On Tue, May 12, 2015 at 9:24 AM, Iruatã Souza 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.