将xargs与cat和grep相结合

Question

我想从一个文件中获取输出，并将其作为grep命令的参数输入到我要对其执行的同一文件中：

:~$ cat example
cat
dog
mouse
ant
:~$ cat example | xargs cat example | grep
Usage: grep [OPTION]... PATTERN [FILE]...
cat: cat: No such file or directory
cat: dog: No such file or directory
cat: mouse: No such file or directory
cat: antTry 'grep --help' for more information.
: No such file or directory

换句话说，预期的命令是：

cat example | grep cat
cat example | grep dog
cat example | grep mouse
cat example | grep ant

Answer 1

您需要像这样将cat example的输出馈送到xargs -I{}，其中{}是参数占位符：

cat example | xargs -n1 -I{} grep {} example