Change permissions upon uploading with scp

Question

I am uploading files to my shell account using scp. As I need different permissions on the server than on my computer, I'd like to have a way to easily change the permissions upon upload without needing to ssh to the account and change them manually.

Answer 1

If you're copying from a windows machine, you can use WinSCP to copy, and it has an option to set the permissions on the copied files after the upload.

If not, I think your only choice is to execute a chmod on the server after the upload, which you could do remotely with an ssh command:

scp /path/to/file server:/server/path/to/file
ssh server chmod 644 /server/path/to/file

Answer 2

You could do it using tar, ssh, & umask like this:

on host 1:

[saml@host1 testdir]# pwd
/tmp/testdir

[saml@host1 testdir]# ls -l
total 12
-rw-r--r--  1 saml saml 21 May 19 00:21 file1
-rw-r--r--  1 saml saml 48 May 19 00:21 file2
-rw-r--r--  1 saml saml 28 May 19 00:21 file3

[saml@host1 testdir]# tar cvf - . | (ssh host2 "umask 0277; cd /tmp/testdir;tar xvf -")
./
./file1
./file2
./file3
./
./file1
./file2
./file3

on host2:

[samr@host2 testdir]# pwd
/tmp/testdir

[samr@host2 testdir]# ls -l
total 12
-r-------- 1 samr web 21 May 19 00:21 file1
-r-------- 1 samr web 48 May 19 00:21 file2
-r-------- 1 samr web 28 May 19 00:21 file3

You can drop the -v switches to tar which I've included here merely so that you can see the files being tarred up on host1 and sent through STDOUT (aka. -) and then getting un-tarred on host2.

NOTE: Why this works? Tar's default behavior is to unpack files using a remote user's umask. In the above example I've included the command umask to explicitly set it to something different which demonstrates that the remote tar is changing the permissions on the remote side.

Answer 3

I wrote a small script for the task in Python. You can do python script.py -p o+r some files some/dir/on/the/server/

import subprocess
import sys
from optparse import OptionParser


DEFAULT_SERVER = 'your.server.com'

parser = OptionParser()

parser.add_option("-p", "--permissions", action="store", 
                     type="str", dest="perm", metavar="PERM",
                     help="chmod files to PERM", default=None)
parser.add_option("-s", "--server", action="store", 
                     type="str", dest="serv", metavar="SERVER",
                     help="scp to SERVER", default=DEFAULT_SERVER)

options, args = parser.parse_args()
files = args[:-1]
direct = args[-1]

proc = subprocess.Popen(['scp'] + files + ['%s:%s' % (options.serv, direct)],
                        stdout=subprocess.PIPE, stderr=subprocess.PIPE)
if proc.wait() != 0:
    print >>sys.stderr, "Uploading failed!"
    sys.exit(1)

if options.perm is not None:
    arg_dict = dict(dir=direct, perm=options.perm, files=' '.join(files))
    proc = subprocess.Popen(['ssh', options.serv, 'cd %(dir)s;'
                             'chmod -R %(perm)s %(files)s' % arg_dict],
                            stdout=subprocess.PIPE, stderr=subprocess.PIPE)

Answer 4

Assuming you are uploading to a UNIX variant, I think that the permissions ought to follow your UMASK settings. I don't recall off the top of my head which dot-files get processed for SCP, but if you set your UMASK in one of those the files you create will have it's permissions set based on it. It probably depends on what shell you use on the remote system.

Whatever you do, don't use the -p option as it does the exact opposite of what you want.