UNIX for Advanced & Expert Users

How do I make tar set the correct atime on the extracted version? The option --atime-preserve works just on the original, not on the extracted file.
The extracted files always have current time as atime, which is bad.

use the -p option when you extract it.

That was quick. Thanks!



This does not seem to work though. See below an example where 2 files (with different atimes) are archived and extracted somewhere else. The last line of output shows that the atime was not preserved.

$ ls -lt origin/b*
-rw-r--r-- 1 dsilt2 dsilt2 4 2008-12-15 03:52 origin/bla2
-rw-r--r-- 1 dsilt2 dsilt2 4 2007-07-07 22:22 origin/bla1
$ ls -ltu origin/b*
-rw-r--r-- 1 dsilt2 dsilt2 4 2008-12-15 03:52 origin/bla2
-rw-r--r-- 1 dsilt2 dsilt2 4 2007-07-07 22:22 origin/bla1
$ cd origin/
$ tar --atime-preserve -cvpf archive.tar *
bla1
bla2
$ mv archive.tar ../destination/
$ cd ../destination/
$ tar xvpf archive.tar
bla1
bla2
$ ls -lt b*
-rw-r--r-- 1 dsilt2 dsilt2 4 2008-12-15 03:52 bla2
-rw-r--r-- 1 dsilt2 dsilt2 4 2007-07-07 22:22 bla1
$ ls -ltu b*
-rw-r--r-- 1 dsilt2 dsilt2 4 2008-12-15 04:01 bla1
-rw-r--r-- 1 dsilt2 dsilt2 4 2008-12-15 04:01 bla2

can you add --atime-preserve when you do the extract?

Sure. Same result. Files are as in previous shell log.

$ rm destination/bla*
$ cd destination/
$ tar --atime-preserve -xvpf archive.tar
bla1
bla2
$ ls -lt b*
-rw-r--r-- 1 dsilt2 dsilt2 4 2008-12-15 03:52 bla2
-rw-r--r-- 1 dsilt2 dsilt2 4 2007-07-07 22:22 bla1
$ ls -ltu b*
-rw-r--r-- 1 dsilt2 dsilt2 4 2008-12-15 04:22 bla1
-rw-r--r-- 1 dsilt2 dsilt2 4 2008-12-15 04:22 bla2

I should add that I don't necessarily have to work with tar, *any* tool that can do it is fine by me, say cpio, scp, and so on. It's just that tar, according to its documentation, at least *seems* able to preserve time and atime (and permissions of course). If someone knows of any other tool that can move files between computers and preserves those 3 things, that's fine by me too.

Hi.

My reading of this:

Code:

`--atime-preserve'
     Tells `tar' to preserve the access time field in a file's inode
     when reading it.

-- excerpt from info tar

leads me to believe that this on the source side, not on the target side. In other words, tar obtains the inode times, reads the file into the accumulation of the output file, then resets the inode times to the original.

Some filesystems are set not to even record the access times, since it is often of limited value and causes disk activity.

If my supposition is correct, then one could use touch to reset the access times on the target -- tedious, but doable.

Perhaps someone will stop by with a definitive answer ... cheers, drl