Print specific line numbers sed

Print lines matching pattern sed -n '/ERROR/p' app.log Insert line before match sed '/^server_name/i # Added by deploy script' nginx.conf Append line after match sed '/^\[defaults\]/a ansible_python_interpreter=/usr/bin/python3' ansible.cfg Case-insensitive substitution sed 's/error/ERROR/gI' file.txt Multiple expressions sed -e 's/foo/bar/g' -e 's/baz/qux/g' file.txt