You have to handle MacBinary to allow uploads from most Macintosh browsers. Many other components claim to be able to support MacBinary but their support consists of stripping out what they consider relevant and then throwing away everything else.

So how come ABCUpload is 120% MacBinary compatible? Well ABCUpload is the only product to use all the information available. If you upload a Macintosh file to a server running Services for Macintosh (SFM) your Mac file will appear just like it left your client - icons, previews and file name completely intact. ABCUpload is the only product to do this so we gave it an extra 10%. Additionally Internet Explorer sometimes incorrectly codes the MacBinary so ABCUpload has to read the corrupted format. As this happens about 10% of the time we gave ABCUpload another 10%. ABCUpload - 120% MacBinary compatible.

In detail...

Macintosh files are different from Windows or UNIX files in three main ways:

  • Every file consists of two separate streams or forks. The data fork holds the basic file information that you would find in a Windows file. The resource fork contains a database of other associated information such as picture previews, notes and icons. So a BMP image might contain the BMP in the data fork and a icon, preview and copyright note in the resource fork.
  • Macintosh files do not contain a file type extension. Instead they have a hidden type and creator code.
  • Macintosh file names can contain almost any character except for the colon character. This means that it is common to have Macintosh files containing slashes, question marks and asterisks.

When Internet Explorer uploads a file from a Macintosh it chooses to put all this information together into one big stream encoded as MacBinary. ASP.NET doesn't understand this format at all and MacBinary encoded uploads will appear to have been corrupted if you use standard .NET functionality. Some ASP upload components claim to be MacBinary compatible - they just rip out the data fork. However if you do this you loose all sense of what type of file was uploaded and some types of files such as EPS and QuickTime movies can be completely destroyed by this process.

At a basic level we use the creator and type properties to infer the file type. Then we take this one step further. Microsoft has given us the ability to handle this kind of file completely correctly. So if you use ABCUpload to save a MacBinary file to an NTFS formatted disk you can maintain complete integrity of data fork, resource fork, file type and creator. If you look at such a file from Windows it will look like a standard file (e.g. JPEG, DOC etc.) but if you serve this file to Macintosh users using Services for Macintosh (SFM) they will see the original file completely intact.