CITS2002 Systems Programming  
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Describing permissions using octal values

While we know that all data within a computer is stored in binary, we do not refer to or describe system-focused values with ones-and-zeroes.

In the case of file-system permissions, 3 bits (ranging over the integer values 0..7) are used to store Boolean values for the read, write, and execute permissions.

Further, 3 sets of these 3 permissions bits, one for each of the user, group, and 'other' owners are employed for each file-system entry.

So, while we don't describe these data values in binary, it makes a lot of sense to describe them using octal values:

You may also like to try the Unix Permissions Calculator.

 

CITS2002 Systems Programming, Lecture 16, p10, 19th September 2023.