Bash Shell

Hotkeys

Navigation

CTRL + a move to beginning
CTRL + e move to end

ALT + f move forward by one word
ALT + b move backward by one word

CTRL + n down arrow
CTRL + p up arrow

Text Control

CTRL + k cut after cursor
CTRL + l clear
CTRL + u cut before cursor
CTRL + w cut word before cursor
CTRL + y paste
CTRL + _ undo typing
ALT + r undo changes made to command from history

Misc

CTRL + r backward search
CTRL + g leave search without running a command
CTRL + j copy current matched command to cli without running it
CTRL + s stop output
CTRL + q resume output
CTRL + d escape current shell or delete character under cursor
CTRL + t switch character before cursor with cursor

$_ repeat last argument. Risky in scripts, best use case after &&.

Functions

Single Parenthesis ( ... ) is creating a subshell for nested commands
Double Parenthesis (( ... )) is for arithmetic operation
Single Square Bracket [ ... ] is the syntax for the POSIX test
Double Square Brackets [[ ... ]] is the syntax for conditional expressions (similar to test but more powerful)

Single Ampersand command1 & command2 run command1 in the background
Double Ampersand command1 && command2 run command2 only if command1 succeeded
Single Pipe command1 | command2 use output of command1 as input for command2
Double Pipe command1 || command2 run command2 only if command1 failed

Change to the directory of the script

cd "$(dirname "$(readlink -f "$0")")"
1. readlink -f "$0" determines the path of the current script ($0)
2. dirname converts the path of the script to its directory
3. cd changes the working directory to the directory it receives from dirname