Scary about “drwxr-xr-x”?

Don’t worry, in 30 seconds you’ll be able to read it!

Chmod always contains three groups, the first is (u)ser, then (g)roup and finally (o)ther (public)

 | 1 | 2 | 3
 | u | g | o
  1. (u)ser: user can (r)ead and (w)rite
  2. (g)roup: user in this same group can (r)ead.
  3. (o)thers/public: can (r)ead and e(x)ecute.
U = User            (1)
G = Group           (2)
O = Other (Public)  (3)

R = Read
W = Write
X = Execute

Give permisions:

chmod ugo+rwx hey.txt

This add permissions to (u)ser, (g)roup and (o)ther to (r)ead, (w)rite and e(x)ecute file hey.txt.

chmod o-r hey.txt

This remove permision for (o)ther to (r)ead.


Now you can read what means “-rwxr-xr--”.

Yes! It’s.

  • (u)ser can (r)ead, (w)rite and e(x)ecute.
  • (g)rupe can (r)ead and e(x)ecute.
  • (o)ther can only (r)ead.

Remeber: -rwx|r-x|r--
Linux have always 3 groups : (u)ser, (g)rups, (o)ther!

  • You can give access to u, g and o.
  • You can give access to (r)ead, (w)rite, and e(x)ecute.

You gave access by adding plus sign (+)

  • you gave (u)ser access to (r)ead and (w)rite to file hello.
    chmod u+rw hello

  • you remove (u)ser access to (r)ead and (w)rite to file hello.
    chmod u-rw hello


first letter are type of file.

d = directory.

That’s it.