OS X File information question

[Jonathan Waddilove]

OS X (tiger) stores some useful information about files, including
"where from" and "spotlight commnets".

Is there an (easy) way to access these fields from Ruby?

Many thanks, Jonathan

 

[Gabriele Marrone]

OS X (tiger) stores some useful information about files, including
"where from" and "spotlight commnets".

Is there an (easy) way to access these fields from Ruby?

Give a look here: http://developer.apple.com/macosx/spotlight.html
Under the "Command-Line tool" section you can find something
interesting.

For example:

piastrella:~/Desktop$ mdls -name kMDItemFinderComment test.txt
test.txt -------------
kMDItemFinderComment = "This is a Spotlight comment."

You could wrap that tool in a Ruby class or something like that.

 

[Frederick Cheung]

It's a little more tricky writing to these: to write a finder comment
(now called spotlight comment, but implementation-wise it's the same)
you need to send an appleevent to the finder (there'a a code sample on
developer.apple.com for this).

To set the where_from, you need to use the undocumented api
MDItemSetAttribute, since in theory meta deta doesn't just get set at
random times, but when the importer for that file is run.
MDItemSetAttribute does however enable you to set metadata at will
(those changes would of course be blown away if the user chose to
reindex their files.

Fred

 

[has]

It's a little more tricky writing to these: to write a finder comment
(now called spotlight comment, but implementation-wise it's the same)
you need to send an appleevent to the finder (there'a a code sample on
developer.apple.com for this).

You can do AEs from C but it's a bit tedious. Much easier with a
high-level bridge, e.g.:

require "appscript"

pth = "/path/to/some file or folder"
txt = "some comment"

AS.app("Finder").items[MacTypes::Alias.path(pth)].comment.set(txt)

Or, if you want to avoid dependencies and speed isn't an issue, you
could just use osascript to invoke an AppleScript via the command line.
Kludgy, but it'll do the job.

If portability is a must though, bear in mind that some OS X users run
third-party file managers in place of the Finder. (Not like the ol' OS
7-9 days when Finder availability was pretty well guaranteed.) I think
there's also some very crusty Carbon APIs for accessing Finder-related
data, though can't remember anything about them. Probably in the Carbon
File Manager or somewhere like that.


For querying files, the OP might also want to check out the Carbon or
Cocoa Spotlight APIs:


http://developer.apple.com/documentation/Carbon/Conceptual/SpotlightQuery/index.html

There's a 'RubySpotlight' example included with RubyCocoa 0.4.2 that
may be of help here.

has

 

[Jonathan Waddilove]

Gabriele, Fred

Thank you both for the help. I'll poke around in the documentation,
first task is to extract the settings in those fields (changing them
from Ruby is later in my game plan)

Many thanks for your help.