name="John" echo "${name}" echo "${name/J/j}" #=> "john" (substitution) echo "${name:0:2}" #=> "Jo" (slicing) echo "${name::2}" #=> "Jo" (slicing) echo "${name::-1}" #=> "Joh" (slicing) echo "${name:(-1)}" #=> "n" (slicing from right) echo "${name:(-2):1}" #=> "h" (slicing from right) echo "${food:-Cake}" #=> $food or "Cake"#!/bin/bash string="Hello, World!" uppercase_string=$(echo "$string" | tr '[:lower:]' '[:upper:]') echo "$uppercase_string"