export [-fn] [name[=value] ...] or export -p [-f]
Set export attribute for shell variables.
Marks each NAME for automatic export to the environment of subsequently executed commands. If VALUE is supplied, assign VALUE before exporting.
Options:
-f- refer to shell functions-n- remove the export property from each NAME-p- display a list of all exported variables or functions
An argument of -- disables further option processing.
Exit Status: Returns success unless an invalid option is given or NAME is invalid.