How to transfer files over 4GB from Mac to Windows via USB media

Background to writing this article

There is a problem with trying to pass large files from Mac to Windows via USB media.

That is, the format that each other can read and write is FAT32, and FAT32 does not support sizes larger than 4GB, so you have to split the file into 4GB or less in some way.

It is a memo about the method I did.

Commands and usage

Command to split

The command to split is "split".

In the following command, “big” is split by setting “Capacity to split” to “3000m (≒ 3GB)” with the “-b” option.

The resulting file will be split as ".aa", ".ab", ".ac" ... extension.

 $ split -b 3000m bigfiledat. 

Command to join

The command to be combined is "cat" (Mac) or "copy" (Windows).

The following command combines the files split by the above split command into "".

If cat, specify as follows:

 $ cat bigfiledat.* > 

If it is copy, specify as follows.

 $ copy /b bigfiledat.* 

Both will automatically recognize the extension of ".aa", ".ab", ".ac" ... and combine them.


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