Hi Gary, Thank you for your low level fine solution. Anyway, I'm afraid that Apple changes the alias-rule and this method will not work longer. Do you have a solution at a upper level? Or may I be 100% sure that Apple will never change this rule?
Regards -- Leonardo > Da: "Gary L. Wade" <garyw...@desisoftsystems.com> > Data: Fri, 27 Nov 2015 16:48:43 -0800 > A: Leonardo <mac.iphone....@gmail.com> > Cc: <cocoa-dev@lists.apple.com> > Oggetto: Re: FSIsAliasFile deprecated - typeOfFile is slow > > Although I have experience with your performance hit, one solution I would > probably try when it becomes important again for me would be to do this: > > 1. Using the BSD layer of APIs, see if the file (alias files are regular files > from a statfs call, even folder aliases) has an extended attribute named > "com.apple.FinderInfo". If it does not, it is not an alias file. > 2. If the extended attribute does exist and is of length 32 bytes (or more > although doubtful this would ever change), you might have an alias file. If > less, just say no assuming corruption. > 3. Get the bytes of the extended attribute and examine the byte at index 8 > (bytes[8]) to see if its high bit is set (bytes[8] | 0x80). If so, you have an > alias; if not, you don't. > 4. Add this logic in an appropriate category method (to keep this Cocoa). > > For reference, look up ATTR_CMN_FNDRINFO, xattr, Finder.h. Note this extended > attribute has its integers in big-endian format. You might also look at the > fileType parameter of the CoreServices FileInfo that maps the first 16 bytes, > but that requires more checking. > -- > Gary L. Wade (Sent from my iPhone) > http://www.garywade.com/ > >> On Nov 27, 2015, at 2:00 PM, Leonardo <mac.iphone....@gmail.com> wrote: >> >> Hi, >> I actually detect whether a file is an alias this way: >> I use a NSString category where self is the filePath. >> >> - (BOOL)IsAliasOld >> { >> FSRef sourceRef; >> >> OSErr err = [self GetFSRef:&sourceRef]; >> if(err) return NO; >> >> Boolean isFSDirectory, aliasFileFlag; >> >> err = FSIsAliasFile(&sourceRef, &aliasFileFlag, &isFSDirectory); >> if(err) return NO; >> else return aliasFileFlag; >> } >> >> - (OSErr)GetFSRef:(FSRef*)sourceRef >> { >> const char *cSrcPath = [[NSFileManager defaultManager] >> fileSystemRepresentationWithPath:self]; >> if(cSrcPath == 0 || *cSrcPath == _NUL) return -1; >> >> OSErr err = FSPathMakeRefWithOptions((UInt8*)cSrcPath, >> kFSPathMakeRefDoNotFollowLeafSymlink, sourceRef, NULL); >> return err; >> } >> >> >> Since FSIsAliasFile is deprecated (I compile for 10.9) I would now use >> >> - (BOOL)IsAliasNew >> { >> NSString *type = [[NSWorkspace sharedWorkspace] typeOfFile:self >> error:nil]; >> return [type isEqualToString:@"com.apple.alias-file"]; >> } >> >> The problem is that the IsAliasNew method is 3.7 times slower than the >> IsAliasOld method. Do you know a way to accomplish that with a faster >> method? >> _______________________________________________ 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: https://lists.apple.com/mailman/options/cocoa-dev/archive%40mail-archive.com This email sent to arch...@mail-archive.com
