Why did Apple abandon TYPE and CRTR?

Discussion in 'Apple' started by jt august, Jun 17, 2007.

  1. jt august

    jt august Guest

    In the classic OS (1.0 to 9.2), back in the daze of System 6.0.5 and
    System 7, files had a Type and Creator attribute that was heads and
    tails over the .SFX suffix of Windows. When Apple went to the Unix
    based OS X, they abandonned this very nice set-up. My question is why?

    jt august, Jun 17, 2007
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  2. jt august

    Jon Guest

    Jon, Jun 17, 2007
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  3. There's no real answer to why they abandoned something when, so far,
    they haven't actually abandoned it. Nor have they really added a new
    alternative, because one of the components of a stock install of Mac OS
    for years prior to OS X was one that would map documents to apps based
    on extension. What they _have_ done is swapped the priority of those two
    mapping mechanisms.
    Gregory Weston, Jun 17, 2007
  4. jt august

    jt august Guest

    The first article was very technical and confusing. The second article
    describes a new typing structure, but says that this only applies to
    some parts of the OS, and that .suffixes are still required for saved

    Neither article explains why Apple chose to move away from TYPE and
    CRTR. And googling has yet to produce an explanation as to why?

    jt august, Jun 17, 2007
  5. jt august

    Jon Guest

    Look at the section titled "Analysis". That says a lot actually.
    Well, the discussion _is_ rather technical as it is a technical subject,
    and the reasons why Apple went the way they did are not entirely clear.
    See, e.g.: <http://arstechnica.com/reviews/os/macosx-10-4.ars/6>, where
    the topic once again is examined, and linked to the more general topic
    of "metadata" (data about data).
    By searching for the following in Google, I got a load of articles and
    hits that ought to be helpful, IMHO:

    type/creator extension "Mac OS X"

    Other searches may be even more successful.

    As I said, I do not think the reasons are entirely clear. Initially it
    was thought that they did it mainly for compatibility with other OS'es.
    However, at least as long as Apple stays with the HFS+ file system and
    its descendants, it seems they can use both.
    Jon, Jun 17, 2007
  6. jt august

    tacit Guest

    They didn't.

    Mac OS X still uses Type and Creator codes. In *addition* to that, it
    *also* uses file name suffixes. You do not *have* to use suffixes if you
    do not want to.

    Apple did not abandon Type and Creator codes. They *added* filename
    suffixes, that's all.

    Why did they do this?

    Simple. Macs can use a wide variety of different disk formats and file
    systems. Some file systems, such as FAT32 and UFS, do not use Type and
    Creator codes. So Macs can use both Type and Creator codes and file
    suffixes to make using files on non-native file systems (and files sent
    through the Internet or other networks) easier.
    tacit, Jun 17, 2007
  7. jt august

    jt august Guest

    Thank you. This explanation makes more sense to me than anything else I
    have found googling, etc. I had been of the conclusion that for os x,
    TYPE and CRTR were only being supported as a bow to clssic, and that
    their days are numbered. If I am understanding you correctly, this file
    option will always be around if the disk is formatted correctly.

    The one thing I liked best about the old way was that a text file made
    by macWrite Pro would launch MWPro if double clicked, and a text file
    made by simpletext would launch simple text if the file was opened.

    jt august, Jun 18, 2007
  8. Only when the sys admin decides he can blow away all those annoying dot
    Gregory Weston, Jun 18, 2007
  9. I don't think they have. For example, when I specify the Creator of a
    "*.pdf" file as "CARO", Finder opens it with Adobe Reader even though
    Preview remains the default for files with the "pdf" filename extension.
    It seems that a per file setting (set via Get Info) receives the highest
    priority, followed by the Creator code, and the filename extension is
    used only when the first two types of metadata are empty.

    The OP might find the shareware preference pane RCDefaultApp useful for
    viewing and editing many Launch Services settings.
    Neill Massello, Jun 18, 2007
  10. There is a per-file setting. That's new to the Mac with OS X and it's
    the highest priority.

    Below that are extensions and creator codes, in that order (on current
    versions of OS X...ISTR that change happened some time after 10.0).
    Prior to OS X, the creator code was supreme and extension was a fallback
    provided by a stock extension.

    Gregory Weston, Jun 19, 2007
  11. That is not my experience, which is that a Creator code will be honored
    even if the filename has an extension that's mapped to a different
    application. If I add a Creator code of "CARO" to a file with a "pdf"
    extension, Finder will use Adobe Reader, the application mapped to the
    "CARO" Creator code, to open it; and Get Info will show Adobe Reader as
    the default "Open with" application for that file. If the file's Creator
    code is empty, those revert to Preview, the application mapped to the
    "pdf" filename extension.
    Neill Massello, Jun 19, 2007
  12. jt august

    David B Funk Guest

    Reading the first article sited there is a paragraph that says:

    The situation for plain files is somewhat less perfect. There are only two
    popular methods for representing concrete types: HFS/HFS+ type/creator
    codes and filename extensions. Mac OS X supports both, but Apple "strongly
    encourages developers to use file extensions as alternative means for
    identifying document types." Apple's reasoning is that the Internet, the new
    "lowest common denominator" of interoperability, does not support
    HFS-style attributes and forks; it deals only in flat files. Where the
    overwhelming majority of "flat file" volume formats (i.e. Windows/FAT,
    Unix/UFS) failed to change Apple's thinking, the pervasive connectivity of the
    multi-million-node Internet has succeeded.

    That sure sounds like an explanation as to why.
    David B Funk, Jun 19, 2007
  13. Except that it's misleading in that it seems to imply that Type and
    Creator codes have something to do with forks versus "flat file" volume
    formats. They don't. Like other "HFS-style attributes", they are part of
    file system metadata, not part of the files themselves.
    Neill Massello, Jun 19, 2007
  14. jt august

    Jon Guest

    Which implies (correct me if I am wrong) that the key thing here is the
    file system and its ability to handle the metadata in question, right?

    That makes it probable to me that the Mac's ability to access FAT, SMB
    or NFS volumes natively, without something specifially Mac-esque being
    installed on them, has to be pretty dependent on suffixes, as thoe FS'es
    aren't built for type/creator coding. But is that correct? I do not
    think I have to suffix a file ".pdf" when I store it on a FAT volume for
    it to be recognised. So where is this stored?
    Jon, Jun 19, 2007
  15. jt august

    Ian Gregory Guest

    It's magic:)

    Actually with Unix based systems it is often magic - the system
    determines the file type by reading the magic number from the
    file itself. You can use file(1) to try to determine file type
    and it uses the magic number if there is one, for example:

    isis$ file glory.mp3
    glory.mp3: MP3 file with ID3 version 2.2.0 tag

    Type "man magic" on the command line for more info.

    Ian Gregory, Jun 19, 2007
  16. jt august

    Jon Guest

    Thanks a lot! Learn something every day. :)
    Jon, Jun 19, 2007
  17. jt august

    David Empson Guest


    XRay's "Type, Creator & Extension" page has a useful visual aid to
    explain the priority scheme: it has fields for all of these things, with
    a big arrow on the left side showing that the highest priority one is on
    top. At the bottom, it shows which application will actually open the

    The priority ordering is:

    1. Specific binding for that file (as set in Get Info).

    2. Creator.

    3. Extension.

    4. Type.

    Thus if you have a file with a bogus creator but a meaningful file type
    then you can override the file type by using a different extension, but
    if the creator is valid then the extension will be ignored.

    This explains the difference between files which ignore the extension
    and always open in the same application when renamed, vs those which
    change application when the extension changes. The former have been
    assigned a creator, while the latter have not.

    It also means that if a document with a creator is copied to another
    system which doesn't contain that application, the creator will be
    ignored (as there is no matching application) and the extension will
    take precedence.
    David Empson, Jun 19, 2007
  18. jt august

    Wes Groleau Guest

    However, he said FAT system, implying Windows. And Windows
    only knows extensions. Try changing readme.pdf to readme.
    Windows will warn you it's a bad idea, and if you do it anyway,
    Windows will try to prove you should have listened.

    Wes Groleau

    Change is inevitable.
    Conservatives should learn that "inevitable" is not a synonym for "bad."
    Liberals need to learn that "inevitable" is not a synonym for "good."
    -- WWG
    Wes Groleau, Jun 20, 2007
  19. jt august

    Jon Guest

    Well, I was really thinking of FAT used with a Mac. But my point was to
    ask whether a FAT volume could retain the necessary information without
    a file suffix. As the two of you together are now saying, if I
    understand it all correctly, magic will take care of it for you on a
    Mac, while if you use that same volume and non-suffixed file on a
    Windows machine, you migh be out of luck.
    Jon, Jun 20, 2007
  20. jt august

    Wes Groleau Guest

    Right. Also on the Mac, if you use Finder to copy a file with a
    resource fork to a non-HFS, it will create a separate resource
    fork file.

    Wes Groleau

    Guidelines for judging others:

    1. Don't attribute to malice that which
    can be adequately explained by stupidity.

    2. Don't attribute to stupidity that which
    can be adequately explained by ignorance.

    3. Don't attribute to ignorance that which
    can be adequately explained by misunderstanding.
    Wes Groleau, Jun 21, 2007
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