SHELL

vim how to append to every line

# Basic syntax:
:%s/$/text_to_add/g

vim append to end of all lines

# append character "*" at the end of each line
:%norm A*

vim insert text before every line

:%s!^!//!

vim insert text before every line

:'<,'>s!^!//!

vim append to line

To append to a line in vim, press A