*Automatically invoked when exiting `EDIT.SYSTEM` when using W)rite, F)orward or R)eply in `EMAIL.SYSTEM`*
`ATTACHER.SYSTEM` is used for attaching files to outgoing email messages. This program is started automatically by `EDIT.SYSTEM` and is not normally invoked directly.
When `EDIT.SYSTEM` invokes `ATTACHER.SYSTEM`, the following operations occur:
- The outgoing email message is loaded from `OUTBOX` and copied to a temporary file. While copying, additional email headers are appended to indicate that this is a MIME multi-part message.
-`ATTACHER.SYSTEM` loops until the user says they are done adding attachments:
- Display the current number of attached files. Initially this shows `There are currently 0 attachments`.
- Display a list of the files that have been attached so far.
- Prompt: `A)dd attachment | D)one with attachments`.
- If the user chooses 'D' then we are done adding attachments. Exit the loop.
- If the user chooses 'A' then a file selector is shown, allowing the user to choose the file to attach. Navigate to the desired directory and select the file to be attached. Alternatively, you can hit the `Tab` key and type in the absolute or relative path to the file to be attached.
- The selected file is loaded from disk and encoded using the Base64 algorithm. A MIME section is created in the outgoing email and the Base64-encoded file data is appended.
-`ATTACHER.SYSTEM` will terminate the MIME document, erase the original email file from `OUTBOX` and rename the temporary file to replace the original.
-`ATTACHER.SYSTEM` will reload `EMAIL.SYSTEM` once it is done.
