Playing with Chmod!

What happens when you accidently change the permission of the all important ‘chmod’ command? 

Let’s try it out….

1.            # ls -l /bin/chmod

-rwxr-xr-x. 1 root root 48712 Oct 15  2014 /bin/chmod

2.   # rpm -qf `which chmod`

      coreutils-8.4-37.el6.x86_64

  

3.   # chmod 444 /bin/chmod

4.   # ls -l /bin/chmod

-r--r--r--. 1 root root 48712 Oct 15  2014 /bin/chmod

So, the permission is changed!

5.   # chmod 655 /bin/chmod

  -bash: /bin/chmod: Permission denied

Oooops……Screwed  !!!!! :(

Now is the time to do some rescue stuff…

6. Lets restore it back;

7.   #    install -m 0755 /bin/chmod ./chmod.tmp

      #   ./chmod.tmp 0755 /bin/chmod

8.   # ls -l  /bin/chmod

 -rwxr-xr-x. 1 root root 48712 Oct 15  2014 /bin/chmod

Your all important 'chmod' command is back!

Linux just works ! ;)