how to change "open with" defaults via command line?!?

As a pointer to where to look further, the man page for open mentions:

If no application name is specified, the default application as determined via LaunchServices is used to open the specified files.

If someone cracks this one, please post the answer.

It might be easily done if Property List Editor were scriptable. This might be a question for the AppleScript forum.

Hi David,
That's some nice research. As a matter of further interest, your personal preferences for LaunchServices are stored in the file, ~/Library/Preferences/com.apple.LaunchServices.plist. This file is XML, which is plain text. It can be edited with any text editor, UNIX or otherwise, although the editor cannot insert any formating into the file. Of course, as you've learned, the "defaults" command will also write to that file.

On the other hand, what to put in that file is another matter altogether. To my knowledge, Apple hasn't documented the interpretation LaunchServices makes of the entries in that file. We've figured out some stuff about the old syntax. For instance in the top level key for each "entry", an "E:" precedes the filename suffix for which the preference applies. Someone even figured out how the LSBundleLocator data was encoded. I think it was base64. Fortunately the new syntax is much simpler and contains no data keys. All keys in the new syntax are strings. I haven't studied the new syntax but you don't have to know everything.

Of course you don't necessarily have to produce the information from scratch; there's lots already in the file. For instance, if you copy one entry and paste it back in below, then change the filename suffix to which it applies, you will have created a new preference that would cause files whose name ends with that suffix to be opened by the same application as the original entry.

The defaults command can insert data in this file but it is difficult to make it write deep entries. One way I've found to do this is to write an entire entry at once. You can use a notation like the output of the defaults command or you can pass it raw XML. Because I know XML, I prefer the latter but you have a choice. As an example, on my machine the following command will insert an entire entry:

defaults write com.apple.LaunchServicescopy LSPrefsBindings -dict-add 'C:CARO;T:PDF' '<array>
<dict>
<key>LSBundleIdentifier</key>
<string>com.adobe.acrobat.reader</string>
<key>LSBundleLocator</key>
<data>
AAAAAADaAAMAAAAAt0av6gAASCsAAAAAAAn0MAAJ9CQA
ALmskYAAAAAAASD//kFQUExDQVJP/////wABABAACfQw
AAn0LgABTAQAAASwAA4AJgASAEEAYwByAG8AYgBhAHQA
IABSAGUAYQBkAGUAcgAgADUALgAwAA8ACgAEAEcAYQBy
AHkAEgBFQXBwbGljYXRpb25zL0Fjcm9iYXQgUmVhZGVy
IDUuMC5hcHAvQ29udGVudHMvTWFjT1MvQWNyb2JhdCBS
ZWFkZXIgNS4wAAATAAEvAP//AAA=
</data>
<key>LSBundleRoleMask</key>
<integer>-1</integer>
<key>LSBundleSignature</key>
<string>CARO</string>
<key>LSBundleVersion</key>
<integer>329215</integer>
</dict>
</array>'

That entry should cause PDF files to be opened by Acrobat Reader, at least on my machine. It would be interesting to know if the same LSBundleLocator would work on other machines but that's a good reason to learn the new syntax.

There's another important thing I don't know. That is how to make the changes take effect. Certainly they would take effect after a reboot and person preferences should take effect when you logout and log back in. However, there's probably a way to make the changes take effect more quickly and if someone figures that out, please post it.
--
Gary
~~~~
Don't assume that every sad-eyed woman has loved and
lost -- she may have got him.

From the razor's link:

<pre>

/System/Library/Frameworks/ApplicationServices.framework/\
Frameworks/LaunchServices.framework/Support/lsregister \
-kill -r -domain local -domain system -domain user

</pre>

Hi David,
Sorry, I should have known you'd have written to it with the "defaults" command. The file is now in binary format. There are also other reasons for it to be so but it doesn't really matter; it's a simple matter to convert it to text. The following command will do that for you.

plutil -convert xml1 ~/Library/Preferences/com.apple.LaunchServices.plist

Please note that this is all one line, no matter how the browser or terminal wraps it.
--
Gary
~~~~
A holding company is a thing where you hand an
accomplice the goods while the policeman searches you.

It was in reply to Gary's question:

There's another important thing I don't know. That is how to make the changes take effect. Certainly they would take effect after a reboot and person preferences should take effect when you logout and log back in. However, there's probably a way to make the changes take effect more quickly and if someone figures that out, please post it.

Hi David,
OK, I investigated the new format and treatment. It appears that the first entry in the property list file that matches the file being opened wins. The Finder may still honor the new format; when I moved my old Panther file into Tiger it seemed to work. However, in other ways, the Finder doesn't recognize the old format, which is the format of the FileMaker entries you posted.

The Finder puts all of the new format entries at the beginning of the property list file. If you change a preference that was controlled by an old format entry, the Finder won't edit that entry. What it will do is to create a new entry in the new format closer to the beginning of the file than any of the old-format entries. SInce the new entry comes first, the old one doesn't apply. If you then edit the preference and change it back to what it was before, the Finder will edit the new entry. Consider the following sequence of events and commands:

% cp ~/Library/Preferences/com.apple.LaunchServices.plist ~/Library/Preferences/com.apple.LaunchServices_copy.plist

I change all GIF files to be opened by GraphicConverter instead of Preview, which is an old setting in the old format.

% plutil -convert xml1 ~/Library/Preferences/com.apple.LaunchServices.plist
% diff --text ~/Library/Preferences/com.apple.LaunchServices.plist ~/Library/Preferences/com.apple.LaunchServices_copy.plist
404,409d403
< <dict>
< <key>LSHandlerContentType</key>
< <string>com.compuserve.gif</string>
< <key>LSHandlerRoleAll</key>
< <string>com.lemkesoft.graphicconverter</string>
< </dict>

Then I change all the GIF files to be opened by Preview again.

% plutil -convert xml1 ~/Library/Preferences/com.apple.LaunchServices.plist
% cp ~/Library/Preferences/com.apple.LaunchServices.plist ~/Library/Preferences/com.apple.LaunchServices_copy2.plist
% diff --text ~/Library/Preferences/com.apple.LaunchServices.plist ~/Library/Preferences/com.apple.LaunchServices_copy.plist
404,409d403
< <dict>
< <key>LSHandlerContentType</key>
< <string>com.compuserve.gif</string>
< <key>LSHandlerRoleAll</key>
< <string>com.apple.preview</string>
< </dict>
% diff --text ~/Library/Preferences/com.apple.LaunchServices.plist ~/Library/Preferences/com.apple.LaunchServices_copy2.plist
408c408
< <string>com.apple.preview</string>
---

<string>com.lemkesoft.graphicconverter</string>

Note that I had to change the file to text after every change because the Finder converted the file to binary format every time it edited it. I didn't have to logout or reboot; the property list file change less than a second after the preference was set. I'm guessing that because you were just looking at the old-format entry, you missed the real changes to your property list file. Did it change from text to binary format? Try the command line tools that I used above.

Note that this means that it matters where you put your entries in the property list file if you edit it.
--
Gary
~~~~
There are only 10 kinds of people in the world. Those
who understand binary numbers and those who don't.

Hi David,

> #1) ... Doesn't one need to change the

original before running a comparison?

Of course. Maybe you missed the changes as they are not done in the command line. The changes are made in the two sentences beginning with:

[Then] I change all ...

There is a "cp" command prior to each of the above changes and the correspond "diff" comes after.

> #2) the numbers in your code are foreign to me:

This is a problem with the fact that the browser wraps the lines so it's hard to tell when a line is actually a new line or a wrap from the previous. The numbers are the first line of the output of the "diff" command. The ones you posted basically say that lines 404-409 are in the original file but not the copy. That indicates that those lines were inserted by the Finder when I changed the "open with" preference.

> lastly, as for your question that i

needed to change from binary to text: i don't need to.

That's the most worrisome information. Either your machine doesn't work like mine, you're not actually changing the "open with" preference globally or you're looking at the wrong file. Are you aware of the fact that the tilde, '~', in a UNIX path refers to your home directory? You posted the correct UNIX path to the file but I suppose you could still be unable to find the file in the Finder.

There's one way to find out what file you are modifying, if any. If the file is in your home directory and you run the command below immediately after making a global change to one of the "open with" preferences, the command below should find the file that was modified by LaunchServices. (and possibly other files) This command finds every file in your home directory that was modified less than 5 minutes before the command is run.

find ~ -newermt "5 minutes ago"

It might find numerous files but only one should be a com.apple.LaunchServices.plist property list file. If you don't find anything pertinent with the above command, try the one below.

sudo find / -newermt "5 minutes ago"

This will search your whole drive. If you still don't find a com.apple.LaunchServices.plist file then your machine is behaving completely differently from mine and my advice won't mean much. In fact, I wouldn't have a clue as to how to make the system behave that way.
--
Gary
~~~~
Use common sense in routing cable. Avoid wrapping coax around sources of strong electric or magnetic fields. Do not wrap the cable around flourescent light ballasts or cyclotrons, for example.
-- Ethernet Headstart Product, Information and Installation Guide,
Bell Technologies, pg. 11