[all2ofme]

I've copied a few files from my Powerbook (10.3.6) across to a linux box I have (running Suse) and while most of the files are the same size when I check them now, some of them are slightly different. Only by a few bytes, but different.

I've tried copying those files again, and it works ok with individual files. I've also tried to copy the files back again to see if they change going the other way, but it would seem now. File sizes remain as they were.

Here's an example (same file)
Pbook: 6,500,470
Same file copied to linux: 6,500,470

Linux (copied along with a few others last week): 6,500,356
Same copied to Pbook: 6,500,356

I hope I'm making myself clear. Does anyone know why this might be the case?

[jasong]

It's been a long day, but your numbers look the same to me . . .

Pbook: 6,500,470
Same file copied to linux: 6,500,470

Linux (copied along with a few others last week): 6,500,356
Same copied to Pbook: 6,500,356

-- Jason

[all2ofme]

Long day for me too - I don't think I'm making myself as clear as I need to

The two files I've listed are one and the same (copied from the Powerbook to the linux box about a week ago). The difference of 114 bytes shown is what's bothering me. The reason I showed the info you quoted was to show that it doesn't always happen, as the same file copied back and forth between the machines now appears not to change anything.

However, somewhere along the line there's something awry. Would love to know what, as I want to backup all these files.

[larkost]

Are they text files? can you diff them?

[wataru]

Could it be a filesystem thing?

[Laurence]

If the files contain resource forks then those will be stripped when copying to Linux, Windows, UFS, etc. Basically anything other than HFS or HFS+

For some files (w/o resource forks) there would be no size difference, but other files could be off by any amount up to the size of the file. (in the case of a file with no data fork)

[Xeo]

use md5 on them to see if the hashes are the same

[all2ofme]

Thanks for the replies, everyone.

Tried an MD5 hash (which was different - should have been, I guess, different file sizes and all).

Tried moving it around between other FS to see if that was anything to do with it, no joy.

Ended up bringing it up in TextEdit and finding that this was near the start of the bigger file:

Edit: See screenshot instead http://81.6.236.94/~ben/difference.gif

[Xeo]

Originally posted by all2ofme:
Thanks for the replies, everyone.

Tried an MD5 hash (which was different - should have been, I guess, different file sizes and all).

Tried moving it around between other FS to see if that was anything to do with it, no joy.

Ended up bringing it up in TextEdit and finding that this was near the start of the bigger file:

EP

Well that's only 2 bytes difference. So there's more different than that.

[all2ofme]

You're right, of course. For some reason not all of what I pasted in has displayed. Here's a screenshot showing both in TextEdit.

http://81.6.236.94/~ben/difference.gif

[tooki]

The differences there are in the ID3 tags. The filesystem will never alter the contents of a file: these differences weren't caused by the move to/from Linux. These differences are in the ID3 tags (where things like song title, genre, etc are stored). Presumably the Linux MP3 player decided to add more tags.

tooki

[all2ofme]

Interesting. I thought that ID3 tags were still stored at the end of files, but right you are. Actually it was iTunes adding data, so my best guess so far is that it was adding the more unusual tag info such as play count and ratings.

Originally posted by tooki:
The differences there are in the ID3 tags. The filesystem will never alter the contents of a file: these differences weren't caused by the move to/from Linux. These differences are in the ID3 tags (where things like song title, genre, etc are stored). Presumably the Linux MP3 player decided to add more tags.

tooki

[The Godfather]

Maybe if you make the file a read-only the file size will not change.