Understanding Permission Symbols: r, w, x

Permissions and Ownerships

Understanding Permission Symbols: r, w, x

Welcome to this beginner-friendly tutorial on Linux permissions!

In Linux, every file and directory has a set of permissions that define who can read, write, or execute it. These permissions are represented by the letters: r, w, and x.

What do these symbols mean?

  • r (read) – Allows viewing the contents of a file or listing the contents of a directory.
  • w (write) – Allows modifying a file or adding/removing files in a directory.
  • x (execute) – Allows running a file (like a script), or entering a directory.

Let’s see permissions in action

We’ll use the ls -l command to list files along with their permissions.

ls -l
-rwxr-xr--  1 user user  2048 Jul  1 10:00 hello.sh

This output shows a file named hello.sh. Let’s break down the leftmost part: -rwxr-xr--

Permission breakdown

PartMeaning
-It's a file (d for directory, - for regular file)
rwxUser (owner) permissions: read, write, execute
r-xGroup permissions: read, execute (but not write)
r--Others: read only

Try this example yourself

Create a file and check its default permissions:

touch myfile.txt
ls -l myfile.txt
-rw-r--r-- 1 user user 0 Jul  2 11:30 myfile.txt

This means:

  • User can read and write the file
  • Group can only read
  • Others can only read

What about directories?

Directory permissions behave slightly differently:

  • r – Can list directory contents
  • w – Can create/delete files in the directory
  • x – Can enter ("cd into") the directory

Let’s check a directory’s permissions:

mkdir testdir
ls -ld testdir
drwxr-xr-x 2 user user 4096 Jul  2 11:35 testdir

This means:

  • User can list, write, and enter the directory
  • Group and others can read and enter, but not modify

Quick tip: Use chmod to change permissions

For example, to add execute permission for everyone on a file:

chmod +x hello.sh
ls -l hello.sh
-rwxr-xr-x 1 user user 2048 Jul  2 11:40 hello.sh

Now everyone can execute the script!

Summary

Permissions are crucial to keeping your Linux system secure and organized. Knowing what r, w, and x mean will help you control access to your files and directories with confidence.

In upcoming lessons, we'll explore changing permissions using chmod, chown, and symbolic vs numeric modes. Stay tuned!


Permissions and Ownerships❯

  1. 1View File Permissions in Linux
  2. 2Change File Permissions with chmod in Linux
  3. 3How to Use Numeric Mode with chmod in Linux
  4. 4chmod Symbolic Mode in Linux
  5. 5How to Change File Ownership in Linux
  6. 6How to Change Group Ownership Using chgrp in Linux
  7. 7Understanding Linux File Permission Symbols (r, w, x)
  8. 8Linux File Permissions - User, Group, Others
  9. 9Understanding Special Permissions in Linux: SUID, SGID, and Sticky Bit
  10. 10How to Use ACLs in Linux - Set File Permissions
  11. 11Set ACL Permissions in Linux with setfacl
  12. 12How to View ACLs using getfacl in Linux
  13. 13Find Files by Permissions in Linux