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カラス avatar Ubuntu

How to save command output to specific line of text file

dk flag
カラス

I would like to know how to save command output to a specific line of a text file.

I searched on the internet for about an hour about this problem, but I didn't find any proper answer.

For example:

I want to save the output of some ls command to 7th line of example.txt. (insert new line)

How would I do it?

Thanks in advance.

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HuHa avatar
es flag
HuHa
This might be what you need: https://unix.stackexchange.com/questions/70878/replacing-string-based-on-line-number
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hr flag
steeldriver
Do you want to overwrite the existing 7th line? or insert the new line before or after it?
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カラス avatar
dk flag
カラス
@steeldriver insert new one
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Score:2
avatar Ubuntu
hr flag
steeldriver

You could use sed's r command to read and insert the command output after a given address. In particular, GNU sed provides the special filename /dev/stdin to read data from standard input.

So for example, given

$ cat example.txt
Line 1
Line 2
Line 3
Line 4
Line 5
Line 6
Line 7
Line 8
Line 9
Line 10

then

$ ls -l example.txt | sed -i '7r/dev/stdin' example.txt

results in

$ cat example.txt
Line 1
Line 2
Line 3
Line 4
Line 5
Line 6
Line 7
-rw-r--r-- 1 steeldriver steeldriver 71 Jun 28 15:52 example.txt
Line 8
Line 9
Line 10

If you want the command output inserted before the 7th line, then read and insert it after the 6th.

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カラス avatar
dk flag
カラス
It works! Thank you so much.
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