Recently I had a need to count the number of empty lines in a text file. After some digging into the man pages of grep I was able to come up with a one liner which was able to do it.
Following my tradition of documenting one liners, I am going to document this one as well 🙂
Assumption
By empty line, I mean any line which either has no characters or has only whitespace (space, tab) characters.
Command
For the impatient in you, here is the actual command.
Explanation
-P '\S'– This selects all lines that have a non whitespace character-c– Print the count of matching lines-v– Select only the non-matching lines
So, we are first matching all lines that have a non whitespace character and then use -v option to ignore them and then -c option to print the count instead of the actual line.
If we wanted the count of all non-empty lines, then we just have to remove the -v option from the above command.
Hope this is helpful. Happy Grep’ing 😉