lib/pre-commit/checks/grep.rb in pre-commit-0.38.0 vs lib/pre-commit/checks/grep.rb in pre-commit-0.38.1

@@ -91,14 +91,15 @@
           %w{grep -PnIH}
         end
       end
 
       def detect_grep_version
-        first_line = Open3.popen2('grep', '--version') do |_, stdout, _|
-          stdout.readline
-        end
+        Open3.popen3('grep', '--version') do |_, stdout, _|
+          return '' if stdout.eof?
 
-        first_line.sub(/^[^0-9.]*\([0-9.]*\)$/, '\1')
+          first_line = stdout.readline
+          return first_line.sub(/^[^0-9.]*\([0-9.]*\)$/, '\1')
+        end
       end
 
       def extra_execute(files)
         return nil if extra_pattern.nil? or extra_pattern.empty?
         args = grep + [extra_pattern] + files