3 Replies Latest reply: Jan 30, 2013 12:30 AM by RodneyW
Danimal2013 Level 1 Level 1 (0 points)

I am a new Mac user (why did it take me so long?!).  I am bringing data together from two different PCs with similar folder structures and have been struggling to understand Mountain Lion's folder merge functionality.  Research on the web has not revealed much other than this functionality is new and I cannot find any detailed documentation that would help.


My question is this: when I merge two folders with the same name, both with multiple sub-folders, many of which also have the same names in the same places in the hierarchy and where there will be a mixture of new files, duplicates and different versions of the same files, what is the behavior of the merge function (command and drag)?  Specifically, how are subfolders treated?  Are they merged as Windows merges them, with options to "keep both" or overwrite with the newer version in the case of duplicates and combination of distinct files right down the hierarchy?


I am nervous because I read somewhere that Mountain Lion merges the top level folder is this way, but replaces all subfolders per previous Mac OS behavior. 


Thanks in advance.

iMac, OS X Mountain Lion (10.8.2)
  • 1. Re: Folder merge behavior
    RodneyW Level 4 Level 4 (3,030 points)

    The Finders functionality for folder merging is very limited.


    It wil work if the folder being copied has no sub-folders.


    If you wish to copy an entire folder structure from one place to another, you can use a Terminal command:


    ditto -V sourcefolder destinationfolder


    This will copy sourcefolder into destinationfolder, retaining the unique files of destinationfolder, but over-writing any files that have the same name as the one in sourcefolder.


    Alternatively, you can use the a different command to prompt you as to whether or not you want to over-wrote files that have the same name:


    cp -R -v -i sourcefolder/. destinationfolder

  • 2. Re: Folder merge behavior
    Danimal2013 Level 1 Level 1 (0 points)



    Thank you.  This helped clarify.  I am not comfortable with using language and / tools I don't understand, especially where the cost of getting it wrong is so high.  Do you(or anyone)  know of any tools that mimic Windows' functionality?  I have come across utlities like DeltaWalker and Araxis and Big Mean Folder Machine but these seem rather OTT, and MoveAddict which seems to have limited funcionality and takes FOREVER to merge firing off the mac "ping" for every action it completes.  Ifnot, will i be better to merge my folders using Windows and then copy the output back to mac?


    Thank you again, I appreciate you taking the time to reply.



  • 3. Re: Folder merge behavior
    RodneyW Level 4 Level 4 (3,030 points)

    No problems - anytime!


    The fact is that a GUI tool is not really any safer than the command line - it is just a different mechanism for executing a program.


    If you feel more comfortable doing the merge in Windows, then it is probably a good idea to go with your gut!  File operations such as this are one area where the OS X GUI is arguably behind Windows.


    On the other hand, I actually feel more comfortable using the command line these days - it gives fantastic control and flexibility.  Then again, I also like skydiving as a sport.....