Bash Cheat Sheet

Comparison operators

Operator	Description		Operator	Description
-eq	Is equal to		-n	Is not null
-ne	Is not equal to		-z	Is null
-gt	Is greater than		-r	file exists and is readable by the user
-ge	Is greater than or equal to		-e	file exists
-lt	Is less then		-f	file is a regular file (not directory or other special type)
-le	Is less than or equal to		-s	file size is greater then 0
==	is equal to		-x	file is executable by the user
!=	is not equal to		-w	file is writable by the user
<	Is less than		!	negates the operator
<=	Is less than or equal to
>	Is greater then
>=	Is greater than or equal to

Variables for script arguments

Variable	Description		Variable	Description
$1 ... $n	Argument number		$#	Number of arguments
$0	Name of the file		$?	Return value (0 = ok, > 0 = error)
$*	List of arguments