Question

我已声明了两个含有以下内容的变量：

$ echo "$variable1"
Counter values:
out = 323423    in = 7898
counter1    IN= 34    OUT= 232
counter2    IN= 3    OUT= 3
counter555    IN= 2    OUT= 0
counter3    IN= 1232    OUT= 13212
$ echo "$variable2"
Counter values:
out = 323499    in = 7998
counter1    IN= 34    OUT= 238
counter2    IN= 3    OUT= 3
counter555    IN= 2    OUT= 0
counter3    IN= 4248    OUT= 13712
$

我想从第二个变量中的计数器值中减去第一个变量中的计数器值，即最终结果需要如下所示：

$ echo "$variable3"
Counter values:
out = 76    in = 100
counter1    IN= 0    OUT= 6
counter2    IN= 0    OUT= 0
counter555    IN= 0    OUT= 0
counter3    IN= 3016    OUT= 500
$

第二个变量中的整数始终＆gt; =与第一个变量中的整数进行比较。使用bash，awk和sed执行此操作的最优雅方法是什么？我应该使用bash数组吗？我想我这次应该看看awk？如果可能的话，我想避免使用静态位置，并将计数器值与正则表达式（" [0-9]+"）匹配。

Answer 1

paste -d $'\n' <(printf %s "$variable1") <(printf %s "$variable2") | 
  awk '
    !/= [0-9]/ {getline;print;next}  # pass through lines that contain no numbers
    {
      split($0, refLineFields) # split the 1st line of each pair into fields
      getline                  # read the 2nd line of the pair (into $0)
      for (i=1;i<=NF;++i)      # loop over all fields
          # Replace numerical fields with the difference between
          # their value and the one from the corresponding line,
          # Note that assigning to a field causes the input line to be recomposed
          # so that $0 then contains the _modified_ line.
        if ($i ~ "^[0-9]+$") $i=$i - refLineFields[i]
      # Output the modified line.
      print
    }
    '

注意：这会将多个相邻的空格压缩为一个。

使用paste合并两个字符串，以便相应的行在单个输出字符串中相互跟随。
然后awk程序解析行对并执行算术运算;看到来源评论。

从其他变量中的整数中减去一个变量中的整数

1 个答案: