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Chofoteddy
Asked: 2020-12-17 11:49:54 +0800 CST 2020-12-17 11:49:54 +0800 CST

What is the difference between chown and chmod?

  • 772

I am interested in knowing the difference between these to know when to use which one? In the case that I need to modify the permissions of a directory or file on my localhost .

Note: I have read several topics in Spanish but I perceive that they explain in a banal way, I find better information in English but I do not fully understand them.

In the end I end up solving it with something that I consider "nacade" but it works:

$ sudo chmod 777 -R /ruta/

Although after time I have already tired of this solution and I prefer to do it correctly.

bash

5 Answers

  1. Best Answer

    chmodis to change the permissions (from English change mod e )

    chownIt is to change the owner (from the English change own er )

    To change permissions use the first one.

    Permissions are represented by flags that indicate whether the permission is set or not:

    rread _ _

    wwrite _ _

    xexecution _ _

    If the permission is not set, a dash appears-

    And they are grouped into three levels:

    • Permits for the owner
    • Group permissions
    • Permits for the rest.

    Additionally the first letter denotes if it is a directory or not

    So a file that had all permissions would look like this:

    -rwxrwxrwx  3  tu   tugrupo 123 Dec 15 11:11 algun.archivo

    And one that did not have any permissions would look like this:

    ----------  3  tu   tugrupo 123 Dec 15 11:11 algun.archivo

    The chmod command can receive as an argument a number that represents each group of permissions, for example

    chmod 777 archivo

    Gives all permissions to the file

    Each permission group can be thought of as a binary number.

    For example no permission would be 0

    0 = --- ( como el 000 binario )

    run only would be 1

    1 = --x ( como el 001 binario)

    write only, 2

    2 = -w- ( como el 010 binario )

    write and execute, 3

    3 = -wx ( como el 011 binario )

    read only, 4

    4 = r-- (como el 100 binario)

    read and execute, 5

    5 = r-x (como el 101 binario)

    reading and writing, 6

    6 = rw- (como el 110 binario)

    All permissions, 7

    7 = rwx ( como el 111 binario )

    Another example: all permissions for the owner ( 7=rwx) read and execute for the group ( 5=r-x) and read-only for the rest ( 4=r--) will be specified like this:

     chmod 754 archivo

    It is also possible to set and remove specific permissions using the format:

    quien +/- permiso

    Where who is ufor the owner ( user ) or gfor the group and ofor the rest (others)

    So if you wanted to remove the write permission for others you can write:

    chmod o-w archivo

    I read it as: chmod other less write file

    Or to add execute permission to the owner

    chmod u+x archivo

    chmod user plus execute file

    If the "who" is not specified, the add or remove applies to the three groups, so that everyone can read it would be

    chmod +r archivo
    • 14

  2. Change mode ( chmod), changes the access permissions (read, write and execute. r, wand xrespectively):

    $ touch archivo
$ ls -la archivo
-rw-rw-r-- 1 cesar cesar    0 dic 16 14:53 archivo
$ chmod a+x archivo
$ ls -la archivo 
-rwxrwxr-x 1 cesar cesar 0 dic 16 14:53 archivo

    In the example above I added execute permissions ( x) to everyone (user, group and others) usinga

    Change owner ( chown) change to the owners (users, groups):

    $ touch archivo
$ ls -la archivo 
-rw-rw-r-- 1 cesar cesar 0 dic 16 14:55 archivo
$ chown juan:juan archivo
$ ls -la archivo
-rw-rw-r-- 1 juan juan 0 dic 16 14:55 archivo

    In the example above I changed the user:groupto file from cesar:cesartojuan:juan

    • 5

  3. The chown command is used to change a file's owner and user group information, the chmod command is used to change file access permissions such as write, read, and execute.

    For example:

    chown usuario:grupo archivo
chown -R usuario:grupo carpeta 

chmod 777 archivo.txt

    Assign all permissions to the filearchivo.txt 

    chmod 666

    Assign read and write permissions, not execution permissions, to all the files and directories of the directory where we execute the command.

    chmod -R 644

    This gives permissions to all files and directories in the directory where the command is invoked and in all directories that hang from it. The assigned permissions are read to all users, write only to the owner of the file, and execute to no one.

    • 4

  4. chown- change the user and group owners of files

    chmod- change file access permissions

    If you want to modify the permissions on a certain group or a certain user, you can use chmodgiving the corresponding permissions.

    Now in the case that the permissions are correctly assigned for example, but you decide that the directory or file no longer belongs to a certain user or group, you do it by changing it throughchown

    • 3

  5. Easy.

    chmod allows you to change write, read, and execute permissions for a file or directory. While chown allows you to change the owner of the file or directory.

    Examples for chmod:

    Give all permissions to the file.

    $ chmod 777 miarchivo.txt

    Give execution permissions

    $ chmod +x miarchivo.txt

    Remove read and write permissions to the group

    $ chmod g-r-w miarchivo.txt

    Examples for chown:

    change owner

    $ chown root miarchivo.txt

    Change the user owner in the developers group

    $ chown user:developers miarchivo
    • 3