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

Question

folks,
i know that if i get info on a file -- in this case, a filemaker 5.5 file -- i can choose the default "open with" settings and apply those settings to all files of that kind. see the attached image for what i mean.
but how do i do that via the command line?
thus far, here's what i've got: i know that i can open a document called "scrubbing shell.sh" on my desktop WITH either MS Word of TextEdit by calling:
open -a textedit /Users/david/Desktop/scrubbing-shell.sh
or
open -a Microsoft\ Word /Users/david/Desktop/scrubbing-shell.sh
no sweat. BUT....how do i set the defaults so that it ALWAYS opens with that app in the future when double-clicking via the GUI?
many thanks, ya'll!
david koff
associate systems admin
the j. paul getty trust
dkoff AT getty DOT edu

Answer 1

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.