Remove blank lines with grep

Question

I tried grep -v \'^$\' in Linux and that didn\'t work. This file came from a Windows file system.

Answer 1

I tried hard, but this seems to work (assuming \r is biting you here):

printf "\r" | egrep -xv "[[:space:]]*"

Answer 2

Use:

grep pattern filename.txt | uniq

Answer 3

It's true that the use of grep -v -e '^$' can work, however it does not remove blank lines that have 1 or more spaces in them. I found the easiest and simplest answer for removing blank lines is the use of awk. The following is a modified a bit from the awk guys above:

awk 'NF' foo.txt

But since this question is for using grep I'm going to answer the following:

grep -v '^ *$' foo.txt

Note: the blank space between the ^ and *.

Or you can use the \s to represent blank space like this:

grep -v '^\s*$' foo.txt