sed: How to insert before and after every line?

Question

I'm trying to figure out how to insert text before and after every line in a text file using sed on OS X, but something is obviously wrong with my approach.

This is what I have:

sed 's/\(^\).\($\)/A \1\2 Z/g' input

This is what I want:

input:

bbb

ccc
ddd

output:

A bbb Z

A ccc Z
A ddd Z

EDIT: Also, don't match blank lines (or those containing only spaces).

Answer 1

You can use:

sed 's/.*/A & Z/' file
A bbb Z
A ccc Z
A ddd Z

& is back-reference of complete match in regex pattern.

Or using awk:

awk '{print "A", $0, "Z"}' file

Answer 2

You could use:

sed 's/.*/A \0 Z/' input

• .* will match the full line
• \\0 will past the full thing from the first expression