# LINUX: chmod & chown — The File & Folder Access Control

chmod and chown are among those popular Linux commands.

chmod: To modify access to files and folders by providing read/write/execute permissions.  
chown: To change the ownership of a file or folder.

# **chmod**

There are two ways in which the permissions can be changed/set.

The symbolic method is the one where we mention:

Example :  
To remove read and write permission from the group and other of file “myfile.txt”

```bash
chmod og-rw myfile.txt
```

To add execute permission to group of the file “myfile2.txt”

```bash
chmod g+x myfile2.txt
```

The numeric method (my personal favorite) adds up the numbers to determine what kind of permission a file should have:

Now here’s the magic:

1 = execute (1)  
2 = write (2)  
3 = write (2) + execute (1)  
4 = read (4)  
5 = read (4) + execute (1)  
6 = read (4) + write (2)  
7 = read (4) + write (2) + execute (1)

![](https://cdn.hashnode.com/res/hashnode/image/upload/v1693327763371/0a210921-6a5e-4d4a-8cde-363cddc5d429.png align="center")

And the only extra thing to remember is the sequence of permission, it’s always  
User -> Group -> Others

Example:  
To set the permission for a file “myfile2.txt” such as:  
a. User has full (read, write, and execute) permission …*(read+write+execute = 4+2+1 = 7)*  
b. Group has read and write permission …*(read+write = 4+2 = 6)*  
c. Others have only read permission …*(read = 4)*

```bash
chmod 764 myfile2.txt
```

*Note: 777 is a very dangerous way to give permission, this gives everyone in the world full control over file.*

# **chown**

chown is pretty straightforward. Just remember that the syntax used for ownership is **owner:group**

Here are a few examples:

To make a user named bob the owner of a folder called MyDirectory:

```bash
chown bob MyFolder
```

To make a group name myGroup the owner of MyDirectory folder (notice the colon before group name, remember the owner:group pattern):

```bash
chown :myGroup MyDirectory
```

To make a user named john and a group named group2 the owner of folder MyDirectory:

```bash
chown john:group2 MyDirectory
```