA$wpa"
    }
    [[ "$line" =~ "Group Cipher" ]] && encryption="$encryption,${line##*: }"
    [[ "$line" =~ "Pairwise Cipher" ]] && encryption="$encryption,${line##*: }"
    [[ "$line" =~ "Authentication Suites" ]] && encryption="$encryption,${line##*: }"

done < <(iwlist wlan0 scan 2>/dev/null )

这个脚本的输出（示例）：

34:81:C7:EB:24:89  "cyberdyne"  2.462  11  67/70  -43  on [WPA2 Version 1,CCMP,CCMP,PSK]
36:81:C7:EB:24:89  "cyberguest"  2.462  11  65/70  -45  on [WPA2 Version 1,TKIP,CCMP,PSK|WPA Version 1,TKIP,TKIP,PSK]

如果某个无线网络名称（SSID）有多种加密方式可用，它们会用 "|" 来分隔。

Answer 2

根据你的需求，直接解析 /proc/net/wireless 的内容可能会更好。这个链接可以帮助你入门。里面的字段都是一样的，但不同的驱动程序和设备的数值可能会有所不同。所以，不要指望拼写会保持一致，大小写就更不靠谱了。