[SOLVED] Cloning files permissions and ownership

Teufel · 02-12-2018, 09:13 AM

I have to clone files permissions and ownership for entire /usr directory. I can't just copy files because the source and the destination files built with different cflags and different options. I just need to clone permissions on built files.

There is --reference=RFILE option for chown/chmod commands, but I don't know how to use these command recursively with that option.

I doubt that

Code:

chown --reference=/usr /mount_point/usr -R

will work
though

Code:

chown owner:owner /mount_point/usr -R

works

Any thoughts or ideas?

MensaWater · 02-12-2018, 09:44 AM

You can do a loop for all the files:

Code:

cd /usr 
for file in $(find .)
do chown --reference=$file /mount_point/usr/$file
done

Teufel · 02-12-2018, 10:39 AM

it gives output like this:

Code:

chown: cannot access '/media/usr/./share/apps/amarok/images/smallstar.png': No such file or directory

so I modified your script a bit:

Code:

for file in $(find  /usr)
do chown --reference=$file /media$file
done

now it finds filenames with absolute path instead of relative "./"

Thanks.

MensaWater · 02-12-2018, 12:23 PM

Glad you got it solved.

I notice you changed name of the target path between your initial post and your final one.

Also you may have missed that I said you should cd to the source directory, /usr, before running the find. The syntax I wrote worked properly when I did a test here. "find ." means "find from this location so if you're sitting in /usr it would do the find there but wouldn't include the "/usr" in the output. Either way should work.

MadeInGermany · 02-12-2018, 01:14 PM

Use chown -h so it also changes ownership of symlinks. (Otherwise follows the symlinks, that can be dangerous in some scenarios.)
Also, quote variables in command arguments.

Code:

for file in $(cd /usr && find .)
do chown -h --reference="$file" /media/usr/"$file"
done

Teufel · 02-12-2018, 02:50 PM

@MensaWater
"find ." returns relative filename, it starts with "./" symbols.
In fact, related to the current directory, it gives right filename, but when "./" prepended with the destination directory (like /media/usr) it gives wrong file name: "/media/usr/./some_sub_dir" with the dot in the middle.
I posted above the sample of erroneous filename
So, to fix this error we need to get absolute file name like "/usr/some_sub_dir" in $file variable which being concatenated with "/media" gives correct path: "/media/usr/some_sub_dir" without any dot in the middle
And "find /usr" returns absolute filename.
This case "cd /usr" command is unnecessary.

MadeInGermany · 02-12-2018, 03:57 PM

Effectively an extra ./ does not change anything.
For example

Code:

ls /usr/bin
ls /usr/./bin
ls /usr/././bin

are effectively identical.

Teufel · 02-13-2018, 02:58 AM

Not sure why it occurs but with extra dot I getting a zillion errors "No such file or directory"