Insert contents of a file after specific pattern m

2019-01-03 10:40发布

问题:

I want to insert file content at specific pattern match. The following is an example: add file2.txt content in file1.txt between <tag> and </tag>.

file1.txt

<html>
<body>
<tag>
</tag>
</body>
</html>

file2.txt

Hello world!!

I have tried following and it didn't work.

# sed "/\<tag\>/ {
h
r file2.txt
g
N
}" file1.txt

<html>
<body>
Hello World!!
<tag>
</tag>
</body>
</html>

回答1:

Try following command:

sed '/<tag>/ r file2.txt' file1.txt

It yields:

<html>
<body>
<tag>
Hello world
</tag>
</body>
</html>

EDIT for explanation why your command doesn't work as you want: The r filename command adds its content at the end of the current cycle or when next input line is read. And you are using the N command which doesn't print anything but reads next line, so at that time Hello world is printed and after that the normal stream of lines.

In my case, it reads line with <tag>, then ends cycle, so prints the line and after it the content of the file and carry on reading until the end.