Utilities for working with parameters and variables

• declare - Declare variables and set attributes
• export - Set export attribute for variables
• local - Assign a local variable in a function
• printenv - Display values of environment variables
• readonly - Set read-only attribute for variables
• set - Set or unset options and positional parameters
• shift - Shift positional parameters
• typeset - Declare variables and set attributes
• unset - Unset values of variables and functions