We can use grep command for this option. Grep command gives –v option to exclude lines that do not match a pattern.
In an empty line there is nothing from start to end. In Grep command, ^ denotes that start of line and $ denotes the end of line.
% grep –v ‘^$’ lists the lines that are empty from start to the end.
Once we get this result, we can use > operator to write the output to a new file. So exact command will be:
% grep –v ‘^$’ file1.txt > file2.txt