Get the type of a file in Cocoa

by

You could use Uniform Type Identifiers. Since UTIs are organised into hierarchies, one possibility is to check whether the preferred UTI for a given file conforms to a top-level UTI, e.g. public.image for images or public.movie for movies. The Core Services framework includes functions that operate on UTIs as well as constants representing known UTIs.

For instance, working on file name extensions:

NSString *file = @"…"; // path to some file
CFStringRef fileExtension = (CFStringRef) [file pathExtension];
CFStringRef fileUTI = UTTypeCreatePreferredIdentifierForTag(kUTTagClassFilenameExtension, fileExtension, NULL);

if (UTTypeConformsTo(fileUTI, kUTTypeImage)) NSLog(@"It's an image");
else if (UTTypeConformsTo(fileUTI, kUTTypeMovie)) NSLog(@"It's a movie");
else if (UTTypeConformsTo(fileUTI, kUTTypeText)) NSLog(@"It's text");

CFRelease(fileUTI);

If you have a MIME type instead of a file name extension, you can use kUTTagClassMIMEType instead of kUTTagClassFilenameExtension.

For a list of known UTIs, see this document.

More Related Contents:

  1. Difference between objectForKey and valueForKey?
  2. Best way to define private methods for a class in Objective-C
  3. Picking a Random Object in an NSArray
  4. How to sort NSMutableArray using sortedArrayUsingDescriptors?
  5. Objective-C Introspection/Reflection
  6. NSString tokenize in Objective-C
  7. How can I add properties to an object at runtime?
  8. What is meant by .delegate=self?
  9. Difference between self.var and simply var
  10. Save NSDictionary to plist
  11. How to compare two dates in Objective-C
  12. If “a == b” is false when comparing two NSString objects
  13. Are classes objects in Objective-C?
  14. How to get the reference count of an NSObject?
  15. How to escape double quotes in string?
  16. Check that an email address is valid on iOS [duplicate]
  17. NSString is integer?
  18. Class Foo is implemented in both MyApp and MyAppTestCase. One of the two will be used. Which one is undefined
  19. NSTimeZone: what is the difference between localTimeZone and systemTimeZone?
  20. What is the simplest implementation of Markdown for a Cocoa application?
  21. Observe a File or Folder in Objective-C
  22. How to wake from sleep programmatically if lid closed?
  23. Creating a ZIP archive from a Cocoa application
  24. How to create transparent notification window?
  25. Properties and Instance Variables in Objective-C
  26. Chaining Core Animation animations
  27. NSString – Convert to pure alphabet only (i.e. remove accents+punctuation)
  28. Getting array elements with valueForKeyPath
  29. Looping using NSRange
  30. NSNumber of seconds to Hours, minutes, seconds

Leave a Comment