Cannot set file permissions

Question

I am trying to set file permissions for a folder named Sales. I am doing a school project and I want to give a tutorial regarding file permissions.

I am using vmware workstation and when I go on Sales permissions and try to set a file permission, it will return to -.

Also, I cannot tick to execute the file as a program :S...

When I try to do so the tick will also automatically vanish.

This is rather strange but don't know what is going on.

Answer 1

Open a terminal, and to give the executive flag, do this :

chmod +x a.sh

where a.sh is the file that you want to be executable.

To change read, or write permission, do this:

chmod -r a.sh # make it non-readable
chmod +r a.sh # make it readable
chmod -w a.sh # make it non-writeable
chmod +w a.sh # make it writeable

As every file belongs to a user and belongs to a group, you can be specific to user, group or everybody prefixing the permission option with the letters u, g and o respectively. So you could:

chmod g+w a.sh # make it writeable by the group a.sh belongs
chmod o-w a.sh # make it non-writeable by others than the user and the group a.sh belongs
chmod g+w,o-w a.sh # The same as the two lines before, but in one line

For more options, check man chmod

Answer 2

to remove read write and execute permissions

% chmod go-rwx (file name)

To give read and write permissions (all file)

% chmod a+rw ur filename

   
    Symbol
    Meaning
  
   
    u
    user
  
   
    g
    group
  
   
    o
    other
  
   
    a
    all
  
   
    r
    read
  
   
    w
    write (and delete)
  
   
    x
    execute (and access directory) 
  
   
    +
    add permission
  
   
    -
    take away permission
  

Answer 3

Please clarify. Which version of Ubuntu are you using? Are you using the GUI to edit these permissions? (You mentioned a 'tick'.)
You said you are using VMWare. Is this folder on the same Virtual Machine? Or on the Host/Network, etc.?
Last but not least, Do you own the folder? Only the owner (or root) can change the permissions on a file or folder.

Also to expand on Vjo's answer. The instructions he gave you will apply the permissions 'across the board' to the user, group and all others. If you want to be more specific as to who you are applying the permissions to you can also use u, g + o to assign those rights to the user(u), the group(g), or others(o)

For example:

chmod u+x filename

Would add execute permissions to the 'filename' file for the user only. If you wanted to add write(w) permissions to the user(u) and group(g), then you could use:

chmod ug+w filename

Plus(+) adds the permission, Minus(-) removes the permissions, and Equal (=) sets the permission.