You can use ^ to match beginning-of-line, and $ to match end-of-line, thus the regular expression ^$ would match an empty line/string.
1 year 7 weeks ago 
You can use ^ to match beginning-of-line, and $ to
You can use ^ to match beginning-of-line, and $ to match end-of-line, thus the regular expression ^$ would match an empty line/string.