Shell

Movement

ALT+F to jump Forward by a word.
ALT+B to jump Backward by a word.
CTRL+F to move forward by a char
CTRL+B to move backward by a char
CTRL+A to jump to start of the line
CTRL+E to jump to end of the line
CTRL+K to kill the line starting from the cursor position
ALT+D to delete a word starting from the current cursor position
CTRL+W to remove the word backwards from cursor position
CTRL+R to reverse search for commands you typed in the past from your history.
CTRL+S to forward search (works in ZSH for me but not bash)

To assign a variable, use = without space
To use a variable, simply add $ before it
set -x Show what’s executed
set -e If the return code of one command is not 0 and the caller does not check it, the shell script will exit. This feature make shell script robust.
$0 - Name of the script
$1 to $9 - Arguments to the script. $1 is the first argument and so on.
$@ - All the arguments
$# - Number of arguments
$? - Return code of the previous command
$$ - Process identification number (PID) for the current script
!! - Entire last command, including arguments. A common pattern is to execute a command only for it to fail due to missing permissions; you can quickly re-execute the command with sudo by doing sudo !!
$_ - Last argument from the last command. If you are in an interactive shell, you can also quickly get this value by typing Esc followed by . or Alt+.