Question

I wish to append ” dddd” to the next line whenever I encounter “=” in a textfile.

This command

sed -i '/=/s|$| dddd|' *.krn

is close to what I am looking for as it appends to the current line where “=” is. How can I append to the next line instead?

Answer 1

Use append, see here:

• http://www.grymoire.com/Unix/Sed.html#uh-40

E.g.:

$ echo $'abc\ndef\ne=f\nqqq'
abc
def
e=f
qqq
$ echo $'abc\ndef\ne=f\nqqq'|sed '/=/adddd'
abc
def
e=f
dddd
qqq

Edited to clarify as per comment from @je4d- if you want to append to what is present in the next line, you can use this:

$ echo $'abc\ndef\ne=f\nqqq\nyyy'
abc
def
e=f
qqq
yyy
$ echo $'abc\ndef\ne=f\nqqq\nyyy'|sed '/=/{n;s/$/ dddd/}'
abc
def
e=f
qqq dddd
yyy

See here for a great sed cheatsheet for more info if you want:

• http://www.catonmat.net/download/sed.stream.editor.cheat.sheet.txt