Bash Commands - Special Charactors # ? $

1. ?

Test operator.

condition?result-if-true:result-if-false

$ (( var0 = var1<98?9:21 ))
#
#
# if [ "$var1" -lt 98 ]
# then
# var0=9
# else
# var0=21
# fi

$ echo $var0

9

2. $

Variable substitution.

A $ prefix a variable name indicates the value the variable holds.

var1=5
var2=23skidoo
echo $var1
echo $var2