A creator code is a mechanism introduced in the classic Mac OS to link a data file to the

application program Application may refer to: Mathematics and computing * Application software, computer software designed to help the user to perform specific tasks ** Application layer, an abstraction layer that specifies protocols and interface methods used in a c ...

which created it. The similar type code held the file type, like "TEXT". Together, the type and creator indicated what application should be used to open a file, similar to (but richer than) the

file extension A filename extension, file name extension or file extension is a suffix to the name of a computer file (e.g., .txt, .docx, .md). The extension indicates a characteristic of the file contents or its intended use. A filename extension is typically d ...

s in other operating systems. Creator codes are four-byte OSTypes. They allow applications to launch and open a file whenever any of their associated files is double-clicked. Creator codes could be any four-byte value, but were usually chosen so that their

ASCII ASCII ( ), abbreviated from American Standard Code for Information Interchange, is a character encoding standard for electronic communication. ASCII codes represent text in computers, telecommunications equipment, and other devices. Because ...

representation formed a word or acronym. For example, the creator code of the

HyperCard HyperCard is a software application and development kit for Apple Macintosh and Apple IIGS computers. It is among the first successful hypermedia systems predating the World Wide Web. HyperCard combines a flat-file database with a graphical, f ...

application and its associated "stacks" is represented in

as , from the application's original name of WildCard. Occasionally they represented

inside joke An in-joke, also known as an inside joke or a private joke, is a joke whose humour is understandable only to members of an ingroup; that is, people who are ''in'' a particular social group, occupation, or other community of shared interest. It i ...

s. For instance, the '' Marathon'' computer game had a creator code of (the approximate length, in miles, of a marathon) and '' Marathon 2: Durandal'' had a creator code of . The binding are stored inside the

resource fork The resource fork is a fork or section of a file on Apple's classic Mac OS operating system, which was also carried over to the modern macOS for compatibility, used to store structured data along with the unstructured data stored within the data f ...

of the application as BNDL and fref resources. These resources maintained the creator code as well as the association with each type code and

icon An icon () is a religious work of art, most commonly a painting, in the cultures of the Eastern Orthodox, Oriental Orthodox, and Catholic churches. They are not simply artworks; "an icon is a sacred image used in religious devotion". The most ...

. The OS collected this data from the files when they were copied between mediums, thereby building up the list of associations and icons as software was installed onto the machine. Periodically this "desktop database" would become corrupted, and had to be fixed by "rebuilding the desktop database." The key difference between extensions and Apple's system is that file type and file ownership bindings are kept distinct. This allows files to be written of the same type - TEXT say - by different applications. Although any application can open anyone else's TEXT file, by default, opening the file will open the original application that created it. With the extensions approach, this distinction is lost - all files with a .txt extension will be mapped to a single text editing application of the user's choosing. A more obvious advantage of this approach is allowing for double click launching of specialized editors for more complex but common file types, like .csv or .html. This can also represent a disadvantage as in the illustration above, where double clicking the four mp3 files would launch and play the files in four different music applications instead of queuing them in the user's preferred player application. macOS retains creator codes, but supports extensions as well. However, beginning with

Mac OS X Snow Leopard Mac OS X Snow Leopard (version 10.6) is the seventh major release of macOS, Apple's desktop and server operating system for Macintosh computers. Snow Leopard was publicly unveiled on June 8, 2009 at Apple’s Worldwide Developers Conference. ...

, creator codes are ignored by the operating system. Creator codes have been internally superseded by Apple's Uniform Type Identifier scheme, which manages application and file type identification as well as type codes, creator codes and file extensions. To avoid conflicts, Apple maintained a database of creator codes in use. Developers could fill out an online form to register their codes. Apple reserves codes containing all lower-case ASCII characters for its own use. Creator codes are not readily accessible for users to manipulate, although they can be viewed and changed with certain software, most notably the macOS command line tools ''GetFileInfo'' and ''SetFile'' which are installed as part of the developer tools into ''/Developer/Tools''.

References

External links

How application binding policy changed in Snow Leopard
* {{Mac OS Macintosh operating systems Metadata

See also

References

External links