does System Events in AppleScript support duplicating files? - applescript

Question

I've been trying to get System Events to duplicate files in AppleScript and I've been failing :) I eventually always get the error "error "Files can not be copied." number -1717". So I changed my tactics and tried using the Finder to make sure what i was trying to do was correct. Here is the code that works:
tell application "System Events"
set desktopFolder to (path to desktop folder) as string
set fullPath to desktopFolder & "Temp Export From DO"
set theDOEntries to every file of folder "/Users/jkratz/Dropbox/Apps/Day One/Journal.dayone/entries" whose name extension is "doentry"
repeat with DOEntry in theDOEntries
set source to path of DOEntry
log "Source file: " & source
set destination to fullPath as string
log "Destination folder: " & destination
tell application "Finder"
duplicate file source to folder destination with replacing
end tell
end repeat
end tell
If I remove that last tell, so that it uses System Events, I get the same error noted above. The dictionary for System Events standard suite has a "duplicate" command so I'm not sure what is going on here. Also, "Learning AppleScript, 3rd ed" from APress notes:
"One particularly annoying omission in System Events is that it can’t yet duplicate files and folders; if you need to do this, the Finder is your best bet."
The 3rd edition is from 2010. It would seem that even in Mountain Lion this is still true. Can anyone confirm this? The 1717 error number lists everywhere else as a handler error and i'm not using handlers.

Answer 1

Unfortunately, you cannot duplicate files using System Events - you have to use the Finder. Even in the answer provided by adayzdone, System Events is not actually handling the duplication.
This looks like it's working (because it's inside a System Events tell block)...
tell application "System Events"
duplicate myFile to myFolder
end tell
...but if you inspect the event log you'll see that the Finder is actually performing the duplication. Behind the scenes, you are passing two Finder objects to System Events. System Events doesn't know how to handle Finder objects, so execution is passed to the objects' owner, the Finder, which executes the command.
For file duplication in AppleScript, you are unfortunately limited to using the Finder or the command line via do shell script.

Answer 2

Try:
tell application "Finder" to set desktopFolder to (path to desktop folder as text) & "Temp Export From DO" as alias
tell application "System Events" to set theDOEntries to every file of folder "/Users/jkratz/Dropbox/Apps/Day One/Journal.dayone/entries" whose name extension is "doentry"
repeat with DOEntry in theDOEntries
log "Source file: " & DOEntry
log "Destination folder: " & desktopFolder
tell application "Finder" to duplicate file DOEntry to desktopFolder with replacing
end repeat
If you don't need to log the values you can simply:
tell application "Finder" to set desktopFolder to (path to desktop folder as text) & "Temp Export From DO" as alias
tell application "System Events" to set theDOEntries to every file of folder "/Users/jkratz/Dropbox/Apps/Day One/Journal.dayone/entries" whose name extension is "doentry"
tell application "Finder" to duplicate theDOEntries to desktopFolder with replacing
Or:
set desktopFolder to quoted form of (POSIX path of (path to desktop folder as text) & "Temp Export From DO")
do shell script "find '/Users/jkratz/Dropbox/Apps/Day One/Journal.dayone/entries' -name \"*.doentry\" -type f -print0 | xargs -0 -I {} cp -a {} " & desktopFolder
Getting back to your question, the duplicate commands creates duplicates of Finder items. You can use System Events to duplicate Finder items like this:
tell application "Finder"
set myFile to file ((path to desktop as text) & "Test File.txt")
set myFolder to folder ((path to desktop as text) & "Test Folder")
end tell
tell application "System Events"
duplicate myFile to myFolder
end tell