Scott Klarr brought together the ultimate collection of leaves pump (cheat sheets) for Linux / Unix.
There's something for everyone: Shell, Solaris, Debian / Ubuntu pakages Management, Unix, Bash, Awk, Ed, Sed, and finally Emacs Vi / Vim.
Examples under Ubuntu:
Disk space avaialble:
df-h
Find files modified today:
find. -Mtime [...]