Amanda Amanda@Work.Place Version 3.xx, Руководство по установке

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78 Installing Amanda@Work.Place
When most people think of a program, they think of a series of lines, each of which
contains a single action or command. The Token Programming Language is similar, but
each line become the contents of a different field, using the Extension field of a mailbox.
If the program contains only a few lines, sometimes you can use just one Extension or
Method field for the entire program. However, when you need more fields, you use the
Extension fields from additional mailboxes. Even if a Method field must be extended, you
extend it to the Extension field in another mailbox.
You use additional fields for any of the following reasons:
• The logic of the program branches or repeats. You use a G() command or I() com-
mand to create the branch or loop. See “Flow of Control: Branching and Looping”
on page 85 for more details.
• The length of the string of tokens exceeds 65 characters, so you are forced to con-
tinue in another field. You use a G() command to extend the token string to a new
Extension field.
Mailbox Settings
If you are using a mailbox’s Extension field for token programming, you must use all of
the following settings:
• Do Not Disturb must be off. Amanda ignores the Extension field altogether if Do
Not Disturb is on.
• Call screening must be off.
Success and Failure
Amanda evaluates tokens from left to right. If Amanda performs a token successfully, she
goes on to the next token.
When all the tokens have been performed successfully in an Extension field, Amanda goes
to the RNA Chain field. If the RNA field is blank, she goes to the Done Chain field for the
company greeting mailbox (usually mailbox 990).
When all the tokens have been performed successfully in the Notify Method field,
Amanda goes to the next Notify Method field (if there is one). If there are no more Notify
Method fields, Amanda goes to the Done Chain field for the current mailbox.
If the token is unrecognized (because of a syntax error or a typographical error) or fails,
Amanda immediately goes to the Done Chain field without processing the rest of the
tokens in the field. If the last successful token gives Amanda an invalid mailbox, she
processes the Done Chain field for the mailbox associated with the current port because
she cannot locate a Done Chain field for the invalid mailbox. (The mailbox associated
with the port is usually 990, the Company Greeting mailbox.)
For a literal or system variable, there is no such thing as failure. The token always
succeeds. Some tokens define almost any behavior as successful. For example, you can
have Amanda spell an empty string. Amanda doesn’t say anything, but no failure occurs
either.