####  Chapter 6 demos
cd ~
mkdir x6                # Create subdir ~/x6
cd x6
pwd

printenv HOSTNAME
printenv HOME
printenv USER

printenv PATH
printenv PWD

printenv MANPATH
printenv TERM

echo "CONFIG & ENV variables:"
printenv | more
echo "------------------"
a=5
echo a
echo $a
echo "$a"
echo '$a'
echo `$a`

# Expressions
b=7
let x=$a+$b
echo $x

# Execute
cmd="ls -l"
echo $cmd
echo '$cmd'
echo "$cmd"
echo `$cmd`
echo `$cmd g*`