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Problems when opening files on Mac

As usual, I cannot be responsible for any damage to your machines when you will experiment the following tutorial.

The problems: a file cannot be opened... or it launches SimpleText...

... or you've made a zip archive of documents through dropzip and the uncompressed files have an SimpleText generic icon.

The source of the problem is that, for a reason or another, you've lost the ressource fork of the file.

The ressource fork helps the Finder to determine which application is to be launched to open a file when you double-click on it.

Most of the times, the lost of this fork arrives when you transfer the file (email, ftp,... ) as it through a PC.

The PC does not know anything about resource fork, so it does transfer it.

Dropzip also ignores this fork and leads to the same problem for documents archives made with this tool.

When the corrupted document refers to data only, it is not a big problem.

However, if the corrupted file is a program... it is lost! :-(.

To demonstrate the problem, I 'dropzip' Mac files.


In a folder, I put 5 files, each of them of a different typed:



The archive of the 5 files.


The archive's contents after being uncompressed.

SimpleText generic icons: the visible part of the problem :-(


ResEdit's info of a file: simple text file


For the Acrobat file, that's what the Type & Creator should be.

-> the solution is quite easy: put back the correct file Type & Creator. With ResEdit, FileBuddy or other programs like Type.

Another solution is to drag the files to their respective application: this application recognizes them and opent it... "all of them" ? Well Quark does not recognize its own file...

-> So the Type/Creator change operation is required here only for Quark.

Ok, ok... my example was easy: I named the files with the application name which should open them.

And now, with a file the name of which means all but not an idea of which application will help us ?

And BBedit comes: just drag the file onto BBedit.

When the file is opened, its identifier appears (more or less clearly, I must confess) in the body of the text.


if the file starts with:
%!PS-Adobe-3.0 EPSF-3.0
It is an Illustrator file:-)

More complicated:

XPR3 in the few starting keywords... -> XPRESS... even if a double-click launches SimpleText.

To allow double-click on such a file, we have to modify the Type & Creator: ResEdit or FileBuddy: the "TEXT" Type and the "ttxt" Creator has to be changed in "XDOC" and "XPR3" respectively.

Within ResEdit, just show the informations of the file and replace the wrong Type & Creator by the correct ones.

Save the file and normally, a simple double-click will launch the original application again.

Good luck...

... but do not forget that a compressed archive can be uncompress when dragin it to the StuffitExpander's icon... simply!

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