echo $1
	string="I'm a fan of Origami."
	echo ${string:6:3}

	expr 3 + 12

	declare -i number
	number = (2 + 4) * 10

	cat file1 file2 > combined

	exec < file

	this && that

	foo | grep bar
	du -cks * | sort -rn | head

	echo *.txt
	#some comment