Shell Scripting Cheat Sheet

Variables

Command	Description
VAR=value	Define a variable
$VAR	Access a variable
`command`	Command substitution

Flow Control

Command	Description
if	Conditional check
then	Execute if condition is true
else	Execute if condition is false
elif	Alternative condition
fi	End conditional check
for	Loop
while	Loop while condition is true
do	Loop body
done	End loop

Functions

Command	Description
function_name() {}	Define a function
return	Return from a function
$?	Return value of the last command

Script Control

Command	Description
#!/bin/bash	Specify the interpreter used by the script
chmod +x script.sh	Grant execute permission to the script
./script.sh	Execute the script