how to 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

Try the following:

grep -e "^$" -v foo.txt

The -e option allows regex patterns for matching.

UPDATE: This works for me for a file with blank lines or white spaces on windows:

egrep -v "^[[:space:]]?$" foo.txt

Answer 2

I prefer using egrep, though in my test with a genuine file with blank line your approach worked fine (though without quotation marks in my test). This worked too:

egrep -v "^(\r?\n)?$" filename.txt

Answer 3

Tried hard but this seems to work (assuming \r is biting you here)

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

Answer 4

$ dos2unix file 
$ grep -v "^$" file

Or just simply awk

awk 'NF' file

If you don't have dos2unix, then you can use tools like tr

tr -d '\r' < "$file" > t ; mv t "$file"