如何使用 GREP 检查文件中是否存在两个单词

Question

我有两个文件 A.txt 和 B.txt 分别包含两个列表，如下所示。

文件 A.txt

hello
hi 
ko

文件 B.txt

fine
No 
And how
why

现在我想检查在另一个文件 C.txt 的一行中是否存在任何这些单词（来自 A.txt 和 B.txt）。

我正在使用 grep 命令

grep -iof A.txt C.txt| grep B.txt

C.txt 包含包含 A.txt 和 B.txt 中单词的句子

Hello I am fine
I am not fine
why ko is and how?

不显示任何输出

所以，现在我想如果 A.txt 和 B.txt 中的任何单词同时出现在一个句子中，它应该将输出显示为

Hello fine
why ko and how 

如果两个文件同时出现在 C.txt 中，则只打印匹配的单词，而不是打印 C.txt 中的整行

Answer 1

你可能想说：

$ grep -if B <(grep -if A C)
Hello I am fine
why ko is and how?

这使用-f 来提供表达式。它可以是一个文件...或您使用process substitution <( ... ) 即时创建的文件。

首先，grep -if A C 匹配C 中所有在A 中的单词：

$ grep -if A C
Hello I am fine        # "Hello" highlighted
why ko is and how?     # "ko" highlighted

然后，将其输出与B中的内容进行比较。

$ grep -if B <(grep -if A C)
Hello I am fine        # "fine" highlighted
why ko is and how?     # "and how" highlighted

根据您的需要，您可能需要添加-F、-w 和-i。

来自man grep：

   -f FILE, --file=FILE
          Obtain  patterns  from  FILE,  one  per  line.   The  empty file
          contains zero patterns, and therefore matches nothing.   (-f  is
          specified by POSIX.)

   -F, --fixed-strings
          Interpret PATTERN as a  list  of  fixed  strings,  separated  by
          newlines,  any  of  which is to be matched.  (-F is specified by
          POSIX.)

   -i, --ignore-case
          Ignore  case  distinctions  in  both  the  PATTERN and the input
          files.  (-i is specified by POSIX.)

   -w, --word-regexp
          Select  only  those  lines  containing  matches  that form whole
          words.  The test is that the matching substring must  either  be
          at  the  beginning  of  the  line,  or  preceded  by  a non-word
          constituent character.  Similarly, it must be either at the  end
          of  the  line  or  followed by a non-word constituent character.
          Word-constituent  characters  are  letters,  digits,   and   the
          underscore.