1. This site uses cookies. By continuing to use this site, you are agreeing to our use of cookies. Learn More.

copy /uf and usb key

Discussion in 'Support' started by David Marcus, Feb 23, 2012.

  1. David Marcus

    Joined:
    Jun 4, 2008
    Messages:
    648
    Likes Received:
    1
    I don't understand what is happening with copy /uf. My c: drive is an ntfs hard disk. My f: drive is a FAT USB key. I copy a file from c: to f:, then copy /uf it back. I would expect that it wouldn't be copied back, but it is.

    Code:
    C:\Junk>echo %@filetime[Foo.bar,,s] %@fileage[foo.bar]
    20:37:39 129745030598204083
     
    C:\Junk>copy Foo.bar f:\
    C:\Junk\Foo.bar => F:\Foo.bar
        1 file copied
     
    C:\Junk>echo %@filetime[f:\Foo.bar,,s] %@fileage[f:\foo.bar]
    20:37:40 129745030600000000
     
    C:\Junk>copy /uf f:\Foo.bar .
    F:\Foo.bar => C:\Junk\Foo.bar
        1 file copied
     
    C:\Junk>echo %@filetime[Foo.bar,,s] %@fileage[foo.bar]
    20:37:40 129745030600000000
     
    C:\Junk>ver
    
    TCC  13.03.45   Windows Vista [Version 6.0.6002]
     
  2. Charles Dye

    Charles Dye Super Moderator
    Staff Member

    Joined:
    May 20, 2008
    Messages:
    3,300
    Likes Received:
    39
    Hence the /UF.

    It looks to me like, when Windows copies from NTFS to FAT, the file time gets rounded to the nearest two-second interval, not truncated as I would expect.
     
  3. Steve Pitts

    Joined:
    Jul 7, 2008
    Messages:
    159
    Likes Received:
    0
    I was too quick off the mark Charles, modified my post twice (adding references to the UF and age resolution) and then decided that it was all utter tosh and removed it :)
     
  4. David Marcus

    Joined:
    Jun 4, 2008
    Messages:
    648
    Likes Received:
    1
    Rounding shouldn't matter, since the rounded value should still be less than two seconds from the original value. I can duplicate the problem on Vista and Windows 7 and two different USB keys.
     
  5. David Marcus

    Joined:
    Jun 4, 2008
    Messages:
    648
    Likes Received:
    1
    Is this a bug?
     
  6. rconn

    rconn Administrator
    Staff Member

    Joined:
    May 14, 2008
    Messages:
    9,854
    Likes Received:
    83
    Works here with 13.03.49.
     

Share This Page