tures 65 6.1 Invoking Bash 65 6.2 Bash Startup Files 67 6.3 Interactive Shells 69 6.3.1 What is an Interactive Shell? 69 6.3.2 Is this Shell Interactive 69 6.3.3 Interactive Shell Behavior 69 6.4 Bash Conditional Expressions 70 6.5 Shell Arithmetic 72 6.6 Aliases 73 6.7 Arrays 74 6.8