MagicKit.framework is an easy-to-use wrapper around the libmagic file identification library. It provides a high-level Objective-C interface and deals in Foundation types (NSString, NSData, et al).
MagicKit.framework is available for both OS X (as a framework) or iOS as a static library with header files. MagicKit.framework consists of a master class, GEMagicKit, and an intermediary class, GEMagicResult. The GEMagicKit master class has six class methods, listed below in descending order of convenience.
+ (GEMagicResult *)magicForFileAtPath:(NSString *)path;
+ (GEMagicResult *)magicForFileAtURL:(NSURL *)aURL;
+ (GEMagicResult *)magicForData:(NSData *)data;
+ (GEMagicResult *)magicForFileAtPath:(NSString *)path decompress:(BOOL)decompress;
+ (GEMagicResult *)magicForFileAtURL:(NSURL *)aURL decompress:(BOOL)decompress;
+ (GEMagicResult *)magicForData:(NSData *)data decompress:(BOOL)decompress;
These methods all return the GEMagicResult intermediary class. The GEMagicResult class has four properties. These are mimeType, description, uniformType and uniformTypeHierarchy. the first three properties are NSString objects, the final returns an NSArray object.
Example MIME types include:
application/xml; charset=us-asciivideo/x-msvideo; charset=binary
Or a textual description, respectively:
XML document textRIFF (little-endian) data, AVI, 624 x 352, 23.98 fps, video: XviD, audio: MPEG-1 Layer 3 (stereo, 48000 Hz))
Finally, uniformType and uniformTypeHierarchy return Uniform Type Identifiers for the relevant file/data. The type hierarchy is an array of types that the given file conforms to.
GEMagicKit can also decompress compressed files and hence attempt to determine the contents within.
MagicKit.framework is MIT-licensed. libmagic is BSD-licensed.