linux - 我如何根据这两行的单词总和组合两条相邻的行(递归)

Question

仅当两行的单词总和(定义为由空格或行尾符号分隔的连续字符的单词)小于 20 个单词时，我才尝试合并两个连续的行。

示例输入:

1This line has five words.
2This line has unfortunately six words.
3This line has also six words.
4The above three lines have a total of 18 words, which is less than 20, and should be combined into one line.
5This line has only 6 words.

期望的输出:

1This line has five words. 2This line has unfortunately six words. 3This line has also six words.
4The above three lines have a total of 18 words, which is less than 20, and should be combined into one line.
5This line has only 6 words.

我有以下代码作为起点，但我不知道如何设置条件，所以它会检查连续的两行。

awk '{while (sum(NF + NF+1) > 20) {sub ("\n", "")}}1'

两个问题是 while (sum(NF + NF+1) > 20)...我如何让它检查连续两行的总和？第二个问题......出于某种原因 sub ("\n", "") 没有去掉行尾的换行符，即使我在一行中尝试它也是如此。

谢谢。

Answer 1

Awk 逐行读取其输入，不读取它就无法知道下一行中的字段数(单词)。所以，你的逻辑是行不通的。

下面是实现此目的的直接方法；它只是缓冲行，直到字数达到 20，释放缓冲区内容，然后继续。

awk '(c += NF) < 20 {
  buf = (buf sep $0)
  sep = OFS
  next
}
{
  if (NR > 1)
    print buf
  buf = $0
  c = NF
}
END {
  print buf
}' file