terminal - 如何grep返回结果作为匹配项

Question

我只想返回我用来搜索的术语的第一个实例（不区分大小写）（如果有匹配项），我该怎么做？

例子：

$ grep "exactly-this"

Binary file /Path/To/Some/Files/file.txt matches

我想返回如下结果：

$ grep "exactly-this"

exactly-this

Answer 1

grep 有一个内置的计数参数

您可以使用该-m选项为 grep 提供计数参数

grep -m 1 "exactly-this"

如果要避免出现二进制文件的消息，请使用

grep -a -m 1 "exactly-this"

请注意，这将打印word发生匹配的位置。由于它是二进制文件，因此word可能跨越多行

Answer 2

您需要的-o是grep.

来自man page

 -o, --only-matching
             Prints only the matching part of the lines.

测试：

[jaypal:~/Temp] cat file
This is a file with some exactly this in the middle
with exactly this in the begining
and some at the very end in brackets (exactly this)

[jaypal:~/Temp] grep -o 'exactly this' file
exactly this
exactly this
exactly this

[jaypal:~/Temp] grep -om1 'exactly this' file
exactly this