Question

在bash脚本中，我试图从命令输出中提取一些数据字段（在我的情况下是iwconfig）。

我想用收集的值创建一个csv文件。像：

Timestamp,BitRate,LinkQuality,SignalLevel,Missed beacon,...
1,270 Mb/s,100/100,-51 dBm,0,...
2,300 Mb/s,90/100,-43 dBm,0,...

字段在iwconfig的输出中用两个空格分隔。如果我可以将IFS变量设置为两个空格，我的问题就可以解决了。但我不知道这是否有效。你会用什么来做？ awk还是sed？

祝你好运

Answer 1

回答你的问题：我会用awk。但是，我可能会使用python和单个regexp来捕获字典中的所有参数。

Bonus：我已经完成了使用gnu的grep在bash中执行你想要的操作（你需要的regexp可能因iwconfig输出依赖于设备而有所不同）：

SLEEP=10 # time to sleep between samples

while true; do # or launch it as a cron task
    TIMESTAMP=$(date +'%s')
    IW=$(iwconfig wlan0)

    # capture each parameter in a variable
    IEEE=$(echo "$IW" | grep -oP '(?<=IEEE ).[^\s]*')
    ESSID=$(echo "$IW" | grep -oP '(?<=ESSID:).[^\s]*')
    BITRATE=$(echo "$IW" | grep -oP '(?<=Bit Rate=)\d+\s.[^\s]+(?=[\s]+Tx)')
    TXPOWER=$(echo "$IW" | grep -oP '(?<=Tx-Power=)\d+\s.*')
    RLL=$(echo "$IW" | grep -oP '(?<=limit:)\d')
    RTSTHR=$(echo "$IW" | grep -oP '(?<=RTS thr:).+(?=[ ]+Fra)')
    FRAGTHR=$(echo "$IW" | grep -oP '(?<=Fragment thr:).+')
    TXPOWER=$(echo "$IW" | grep -oP '(?<=Tx-Power=)\d+ .*')
    PM=$(echo "$IW" | grep -oP '(?<=Management:).*')
    LQ=$(echo "$IW" | grep -oP '(?<=Quality=)\d+/\d+')
    SIGLEV=$(echo "$IW" | grep -oP '(?<=level=).*')
    RXNWID=$(echo "$IW" | grep -oP '(?<=nwid:)\d+')
    RXCRYPT=$(echo "$IW" | grep -oP '(?<=crypt:)\d+')
    RXFRAG=$(echo "$IW" | grep -oP '(?<=frag:)\d+')
    RTERET=$(echo "$IW" | grep -oP '(?<=retries:)\d+')
    RTIMISC=$(echo "$IW" | grep -oP '(?<=misc:)\d+')
    RTMBEAC=$(echo "$IW" | grep -oP '(?<=beacon:)\d+')

    #line
    echo $TIMESTAMP,$BITRATE,$LQ,$SIGLEV,$RTMBEAC,...
    sleep $SLEEP
done

输出示例：

1331848207,54 Mb/s,70/70,-37 dBm ,0,...
1331848217,54 Mb/s,70/70,-35 dBm ,0,...
1331848227,54 Mb/s,70/70,-34 dBm ,0,...
1331848237,54 Mb/s,70/70,-39 dBm ,0,...
1331848247,54 Mb/s,70/70,-35 dBm ,0,...
1331848257,54 Mb/s,70/70,-37 dBm ,0,...

Answer 2

我认为这可行：

  s=$(iwconfig $Interface)
  s=${s//          /  }
  s=${s//  /,}
  OIFS="$IFS"
  IFS=','
  arrIN=(${s//  /,})
  IFS=$OIFS

  for value in "${arrIN[@]}"; do
    echo Value: $value
  done

我得到了这个输出：

Value: wlan0
Value:
Value: IEEE 802.11abgn
Value: ESSID:"Top Gear"
Value:
Value: Mode:Managed
Value: Frequency:2.452 GHz
Value: Access Point: F8:D1:11:71:56:B6
Value:
Value: Bit Rate=1 Mb/s
Value: Tx-Power=15 dBm
Value:
Value: Retry
Value: long limit:7
Value: RTS thr:off
Value: Fragment thr:off
Value: Encryption key:off
Value: Power Management:off
Value: Link Quality=49/70
Value: Signal level=-61 dBm
Value:
Value: Rx invalid nwid:0
Value: Rx invalid crypt:0
Value: Rx invalid frag:0
Value: Tx excessive retries:0
Value: Invalid misc:0
Value: Missed beacon:0

现在我可以用例如

直接创建我需要的行

${arrIN[6]#*":"}

使用bash从命令输出中提取数据字段

2 个答案: