what does -wrxr-xr-x mean

Daniel Parker

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17-03-2025

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Understanding Linux file permissions is crucial for anyone working with the operating system. One of the most common permission sets you'll encounter is -rw-r--r--. But what does it actually mean? This article will break down the meaning of this permission string and how it affects file access.

Deconstructing the Permission String: -rw-r--r--

The string -rw-r--r-- represents the access permissions for a file in the Linux file system. Let's dissect each part:

• The First Character (-): This hyphen indicates that the entry represents a regular file. If it were a 'd', it would be a directory. Other characters represent other file types (like links or sockets).

• The Next Three Characters (rw-): These represent the permissions for the owner of the file:

  • r: Read permission – the owner can read the file's contents.
  • w: Write permission – the owner can modify the file.
  • -: Execute permission – the owner cannot execute the file as a program.

• The Next Three Characters (r--): These represent the permissions for the group associated with the file:

  • r: Read permission – members of the group can read the file.
  • -: Write permission – members of the group cannot modify the file.
  • -: Execute permission – members of the group cannot execute the file.

• The Last Three Characters (r--): These represent the permissions for others (users who are neither the owner nor in the group):

  • r: Read permission – everyone else can read the file.
  • -: Write permission – everyone else cannot modify the file.
  • -: Execute permission – everyone else cannot execute the file.

In summary, -rw-r--r-- grants:

• Owner: Read and write access.
• Group: Read access only.
• Others: Read access only.

How to Check File Permissions

You can check a file's permissions using the ls -l command in your Linux terminal. For example:

ls -l myfile.txt

This will output a detailed listing of your files, including their permissions.

Changing File Permissions

You can modify file permissions using the chmod command. For example, to change myfile.txt to only allow the owner to read and write, you would use:

chmod 600 myfile.txt

The numbers represent octal values corresponding to the permissions:

• 6: Read (4) + Write (2)
• 0: No permissions
• 0: No permissions

This is equivalent to -rw-------

Practical Implications

Understanding file permissions is crucial for security. Granting only necessary access prevents unauthorized modifications or deletions. Overly permissive settings can create security vulnerabilities. Carefully consider the permissions you assign to your files to maintain data integrity and system security.

Further Exploration

For more advanced control over file access, explore the concepts of Access Control Lists (ACLs) in Linux. ACLs provide finer-grained permission control beyond the basic owner, group, and others model. They allow you to grant specific permissions to individual users or groups.

Understanding file permissions is a fundamental aspect of Linux administration and security. Mastering this concept significantly enhances your ability to manage your system effectively.