replacing newline sed [duplicate]

Question

How to replace \n from a line using sed command?

Answer 1

It's gross, because sed normally processes a line at a time:

sed -e :a -e N -e 's/\n/ /' -e ta input.txt

This is nicer:

tr '\n' ' ' < input.txt

I chose to replace the newline with a space. tr can only replace by a single character (or delete with the -d option).

Flexible and simple:

perl -ne 'chomp;print $_," "' input.txt

Where " " is whatever you want in place of the newline.