Chmod

TamPepper · 01-15-2012, 07:22 AM

I am trying to change permissions of a file on my PVR.
Currently the permissions are 755 and I wish to make it 777
I telnet into the directory and enter the chmod 777 logo.jpg
It returns read-only file system
How can I change this ?

MartinStrec · 01-15-2012, 07:31 AM

It looks you've insufficient permissions. Are you logged in as 'root'? Try to switch user by 'su' or 'sudo -i' command. Look who is the file owner (I guess it's 'root').

Do not forget, rights 755 it means full access (read/write/execute) for owner, read/execute for owner group, read/execute for everyone else. The conclusion: you can change rights only if you are owner (or superuser).

devUnix · 01-15-2012, 07:46 AM

Have a look at the following commands to understand why you're unable to change the file permissions:

Code:

[test@localhost ~]$ touch /tmp/hi.txt
[test@localhost ~]$ chmod 755 /tmp/hi.txt
[test@localhost ~]$ ls -l /tmp/hi.txt 
-rwxr-xr-x. 1 test test 0 Jan 15 19:14 /tmp/hi.txt
[test@localhost ~]$ logout
[demo@localhost Bash]$ chmod 777 /tmp/hi.txt 
chmod: changing permissions of `/tmp/hi.txt': Operation not permitted
[demo@localhost Bash]$ su - root
Password: 
[root@localhost ~]# chmod 777 /tmp/hi.txt 
[root@localhost ~]# ls -l /tmp/hi.txt 
-rwxrwxrwx. 1 test test 0 Jan 15 19:14 /tmp/hi.txt
[root@localhost ~]#

Note: Only the owner or the Super User i.e. root can change file permissions.

repo · 01-15-2012, 07:49 AM

Quote:

It returns read-only file system

Mount it read/write

Kind regards

TamPepper · 01-15-2012, 08:00 AM

Can I do this from telnet on a Windows 7 box ?

MartinStrec · 01-15-2012, 08:18 AM

Hi,

your file '/tmp/hi.txt' has been created by user 'test' and it has got rights 755 (rwxr-xr-x).

then you ran command 'chmod' as user 'demo'. User 'demo' is not the owner of '/tmp/hi.txt' so that user cannot change mode (chmod).

For more, I look to the documentation and the chmod is allowed just for file owner or superuser. See 'man chmod'.

Just my idea of changing permissions out of owner is to use 'sudo' command if it's necessary. Even you have to configure it to do not ask passwords in that case.

TamPepper · 01-15-2012, 09:01 AM

According to ls -l the file belongs to root and I am logged in as root

repo · 01-15-2012, 09:06 AM

Quote:

It returns read-only file system

You are on a read only filesystem.
Mount it read/write.

Quote:

Can I do this from telnet on a Windows 7 box ?

Do you telnet to or from a windows box?

Kind regards

TamPepper · 01-15-2012, 09:14 AM

From Windows 7 box to the PVR

repo · 01-15-2012, 09:17 AM

Please post the output from

Code:

ls -l
mount

Kind regards

TamPepper · 01-15-2012, 09:30 AM

Is there a tenet command for sending the results to a text file on my C drive (Windows)

repo · 01-15-2012, 09:35 AM

AFAIK you can't
You could try to copy/paste the output from the terminal.

Kind regards

TamPepper · 01-15-2012, 09:43 AM

I "think" I have attached it to this
First ime attempt

vp0619520 · 01-15-2012, 09:45 AM

You are on a read only filesystem.
Try this：

Code:

mount -o remount,rw  /dev/partitionname

devUnix · 01-15-2012, 09:57 AM

Quote:

Originally Posted by vp0619520

You are on a read only filesystem.
Try this：

Code:

mount -o remount,rw  /dev/partitionname

That should work!

Do it as "root".

Code:

[demo@localhost bin]$ touch /media/sf_Books/hello
touch: cannot touch `/media/sf_Books/hello': Read-only file system

[root@localhost ~]# mount -o remount,rw /media/sf_Books/

[demo@localhost bin]$ touch /media/sf_Books/hello
[demo@localhost bin]$ ls -l /media/sf_Books/hello
-rwxrwxrwx. 1 root vboxsf 0 Jan 15 21:25 /media/sf_Books/hello