What does the number 750 represent in the 'chmod' command?

In the chmod command, the number 750 represents a specific set of permissions for a file or directory in Linux. Each digit in the number corresponds to different permission levels for the owner, group, and others. Here's the breakdown:

• First Digit (7): This represents the permissions for the owner of the file.

  • 7 means the owner has read (4), write (2), and execute (1) permissions.
  • So, 4 + 2 + 1 = 7.

• Second Digit (5): This represents the permissions for the group associated with the file.

  • 5 means the group has read (4) and execute (1) permissions, but not write permission.
  • So, 4 + 0 + 1 = 5.

• Third Digit (0): This represents the permissions for others (everyone else).

  • 0 means others have no permissions at all.

Summary

So, chmod 750 filename sets the permissions as follows:

• Owner: Read, Write, Execute (7)
• Group: Read, Execute (5)
• Others: No permissions (0)

Example

If you run:

chmod 750 myfile

The owner can read, write, and execute myfile, the group can read and execute it, and others cannot access it at all.

Further Learning

To explore more about file permissions and the chmod command, consider checking out relevant LabEx labs on Linux permissions.

If you have any more questions or need clarification, feel free to ask! Your feedback is always welcome.