linux、unix、OSX生成uuid

uuidgen

uuid_generate(uuid_t uu),

// Create universally unique identifier (object)  
CFUUIDRef uuidObject = CFUUIDCreate(kCFAllocatorDefault);  

// Get the string representation of CFUUID object.  
NSString *uuidStr = (NSString *)CFUUIDCreateString(kCFAllocatorDefault, uuidObject);  
CFRelease(uuidObject);