How can I exclude all “permission denied” result lines from “grep”?

Question

So, the thing is, I'm on linux terminal using grep command and I want the output without all the lines where it prints at the beginning "grep:" or the lines that begins with "./", because now I'm getting something like this:

grep: ./users/blabla1: Permission denied grep: ./users/blabla2: Permission denied grep: ./users/blabla3: Permission denied grep: ./users/blabla4: Permission denied grep: ./users/blabla5: Permission denied grep: ./users/blabla6: Permission denied grep: ./users/blabla7: Permission denied grep: ./users/blabla8: Permission denied ./foo/bar/log.log ./foo/bar/xml.xml 

I have tried this:

grep -irl "foo" . | grep -v "Permission denied" 

I have also tried this one:

 grep -irl "foo" . | grep -v "^grep:" 

And finally this one:

 grep -irl "foo" . | grep "^./" 

But I keep getting same results as if I haven't put anything after the |, any ideas? What am I missing?

Answer 1

The messages you are receiving is due to a lack of permission on those files, i.e., those are error messages.
All you have to do is to redirect the stderr (standard error output) to /dev/null, like this:

grep -irl "foo" 2> /dev/null 

To lear more about redirection (on bash), read this article: Bash Reference Manual - Redirections

Edit: You can also just suppress error messages by using:

grep -irl "foo" 2>&-