Why does the following Applescript, if run repeatedly, keep adding
occurrences of TextEdit to my Dock? My interpretation of manual for
defaults
leads me to believe that duplicate entries would not result from
such a
command.
The only workaround I've found is to search for the entry first, then
not add it if it's found. Thanks.
The problem is that you're one level lower than you think. (Maybe.
See the second paragraph.) The top level of the "defaults" domain is
a key-value dictionary, so, for instance, you could never get two
entries named "persistent-apps". However, what you're doing is adding
an item to an array value, which is perfectly capable of adding
anything regardless of the existing contents of the array.
Reading the man page myself, I see this possibly confusing sentence in
the description of "-array-add":
If the key was not present, it is created with the specified array as
its value.
What that means in your case is that if there is no "persistent-apps"
key, then it will make it using the array you gave -- in other words,
adding stuff to a non-existent array is ok; it's as if the array was
there, but empty. It does *not* mean that it checks the array
contents for a duplicate item.
