UNIX for Dummies Questions & Answers

I'm attempting to append a line after a specific address with sed. If I type in the address eg.3 then it will append after the third line. I can't get it to work with a variable though. Does anyone know how to do it please?

sed '/3/a\
text' filename

sed '/\$address/a\
text' filename

use " instead of '

Afraid not; it gives me this error message if I replace ' with "

sed: -e expression #1, char 10: Extra characters after command

You need a closing / before the closing double quote

sed -e "s/$address/text/" filename

Nope, still no result.

Replacing the single quotes will work given the requirement is as vgersh and sssow are understanding it. Try posting some sample data.

file1 is four lines "line 1, line 2, line 4, line 5"

I want to introduce a new line.

For example, this works:

sed '/2/a\
line 3' file1

This doesn't

variable=2
sed "/\$variable/a\
line 3/" file1

Nor this:
sed '/\$variable/a\
line 3/'file1

Nor this:
sed "/$variable/a\
line 3" file1

I've tried various combinations of " ' \ / but can't get it to accept the variable.

This is the error it usually come up with:
sed: -e expression #1, char 10: Extra characters after command