If, like mine, your colleagues are constantly moaning about vi when installing their machines, have them read this!

Print the essential commands shown below, stick them on top of the coffee machine and have your coworkers recite them before getting a coffee. After a week, they'll be ready to fix any Linux box with the stock tools, even when lost in the middle of a desert (I must admit I haven't tried the desert bit, but it should work).

Essential commands

ESC

toggles between insert and command mode

h,j,k,l

cursor left,down,up,right

i

insert before cursor position

A

add at end of line

o

open (insert) a line after current line

dd

delete current line

CTRL-F / CTRL-B

page forward / backward

ZZ

quit and save

:q!

quit without saving

Other useful commands (partial list)

w,b

word forward/backward

cw

change word (end with ESC)

x

erase one character

d5d

delete 5 lines from current position

dw

erase one word

yy

copy current line to buffer (yank)

p

paste buffer after current line

CTRL-G

display file information at bottom of screen

3G

go to line 3

/expr

search forward for a regular expression

n

repeat forward search

N

repeat backwards search

:g/word1/s//word2/gc

replace word1 by word2 in the whole file with user confirmation.

:/word1/s//word2/gc

replace word1 by word2 in current line with user confirmation.