What is the meaning of 0o777 as value of mode of mkdir?

Question

I would like to use mkdir in python.

It has a parameter mode, whose default value is '0o777'.

I know file mode 0777 in Linux. However I don't know what o between 0 and 777 is. What is it?

Nothing a quick tour through [the Python documentation](https://docs.python.org/) would help you solve. And, you should already be able to *guess* what it means (especially if you understand what `0777` is for kind of number, and know about hexadecimal notation). — Some programmer dude, Oct 04 '17 at 10:14
@Someprogrammerdude would *not* help you solve (unless you're trying to denounce the Python docs) — mkrieger1, Oct 04 '17 at 10:42
Precise documentation link: https://docs.python.org/3/library/functions.html#oct — Jean Monet, Jun 22 '22 at 14:40

hspandher · Accepted Answer · 2017-10-04T10:21:13.603

11

It is a Python friendly way of expressing file permissions, using octal numbers.

>>> 0o777
511

edited Oct 04 '17 at 10:21

answered Oct 04 '17 at 10:15

hspandher

2

*- But... I still don't know what 'o' between '0' and '777' is. What is it?* – vaultah Oct 04 '17 at 10:17
3

`o` signifies that the number is an octal number. – hspandher Oct 04 '17 at 10:21
@hspandher: thank you for answering it. I will refer to python document for more detail later. – mora Oct 04 '17 at 10:24
2

@mora Earlier versions of Python didn't use the "o", but that caused problems for some people who tried to interpret decimal numbers with leading zeroes. So it got changed. – PM 2Ring Oct 04 '17 at 10:26
6

for future readers: in 0o777 the `o` stands for "octal", like the `x` in 0xFF stands for "hexadecimal". In linux file permissions the interpreter assumes that the number given is in octal numbering – Torge Rosendahl Feb 16 '21 at 08:33

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