Stting Standard File Permissions
List, Set and Change Standard File Permissions
chmod
: Used to change the read, write and execute privileges of a file or directory for the owner, the group(s) they belong to, and all others (often called everyone)chmod 777 somefile.txt
: This would change the file somefile.txt to read/write/execute for the owner, the group belonged to, and everyone else (universal permissions)- Numeric and character values for the permissions are as follows:
r – 4
– Read permissionsw – 2
– Write permissionsx – 1
– Execute permissions- Adding these values together determines the privilege number
- Example:
chmod 755 somefile.txt
- User: read (4) + write (2) + execute (1) = 7
- Group: read (4) + execute (1) = 5
- Everyone: read (4) + execute (1) = 5
- Permissions can also be changed by single category using character representation
- Example:
chmod g+rw somefile.txt
- Adds group permissions of read and write to the file called
somefile.txt
- Character values as follows:
u
– Userg
– Groupa
– Everyoner
– Readw
– Writex
– Execute+
– Add the values indicated-
– Remove the values indicated
chown
: Change ownership to a specific user and/or groupchgrp
: Change group ownership to a specific group