Copy files and preserve filestamps, ownership and permissions

Preserve the timestamp, ownership and permissions of a file

When you copy a file on Linux, information about certain attributes is not copied along. For instance, the timestamps, ownership and mode (or file permissions) from the original file will be lost.

Instead, the current timestamp will be used as the timestamp, the current user (and group) will take ownership of the file and the file permissions will be the default permissions. (The same applies to directories by the way.)

If you need to preserve the original mode, timestamps or ownership, you can specify an option to the cp command: --preserve=[ATTR_LIST].

From the man page:

--preserve[=ATTR_LIST]
      preserve the specified attributes (default: mode,ownership,time‐
      stamps), if possible additional attributes: context, links,
      xattr, all

Examples

Default

After we copy original.txt to copy.txt using no preserve options the attributes will look something like this:

$ cp original.txt copy.txt
$ ls -l
-rw-r--r--  1 marek  staff  9 Jan  7 22:30 copy.txt
-rwxrw-r-x  1 _www   staff  9 Jan  7 22:27 original.txt

As you can see, the timestamps, ownership and permissions are different. The owner of the original file was _www, now it is the current user, which is marek. The original timestamp on the original was 22:27, the copy has 22:30. And the (quite remarkable) permissions -rwxrw-r-x are now the default -rw-r--r-- (or 644) permissions.

Timestamps

To retain the original timestamps we only need to specify it like this:

$ cp --preserve=timestamps original.txt copy.txt

Which results in the same timestamps:

-rw-r--r--  1 marek  staff  9 Jan  7 22:27 copy.txt
-rwxrw-r-x  1 _www   staff  9 Jan  7 22:27 original.txt

Ownership

To retain the ownership the command is similar:

$ cp --preserve=ownership original.txt copy.txt

Now, we have:

-rw-r--r--  1 _www   staff   9 Jan  7 22:34 copy.txt
-rwxrw-r-x  1 _www   staff   9 Jan  7 22:27 original.txt

Mode / Permissions

As you probably have guessed, to keep the file permissions:

$ cp --preserve=mode original.txt copy.txt

And now both files have the permissions -rwxrw-r-x:

-rwxrw-r-x  1 marek  staff   9 Jan  7 22:37 copy.txt
-rwxrw-r-x  1 _www   staff   9 Jan  7 22:27 original.txt

All together

Note that we can combine all these commands to preserve the timestamps, ownership and permissions:

$ cp --preserve=timestamps,ownership,mode original.txt copy.txt
-rwxrw-r-x  1 _www   staff   9 Jan  7 22:27 copy.txt
-rwxrw-r-x  1 _www   staff   9 Jan  7 22:27 original.txt

If you followed along closely, you might have noticed in the man page a shorthand option -p to preserve the mode, ownership and timestamps at the same time:

-p     same as --preserve=mode,ownership,timestamps

So, instead of the command above, you could also do this:

$ cp -r original.txt copy.txt