Match empty lines and commented lines using grep

An example of a configuration file with many commented lines is /etc/sysctl.conf. If you wanted to display the contents of the file without the commented lines, the following command may be issued.

grep -v '^#' /etc/sysctl.conf

However the resulting contents will be displayed with the remaining blank lines.

To get around this one of a couple of commands may be issued.

grep -v '^#' /etc/sysctl.conf | awk 'NF' 
grep -v '^#\|^$' /etc/sysctl.conf