Why does "redirect to a file" is executed as user, even with sudo?

Question

I often encouter this problem and it really bugs me on why it is so. So let's take this example into account :

[me@localhost:~]$ sudo command > /some/file.log

As far as I know, this will not work if the user has no permission to write in /some/file.log, even if the command is executed as sudo. I found some workarounds on this website so that's not a problem, but I would like to know what is the reason behind it ? Why would the command be executed as sudo, and the redirection as user ? Any solid reason to back this up ?

As said in my post, I already knew how to make this work properly. My question was more about why is that so, and Anthon gave me the reason :) — , Oct 27 '14 at 21:21
@eyoung100 did you test that. I can not see how it can work, so I tested it, and it did not. — ctrl-alt-delor, Oct 27 '14 at 21:21
@eyoung100 you just repeated the command, that does not work, that was in your earlier comment (that you deleted). — ctrl-alt-delor, Oct 27 '14 at 21:37
I changed the directory to root, but I'll delete them both. — eyoung100, Oct 27 '14 at 21:41

score 1 · Accepted Answer · answered Oct 27 '14 at 20:55

You sudo the command command, the redirection of the output to /some/file.log is done by your current shell, which is running as the normal user.

What you could try in order to get the output written by root is:

sudo bash -c "command > /some/file.log"

Why does "redirect to a file" is executed as user, even with sudo?

1 Answers1