File Permission 660

A break down of file permissions with an octal value of 660
and a symbolic value of -rw-rw----

Octal Value


An "Octal Value" or "Number Value" of a file permission is simply a numeric value, composed of 3 or 4 digits, each one ranging in value from 0 - 7, that represents access grated to users on the system. These octal values, can be used to change or manage a file or directory's permissions, using a well known command-line-utility called chmod. Obtaining a specified "Octal Value" usually starts with a file's "Symbolic Value", and transmuting it to it's corresponding number value. In this case, ---x--x--x converted to it's Octal or Number value is 111. For further information on how to transpose file permission's symbolic values to their octal counter part; or to get a better grasp on "Octal Notation" in general, see our guide on the subject - How to Understanding Octal Notation.

Symbolic Value


File Permission's "Symbolic Value", or "Symbolic Notation", is a string made up of 10 characters that represents access granted to users on the system. Each "Symbolic Value" string is broken down into 4 sections. The file type (file or directory), Owner, Group, and Other in that order. The file is the first character (either d or -), while each of the subsequent groups (owner, group, and other) are represented by each subsequent cluster of three characters. In short, a "Symbolic Value" is the "string" based counterpart of a corresponding "Octal Value". In this case, 660 converted to its symbolic counterpart is "-rw-rw----". If you're looking for info on how to obtain a symbolic value, or how to transpose an octal value to symbolic notation see our guide on the subject - How to Understanding Symbolic Notation


File, as denoted by the leading "-" within it's symbolic value -rw-rw----
See Directory Counterpart

File Directory
Yes No

Permissions Breakdown

User Group Other
Read Yes Yes No
Write Yes Yes No
Execute No No No


Octal permissions can be made up of either 3 or 4 values. In the case of "660", a 3 digit octal number, a leading value has not been set, so 660 only represents permissions for User, Group and Other. So in this case a Sticky Bit, SUID or SGID, have not, and cannot be set.

If you wish to set a Stick Bit, SUID, or SGID you can start by reading our guide on the matter, here.
Sticky Bit SGID SUID
No No No

How to change your file to 660 or -rw-rw---- using chmod

Chmod is a well known command line utility, that's used to manage file permissions on MacOS, Linux and other Unix like operating systems. While there are multiple ways to use chmod, on this site, we have chosen to focus exclusively on using chmod with Octal Notation. The following examples illustrate exactly how to change your desired file to permissions matching "660 or -rw-rw----" using the command line and chmod. If you're lost on how to manually manage file permissions, see our guide - How Do I Change File Permissions Using chmod?

From your terminal run the following command, within a directory containing the file you wish to change permissions on. In this case the filename is "yourfile.txt"
$ chmod 660 yourfile.txt
Confirming your change, your file's symbolic permissions should now be "-rw-rw----"
$ ls -l

# your output will be similar to the following
-rw-rw---- 14 root root 4096 Jun 22 07:36 yourfile.txt