Ever wanted to comment out multiple lines of code while writing shell scripts in vi, but didn't want to pound your keyboard for half an hour doing it?
(I#Escape j.j.j.j. = carpal tunnel)
Here's the nerdy way to do it:
Where N-1 is the number of lines minus one that you want to comment out, and s/^/#/g is the regular expression (the pattern between the first two slashes is what you want to replace, in this case the beginning of the line, and the pattern between the last two slashes is what you want to replace it with).
For example, if you're a bad coder like me and want to comment out 500 lines of code, you would do: