copy file, keep permissions and owner

Question

The docs of shutil tells me:

Even the higher-level file copying functions (shutil.copy(), shutil.copy2()) can’t copy all file metadata. On POSIX platforms, this means that file owner and group are lost as well as ACLs

How can I keep the file owner and group if I need to copy a file in python?

The process runs on linux as root.

Update: We don't use ACLs. We only need to keep the stuff which is preserved with tools like tar and rsync.

score 23 · Accepted Answer · edited May 23 '17 at 12:18

23

You perhaps could use os.stat to get the guid and uid like in this answer and then reset the uid and guid after coping using os.chown.

edited May 23 '17 at 12:18

Community

1
1

answered Nov 12 '13 at 16:43

Thom Wiggers

6,938
1
39
65

1

You should read the shutil documentation. `copy2` get everything but owner/group. – lunixbochs Nov 12 '13 at 16:44
1

You can get `uid` and `guid` using `os.stat` though. – Thom Wiggers Nov 12 '13 at 16:45
2

@lunixbochs: what is wrong with reading uid, gid of the source file using `os.stat` then setting them on the destination file using `os.chown(path, uid, gid)`? – jfs Nov 12 '13 at 16:46
3

Works for me. I just saw chmod, not chown (was that in your edit?). You should note the potential requirement for root privileges to arbitrarily set user/group to someone other than yourself. – lunixbochs Nov 12 '13 at 16:47
1

@lunixbochs: the question clear says: "The process runs on linux as *root*." – jfs Nov 12 '13 at 16:53

Mayra Delgado · Answer 2 · 2021-08-30T13:27:08.673

20

I did it this way:

import os
import stat
import shutil

def copyComplete(source, target):
    # copy content, stat-info (mode too), timestamps...
    shutil.copy2(source, target)
    # copy owner and group
    st = os.stat(source)
    os.chown(target, st.st_uid, st.st_gid)

edited Aug 30 '21 at 13:27

answered May 03 '17 at 13:12

Mayra Delgado

531
4
17

This is a great solution. Thanks. – Phlox Midas Oct 06 '17 at 08:41
Good work. I like that this is portable. Even though the OP specifically noted linux as the OS, I appreciate a portable answer. – bballdave025 Sep 11 '18 at 19:34
1

why not just `os.chown(target, st.st_uid, st.st_gid)` – yutseho Aug 25 '21 at 02:26

score 9 · Answer 3 · answered Nov 12 '13 at 17:51

9

You can use the subprocess module:

from subprocess import Popen

p = Popen(['cp','-p','--preserve',src,dest])
p.wait()

answered Nov 12 '13 at 17:51

user545424

15,713
11
56
70

1

Yes,this works. But I search a solution without creating subprocesses. – guettli Nov 12 '13 at 19:37
1

This gets very slow, if you copy a lot of files. – guettli Feb 07 '14 at 10:17

score 2 · Answer 4 · edited May 23 '17 at 12:02

2

See Keeping fileowner and permissions after copying file in C on how cp itself does this, then just replicate its logic. Python has all the system calls mentioned in its os module.

edited May 23 '17 at 12:02

Community

1
1

answered Nov 19 '13 at 10:50

ivan_pozdeev

33,874
19
107
152

score 1 · Answer 5 · edited Nov 19 '13 at 07:53

I suggest you use the OS and subprocess modules. This will only work in Unix, but it should work well. Use the os.fchown to change file ownership, and subprocess.Popen() to pipe ls -l into a variable to read ownership. For one file, the permissions reader would look like this:

import os
import subprocess

def readfile(filepath):
    process = subprocess.Popen(["ls","-l"],stdout=subprocess.PIPE)
    output = process.communicate()[0]
    output = output.split()
    return (output[0],output[1])  #insert into this tuple the indexing for the words you want from ls -l

and for the uid setter (just a wrapper for os function):

def setuid(filepath,uid,gid):
    os.chown(filepath,uid,gid)

True enough. Especially since os has a function to list the contents of a directory programmatically. Probably better to use that. — trevorKirkby, Jun 18 '16 at 06:22

score 1 · Answer 6 · answered Sep 05 '18 at 09:05

1

as @Thom Wiggers 's answer

os.stat get uid,gid
os.chmod set uid,gid

demo code:

import os
st = os.stat(src_path)
os.chown(dst_path, st.st_uid, st.st_gid)

check except:

import os
def copy_owner_group(src, dst):
    try:
        st = os.stat(src)
    except Exception as e:
        print 'stat except:', e
    else:
        try:
            os.chown(dst, st.st_uid, st.st_gid)
        except Exception as e:
            print 'chmod except:', e

answered Sep 05 '18 at 09:05

yurenchen

1,897
19
17

4

I just ask myself "Why do I need to do coding for this? Why is there no lib which handles this?" – guettli Sep 05 '18 at 09:34

copy file, keep permissions and owner

6 Answers6

Linked