linux permissions

erat123 · 05-29-2007, 08:05 PM

Hi, I have a question about file permissions...

I am copying files from my computer to a server. The file on my computer has permissions: -rw-r-r-

when i copy the files, the permissions stay the same, but I would like them to take on a default permission.

so, basically, on my client computer, if i change the files permissions to -rw-rw-r, then permissions for that file on the server will be -rw-rw-r. if i dont change them, then the permissions are -rw-r-r.

i hope this makes sense.

thanks for any help!

troybtj · 05-29-2007, 08:24 PM

change the default umask for the application you are using to copy files (samba, ssh, etc).

for -rw-rw-r--

use umask 0002

More info here: http://www.linuxquestions.org/questi...?postid=869244

If you are using scp to copy files, use the -p option to retain date/time/permissions

A bit more explanation (stolen from google)

By default, and with a umask of 000, files get mode 666 and directories get mode 777. As a result, with a default umask value of 022, newly created files get a default mode 644 (666 - 022 = 644) and directories get a default mode 755 (777 - 022 = 755).

In order to change the umask value, simply use the umask command and give it an octal number. For instance, if you want all new directories to get permissions rwxr-xr--- and files to get permissions rw-r----- by default (modes 750 and 640), you'll need to use a umask value which removes all rights to other, and write permissions to the group : 027. The command to use is:

umask 027

erat123 · 05-29-2007, 08:47 PM

thanks for the quick reply. i've changed my umask from 0022 to 0002 and the same problem is occurring. it's like it's not acknowledging the umask at all. i've also confirmed the umask is changing by logging into an ssh session and running the umask command. i can send some files or give more information if needed.

Thanks!

troybtj · 05-29-2007, 08:56 PM

Did you change it in .profile, .bash_profile, .bashrc ?

I'm not exactly sure which one scp looks at. sftp will use the mask of your login shell.

erat123 · 05-29-2007, 09:02 PM

here is my .bash_profile file. this is the only file i changed. the other files i have are .bash_history, .bash_logout and .bashrc

Code:

# ~/.bash_profile: executed by bash(1) for login shells.
# see /usr/share/doc/bash/examples/startup-files for examples.
# the files are located in the bash-doc package.

# the default umask is set in /etc/login.defs
umask 0002

# include .bashrc if it exists
if [ -f ~/.bashrc ]; then
    . ~/.bashrc
fi

# set PATH so it includes user's private bin if it exists
if [ -d ~/bin ] ; then
    PATH=~/bin:"${PATH}"
fi

troybtj · 05-29-2007, 09:03 PM

Try adding it to .bashrc

If that doesn't work, I'm out of answers.

erat123 · 05-29-2007, 09:21 PM

that didnt work either.

this code in .bash_profile would prevent that from working

Code:

# include .bashrc if it exists
if [ -f ~/.bashrc ]; then
    . ~/.bashrc
fi

thanks for all your help. if you get any more ideas, let me know. if i find the answer, i'll be sure to post it here.

erat123 · 05-29-2007, 09:29 PM

I'm not sure if it helps at all, but I'm using a chroot jail. It's wolfgang's make_chroot_jail.sh

his site is: http://www.fuschlberger.net/programs...t_jail.sh.html

idk why, but the site isnt loading on my computer. the only reason I'm saying this is because I have a copy of a lot of my files, and maybe someone can see a problem.

troybtj · 05-29-2007, 10:36 PM

Quote:

Originally Posted by erat123

that didnt work either.

this code in .bash_profile would prevent that from working

Code:

# include .bashrc if it exists
if [ -f ~/.bashrc ]; then
    . ~/.bashrc
fi

thanks for all your help. if you get any more ideas, let me know. if i find the answer, i'll be sure to post it here.

Not if scp is reading .bashrc and NOT .bash_profile

If it logs in and looks for bashrc, it will get the info from there, not caring what is in .bash_profile

The chroot you have installed may effect this as well, but try adding command to .bashrc and see how it works.

erat123 · 05-29-2007, 11:55 PM

i see what you mean. i gave it a try and loaded umask to .bashrc and it didnt work. i also tried removing it from .bash_profile and keeping it in .bashrc and that didnt work either.

this might be a long shot, but i understand there's something called pam_umask. i've heard it's a replacement to umask. have you heard of that, and if so, do you know if that may work better?

erat123 · 05-30-2007, 12:47 AM

well, i've been doing some research and some trial and error techniques as well. i copied a file from my local pc to my server using the scp command. it did the same thing (ignored the umask)

here is the output:

client side:

Code:

$ ls -l
-rw-rw-r-- 1 eric eric   15 2007-05-29 18:25 test

server side:

Code:

$ ls -l
-rw-r--r-- 1 admin admin 15 2007-05-29 23:42 test

$ umask
0002

I've been looking online and it seems like openssh has a bug in it that prevents this from working well. people claim they have working patches, but i'm not skilled enough to install one or understand the benefits.

troybtj · 05-30-2007, 07:04 AM

Were you trying to force default permissions on the copy, or keep them? To keep permissions, use scp -p

You could use alias scp='scp -p'
so you wouldn't need to add the option each time.

erat123 · 05-30-2007, 11:12 PM

THAT WORKED!! I just got home and tried it out, and all was well! I don't really understand why changing the umask wouldn't fix it, but I'm pretty content with this. Thanks a lot troybtj! You really helped me out a lot!