vi Tip of the day!

Something that I need to do frequently is to set some text to lowercase in vi which is currently in mixed or upper case. A quick way to do this is:

:1s/\(.*\)/\L\1/

The above command acts on line 1 in the file, takes the entire line, enclosed in parentheses to create a group, then uses \L to specify lowercase on the entire line \1 that was previously matched.