Take the 2-minute tour ×
Unix & Linux Stack Exchange is a question and answer site for users of Linux, FreeBSD and other Un*x-like operating systems.. It's 100% free, no registration required.

Why does redirection, using sudo give me an error for the following commands?

$ sudo printf "foo" >/etc/file
bash: /etc/file: Permission denied

$ sudo printf "foo" ~/file; cat ~file >/etc/file 
bash: /etc/file: Permission denied

...yet I have no such problem when I use an editor, or cp.
I don't think I've ever tried this before, so I don't know if there is something haywire on my system, or if this is normal. It seems a bit restrictive to be normal, but(?) maybe it is intended to be restrictive... (using Ubuntu)

share|improve this question

1 Answer 1

up vote 15 down vote accepted

It is normal. The file after the > is not open by the process running under sudo, but by the shell, which isn't. Try this instead:

printf "foo" | sudo tee /etc/file
share|improve this answer
1  
Got it, thanks.. so this works too, sudo sh -c 'printf "foo" >/etc/file' –  Peter.O Aug 30 '11 at 3:37
1  
Also, as mentioned in the Q/A linked to by Gilles comment, tee -a caters for appending to a file... –  Peter.O Aug 30 '11 at 12:15

Your Answer

 
discard

By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.