Shell-variables

Shell variables are variables that are only applied to the current shell instance.

var=TestVar
echo $var
echo ${var} # long format for expressions in strings

Environment variables

Environment variables are shell variables that are inherited by all system processes. A shell variable can be promoted to an environment variable by exporting it.

export var=TestVar

All current environment variables can be viewed using export

References

• Command-Line-A-modern-introduction