An environment variable can be set and exported in the Korn shell with a single command. To set the EDITOR variable to vi, use:
export EDITOR=vi
This command can be placed in ~/.profile to be executed automatically at login, placed in a shell script, or executed manually. Exporting a variable makes it available to other shells spawned from the current shell as when running another command or shell script.
To add to an existing variable, such as path, use this format:
export PATH=$PATH:/usr/local/bin
