So many different applications could open TEXT files, but very few could open WDBN files. Application writers could tell their applications which types of files it could open. For example, plain text files were type 'TEXT' and MS Word documents were 'WDBN'. Similarly, every file could have a file type code assigned to it.

The OS maintained a database of which creator codes matched which applications, so that when the user double-clicked a file, the OS would look up the creator code in its database and launch the proper application. A unique creator signature was assigned to every application and any file could store a creator code in its resource fork. The Mac Classic operating system used four-character codes to keep track of what application should be used to open specific files and what type of files applications could open. (For use with the fileType and stackFileType properties)īy Devin Asay Creator Signatures and File Types Office of Digital Humanities Back BYU LiveCode Lessons Gateway Mac Creator Signature and File Types in Revolution/LiveCode

Set default program for extension mac