How do I find files that do not contain a given string pattern?

 

If your grep has the -L (or --files-without-match) option:

$ grep -riL "foo" * 

     -L, --files-without-match
             each file processed.
     -R, -r, --recursive
             Recursively search subdirectories listed.

     -i, --ignore-case
             Perform case insensitive matching.

If you use l (lowercased) you will get the opposite (files with matches)

-l, --files-with-matches Only the names of files containing selected lines are written