vi tips

To format text removing line wraps:
!}fmt

To mark/delete/paste blocks:

• At the beginning of the block: ma [mark a]
• At the end of the block d'a/y'a [delete till a, yank till a]
• To paste the block: p/P

To change everything from upper to lowercase:
%s/.*/\L&/
To search and replace "text1" with "text2" throughout the file:
1,$s/text1/text2/g