Download - Rich Simms

CIS 90 - Lesson 12
Using Environment (exported) Variables
• Environment variables are a special subset of the shell variables.
• Environment variables are shell variables that have been exported.
• The env command will display the current environment variables and their
values. Using the export command with no arguments will also show all
the environment variables.
• The export command is used to make a shell variable into an environment
variable.
dog=benji; export dog
or export dog=benji
• The export -n command is used to make an environment variable back
into a normal shell variable. E.g. export -n dog makes dog back into a
regular shell variable.
•
Child processes are provided copies of the parent's environment
variables.
•
Any changes made by the child will not affect the parent's copies.
91