Some awesome tips and resources for smartly using shell. This are collected from here and there on internet. Basically it is for my own future reference as I forgot all the times :p

ShellNinja.sh

# ------------[ Shortcuts ]--------------
# tab           => Complete argument
# ctrl+w        => Delete last (w)ord
# ctrl+u        => Delete whole line
# ctrl+k        => Delete from cursor to end of line (kill)
# ctrl+a        => Cursor back to start of line
# ctrl+l        => C(l)ear Screen
# ctrl+r        => Sea(r)ch for previous command
# ---------------------------------------

# Alias for previous command:  !!
# For example re-input previous command with sudo:
sudo !!

# Last specific command: !command
# For example this will run the last `cat` command you used
!cat
# If you just want to see, not run..
!cat:p
# ..then you sure you'll run it, you can go !!
!!

# Argument of last command: !$
# For example:
mkdir some_dir
cd !$

# Go back to previous directory with a dash '-'
cd -

# Fix/replace previous command: ^
# Note: replaces only first instance found.
# For example, if mistyped `nano some_long...` as `nanp some_long...` in last command, can be fixed like this
^nanp^nano

# See all previous history with a command (or anything)
history | grep nano
# This will list all commands with ids like:
# 381 sudo nano /etc/NetworkManager/nm-system-settings.conf
# 387 sudo nano /etc/rc.conf
# Then you can run one of those by that id
!381

# To keep a command out of history, put a space before command
 nano some_important_file.txt
# -- Note the space before `nano` --

# Expansion: {} , Use braces to expand almost similar arguments or so
# For example: to rename
mv /path/to/file.{txt,xml}
# .. or to backup
sudo cp /etc/rc.conf{,-old}
# .. or restore from backup
sudo mv /etc/rc.conf{-old,}
# .. or something else.. [Note: This command below will create 3 dir: myfolder1, myfolder2, myfolder3]
mkdir myfolder{1,2,3}