- 1View File Permissions in Linux
- 2Change File Permissions with chmod in Linux
- 3How to Use Numeric Mode with chmod in Linux
- 4chmod Symbolic Mode in Linux
- 5How to Change File Ownership in Linux
- 6How to Change Group Ownership Using chgrp in Linux
- 7Understanding Linux File Permission Symbols (r, w, x)
- 8Linux File Permissions - User, Group, Others
- 9Understanding Special Permissions in Linux: SUID, SGID, and Sticky Bit
- 10How to Use ACLs in Linux - Set File Permissions
- 11Set ACL Permissions in Linux with setfacl
- 12How to View ACLs using getfacl in Linux
- 13Find Files by Permissions in Linux
Understanding Permission Symbols: r, w, x
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
| Part | Meaning |
|---|---|
| - | It's a file (d for directory, - for regular file) |
| rwx | User (owner) permissions: read, write, execute |
| r-x | Group 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!
Next Topic ⮕Linux File Permissions - User, Group, Others
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