Apple AppleScript Finder Guide - Manual (Page 130)

C H A P T E R 3
Finder Commands
118
Command Definitions
Exists 3
An Exists command is a request to determine whether the object specified by a
reference exists. The Finder version of the Exists command is identical to the
standard version described in the AppleScript Language Guide.
SYNTAX
exists referenceToObject
referenceToObject exists
PARAMETER
referenceToObject
A reference to the object to find or a list of references.
Class: Reference or list of references
RESULT
A Boolean value. If true, all of the objects referred to by referenceToObject exist.
If false, one or more of the objects referred to by referenceToObject do not exist.
EXAMPLE
This script checks whether a disk named Storage is mounted and, if it is, copies
all files from the folder Correspondence whose modification dates are more
than 30 days old to disk Storage and deletes the originals.
tell application "Finder"
if exists disk "Storage" then
set aMonthAgo to (current date) - (30 * days)
copy (every item in folder "Correspondence" of startup disk ¬
whose modification date < aMonthAgo) ¬
to folder "Old Letters" of disk "Storage"
delete (every item in folder "Correspondence" of startup disk ¬
whose modification date < aMonthAgo)