How can I have grep not print out 'No such file or directory' errors?

Question

I\'m grepping through a large pile of code managed by git, and whenever I do a grep, I see piles and piles of messages of the form:

> grep pattern * -R -         


        

Answer 1

Errors like that are usually sent to the "standard error" stream, which you can pipe to a file or just make disappear on most commands:

grep pattern * -R -n 2>/dev/null

Answer 2

I usually don't let grep do the recursion itself. There are usually a few directories you want to skip (.git, .svn...)

You can do clever aliases with stances like that one:

find . \( -name .svn -o -name .git \) -prune -o -type f -exec grep -Hn pattern {} \;

It may seem overkill at first glance, but when you need to filter out some patterns it is quite handy.

Answer 3

Have you tried the -0 option in xargs? Something like this:

ls -r1 | xargs -0 grep 'some text'

Answer 4

I was getting lots of these errors running "M-x rgrep" from Emacs on Windows with /Git/usr/bin in my PATH. Apparently in that case, M-x rgrep uses "NUL" (the Windows null device) rather than "/dev/null". I fixed the issue by adding this to .emacs:

;; Prevent issues with the Windows null device (NUL)
;; when using cygwin find with rgrep.
(defadvice grep-compute-defaults (around grep-compute-defaults-advice-null-device)
  "Use cygwin's /dev/null as the null-device."
  (let ((null-device "/dev/null"))
    ad-do-it))
(ad-activate 'grep-compute-defaults)

Answer 5

If you are grepping through a git repository, I'd recommend you use git grep. You don't need to pass in -R or the path.

git grep pattern

That will show all matches from your current directory down.

Answer 6

You can use the -s or --no-messages flag to suppress errors.

-s, --no-messages suppress error messages

grep pattern * -s -R -n