On Jun 12, 2010, at 7:18 AM, Ben wrote: > Hi list > > Given an NSData object, with no context as to what it might be, is it > possible to find if it contains a document of recognised file type? > > I know this is possible for image files, by using the imageIO framework and > doing the following: > > CGImageSourceRef imageSource = > CGImageSourceCreateWithData(myNSDataObjectGoesHere, NULL); > NSString *uti = (NSString *)CGImageSourceGetType(imageSource); > NSString *extension = [[NSWorkspace sharedWorkspace] > preferredFilenameExtensionForType:uti]; > CFRelease(imageSource); > // Standard typed-in-mail-disclaimer here > > > I suppose I could take the long route of writing the data to disk, then using > the NSWorkspace method -typeOfFile:error:, but that seems a bit heavy-handed. > > Can anyone suggest a better way of doing this? I've been unable to find > anything in the archives or Google, but perhaps I'm using the wrong search > terms. > > - Ben
If it’s just for a few types you support, it’s not too hard to check the first few bytes to see if they match the magic number of any format you support. For example, JPEG files start with 0xff, 0xd8. The magic numbers for most types can be found online (Wikipedia is actually a pretty good resource for this a lot of the time), or you can sift through the files in /usr/share/file/magic. Charles_______________________________________________ Cocoa-dev mailing list (Cocoa-dev@lists.apple.com) Please do not post admin requests or moderator comments to the list. Contact the moderators at cocoa-dev-admins(at)lists.apple.com Help/Unsubscribe/Update your Subscription: http://lists.apple.com/mailman/options/cocoa-dev/archive%40mail-archive.com This email sent to arch...@mail-archive.com
