How to insert text from a file into another in bash

Question

The content in fileA is:

Here’s the ip list.

ip: 2.2.3.4
ip: 2.2.3.5
ip: 2.2.3.6
ip: 2.2.3.7

The content is fileB is

ip: 1.2.3.4
ip: 1.2.3.5
ip: 1.2.3.6
ip: 1.2.3.7

How to use sed command or other commands in a bash script to produce a list below?

Here’s the ip list.

ip: 1.2.3.4
ip: 1.2.3.5
ip: 1.2.3.6
ip: 1.2.3.7

ip: 2.2.3.4
ip: 2.2.3.5
ip: 2.2.3.6
ip: 2.2.3.7

'cat fileA fileB' would only append fileB to fileA. If I insert a keyword into fileA first and then replace the keyword with fileB's text, all lines from fileB's text would combine into one line when being assigned to a variable.

t=$(cat fileB) 
sed '/[keyword]/c\$t' fileA

Re your edit: No one "abused his power". Your question is hard to understand, so two users (which might be entirely different from those who close-voted it) downvoted it. Write better questions that are clearly topical and this won't happen. See the [help] and [How to ask better questions on Serverfault](http://meta.serverfault.com/questions/3608/how-can-i-ask-better-questions-on-server-fault) — Sven, Dec 07 '14 at 09:09

score 1 · Answer 1 · answered Dec 06 '14 at 02:46

1

Unless I misunderstand, how about you append

cat filea >> fileb

You can do a sort afterwards, if that's what you're after.

answered Dec 06 '14 at 02:46

Hyppy

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There are lines that need to keep at the top in fileA. It could be more than one line that need to be at the top. – Purres Dec 06 '14 at 03:13
So... cat fileb >> filea – Hyppy Dec 06 '14 at 03:31

How to insert text from a file into another in bash

1 Answers1