On Tue, May 12, 2015 at 9:24 AM, Iruatã Souza <iru.muzgo@gmail.com> wrote:

--r-------- d 0 glenda glenda 0 May 10 18:57 0
--rw------- d 0 glenda glenda 0 May 10 18:57 1
---w------- d 0 glenda glenda 0 May 10 18:57 2

is that what you want to know? or the reasons why the permissions are like that?

I want to understand the system. (It makes sense to me that the permissions are like that.)

What is the relationship between file descriptor 1 and /fd/1? When a program runs, 1 is already open for writing. But apparently it's open only for writing. A read on it yields inappropriate use of fd. The same seems to happen /fd/1. Can I say they'll both always present the same behavior?

I'm not able to change permissions on /fd/1. Why not?

% ls -l /fd/1

---w------- d 0 dbastos dbastos 0 May 19 2014 /fd/1

% chmod u+r /fd/1

chmod: can't wstat /fd/1: permission denied

I'm studying. One thing I imagined was to write to standard output and be able to read what I wrote.