Input/output redirection
Wildcard characters (metacharacters) for filename abbreviation
Shell variables for customizing your environment
Integer arithmetic
Access to previous commands (command history)
Command-name abbreviation (aliasing)
A built-in command set for writing shell programs
Job control
Command-line editing and editor commands
Word completion (tab completion)
Spellchecking
Scheduled events, such as logout or terminal locking after a set idle
period and delayed commands
Read-only variables
