Set an environment variable. Mark each name to be passed to child processes in the environment.


      export [-fn] [-p] [name[=value]]


      -f   The names refer to shell functions; 
           otherwise the names refer to shell variables
      -n   No longer mark each name for export.
      -p   Display output in a form that can be reused as input.   

If no names are supplied, or if the `-p’ option is given, a list of exported names is displayed.

The return status is zero unless an invalid option is supplied, one of the names is not a valid shell variable name, or `-f’ is supplied with a name that is not a shell function.

export is a bash built in command.

Example – local variables

mv $old_file $new_file
Example – global variables

mydepartment=Sales ; export mydepartment
mycustomer=’Brown Brothers’ ; export mycustomer