Thanks Esther, As always you answered all of my questions.
Robert Carter ----- Original Message ----- From: Esther <[email protected]> To: [email protected] Date: Monday, Jul 20, 2009 11:57:54 Subject: Apple Double Format "Dot Underscore" files [was Re: NFB Newsline files and the mac] > > > > HI Robert, Scott, and Others, > > >ar Robert Carter wrote: > >>> > >>> I am curious if anybody can explain this. I have been going to the > >>> Nfb Newsline Online site and having my Newspaper emailed to me. The > >>> Newspaper consists of 4 DAISY files. If I copy and paste these files > >>> onto an SAID card using my iMac, I end up with 8 files in the folder > >>> which seem to be two duplicates of each of the original 4 files. > >>> Does anybody understand why this happens? I am just curious about > >>> it. > >ar > > > and Scott asked: > > > > Not got a sollution, more of a question. I think I've seen the same > > behaviour you described. Next time it happens, can you check the file > > sizes of both copies you get? For me, it was always that one was the > > full size of the file, the other would be tiny like 32kb or something. > > I think what you're seeing is something called "Apple Double format", > and it occurs when you do a copy and paste to a FAT32 formatted device > like your SAID card or a USB memory stick (among other > circumstances). The set of files which Scott mentions as being 32kb > in size will have names that are preceded by a period and then an > underline character followed by the regular file name, and are > referred to as "dot underscore" files. (You'll have to read the > filenames by character to hear the prefix characters with VoiceOver.) > Basically, Apple's file system keeps track of two kinds of information > -- a data fork and a resource fork. You know that when you open files > on the Mac you can specify which application is used on a per file > basis. Mp3 files can be played with VLC, QuickTime, iTunes, Amadeus > Pro, etc. That kind of data (and other information about the file) is > stored in the resource fork. It doesn't get used when you transfer > files from a Mac to Windows, but it does have information if you were > to transfer the files (say, on a USB memory key) to another Mac. This > is described in Apple's Knowledge Base: > > http://support.apple.com/kb/TA20578 > (Apple Double Format Creates File Name With the Prefix 'dis_') > > You can safely delete the small dot underscore files. Under Leopard, > there's a "dot_clean" command available from terminal that will do > this. Here's the description of the dot_clean man page: > http://developer.apple.com/documentation/Darwin/Reference/ManPages/man1/dot_clean.1.html > With your SAID card mounted, launch a Terminal session (e.g. from > Finder use Command-Shift-U then press "t e" to go to "Terminal" and > Command-Down Arrow to open). > Type a command like: > dot_clean /Volumes/SD/ > where you substitute the actual path to your mounted SAID card as the > argument for dot_clean (and press enter after you type the command). > You can find the device in your Finder sidebar and use the Get Info > window (Command-I) to find the path to mounted device. Remember to > close the Get Info window with Command-W when you're done. > There are commercial solutions GUI-based solutions like BlueHarvest, > too. > http://zeroonetwenty.com/blueharvest/ > Incidentally, this is also an issue for people trying to move files > between the Mac and linux via tar savesets. You can disable the > extended attributes from the bash shell in terminal with: > export COPY_EXTENDED_ATTRIBUTES_DISABLE=TRUE > to avoid including created dot underscore files, or you can just > transfer the files via FTP or SFTP. > > HTH > Cheers, > Esther > > > > > > > > > --~--~---------~--~----~------------~-------~--~----~ > You received this message because you are subscribed to the Google Groups > "MacVisionaries" group. > To post to this group, send email to [email protected] > To unsubscribe from this group, send email to > [email protected] > For more options, visit this group at > http://groups.google.com/group/macvisionaries?hl=en > com~----------~----~----~----~------~----~------~--~--- --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "MacVisionaries" group. To post to this group, send email to [email protected] To unsubscribe from this group, send email to [email protected] For more options, visit this group at http://groups.google.com/group/macvisionaries?hl=en -~----------~----~----~----~------~----~------~--~---
