====== CHOWN Examples ======
<color darkorange>2016</color>
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CHOWN is the Linux **CH**ange **OWN**er Command. This allows the owner of a file or directory to be changed between users.
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==== Change the owner of a file ====
    # ls -lart tmpfile    [ls is used to diplay the file/directory properties]
    -rw-r--r-- 1 himanshu family 0 2012-05-22 20:03 tmpfile
    
    # chown root tmpfile
    
    # ls -l tmpfile
    -rw-r--r-- 1 root family 0 2012-05-22 20:03 tmpfile
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==== Change the group of a file ====
    Through the chown command, the group (that a file belongs to) can also be changed.
    # ls -l tmpfile
    -rw-r--r-- 1 himanshu family 0 2012-05-22 20:03 tmpfile
    
    # chown :friends tmpfile
    
    # ls -l tmpfile
    -rw-r--r-- 1 himanshu friends 0 2012-05-22 20:03 tmpfile
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==== Change both owner and the group ====
    # ls -l tmpfile
    -rw-r--r-- 1 root family 0 2012-05-22 20:03 tmpfile
    
    # chown himanshu:friends tmpfile
    
    # ls -l tmpfile
    -rw-r--r-- 1 himanshu friends 0 2012-05-22 20:03 tmpfile
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==== Change owner only if a file is owned by a particular user ====
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Using chown “–from” flag, you can change the owner of a file, only if that file is already owned by a particular owner.
    # ls -l tmpfile
    -rw-r--r-- 1 root friends 0 2012-05-22 20:03 tmpfile
    
    # chown --from=guest himanshu tmpfile
    
    # ls -l tmpfile
    -rw-r--r-- 1 root friends 0 2012-05-22 20:03 tmpfile
    
    # chown --from=root himanshu tmpfile
    
    # ls -l tmpfile
    -rw-r--r-- 1 himanshu friends 0 2012-05-22 20:03 tmpfile

  * In the example above, we verified that the original owner/group of the file ‘tmpfile’ was root/friends.
  * Next we used the ‘–from’ flag to change the owner to ‘himanshu’ but only if the existing owner is ‘guest’.
  * Now, as the existing owner was not ‘guest’. So, the command failed to change the owner of the file.
  * Next we tried to change the owner if the existing owner is ‘root’ (which was true) and this time command was successful and the owner was changed to ‘himanshu’.
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==== Copy the owner/group settings from one file to another ====
    This is possible by using the ‘–reference’ flag.
    
    # ls -l file
    -rwxr-xr-x 1 himanshu family 8968 2012-04-09 07:10 file
    
    # ls -l tmpfile
    -rw-r--r-- 1 root friends 0 2012-05-22 20:03 tmpfile
    
    # chown --reference=file tmpfile
    
    # ls -l tmpfile
    -rw-r--r-- 1 himanshu family 0 2012-05-22 20:03 tmpfile
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In the above example, we first checked the owner/group of the reference-file ‘file’ and then checked the owner/group of the target-file ‘tmpfile’. Both were different.  Then we used the chown command with the ‘–reference’ option to apply the owner/group settings from the reference file to the target file. The command was successful and the owner/group settings of ‘tmpfile’ were made similar to the ‘file’
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==== List all the changes made by the chown command ====
    Use the verbose option -v, which will display whether the ownership of the file was changed 
    or retained as shown below.
    
    # chown -v -R guest:friends linux
    changed ownership of `linux/redhat/rh7' to guest:friends
    changed ownership of `linux/redhat' retained to guest:friends
    ownership of `linux/redhat_sym' retained as guest:friends
    ownership of `linux/ubuntu_sym' retained as guest:friends
    changed ownership of `linux/linuxKernel' to guest:friends
    changed ownership of `linux/ubuntu/ub10' to guest:friends
    ownership of `linux/ubuntu' retained as guest:friends
    ownership of `linux' retained as guest:friends
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