有没有办法在linux的conf文件中将文本添加到字符串的末尾？

Question

I have a problem: I have a file that, if I knew how, I would like to edit from the command. I would like to locate the file by content on that line.

I am in CyberPatriot, and my team is second in my state. I know someone who is on the number one team and I know one of the people on the first team. It kills me so I want to make a list of commands that I can go off of to make it faster and more efficient.

Imagine I had this file:

example
oof
goo
random
yes

and I wanted to change it to this:

example
oof
goo
random 'added text'
yes

How do I do so? I know I can use the echo command to add text to the end of a file, but I don't know how to add text to the end of a specific line.

Thanks, Owen

Answer 1

You can use sed for this purpose.

sed 's/random/& Hello World/' file

to append text to the matched string.

You can use ^random$ to make sure the entire line is matched, before appending.

If you need to modify the file directly, you can use the -i flag, which facilitates in-place editing. Further, using -i.bak creates a backup of the original file first before modifying it, as in

sed -i.bak 's/random/& Hello World/' file

The original copy of the file can be found in file.bak

More about sed : https://www.gnu.org/software/sed/manual/sed.html

Answer 2

Use something like below

sed '4!d' file | xargs -I{} sed -i "4s/{}/{} \'added text\'/" file

Basically in the above command, we are getting the 4th line of the file using sed sed '4!d' file and then using this line to replace it with the same text and some new text( added text )