# ack > A search tool like `grep`, optimized for developers. > See also: `rg`, which is much faster. > More information: . - Search for files containing a string or regular expression in the current directory recursively: `ack "{{search_pattern}}"` - Search for a case-insensitive pattern: `ack --ignore-case "{{search_pattern}}"` - Search for lines matching a pattern, printing [o]nly the matched text and not the rest of the line: `ack -o "{{search_pattern}}"` - Limit search to files of a specific type: `ack --type={{ruby}} "{{search_pattern}}"` - Do not search in files of a specific type: `ack --type=no{{ruby}} "{{search_pattern}}"` - Count the total number of matches found: `ack --count --no-filename "{{search_pattern}}"` - Print the file names and the number of matches for each file only: `ack --count --files-with-matches "{{search_pattern}}"` - List all the values that can be used with `--type`: `ack --help-types`