Add find command

Signed-off-by: Oliver Davies <oliver@oliverdavies.uk>

internal/lib/zet.go

@@ -43,6 +43,39 @@ func GetAllZets(dir string) []int {
 	return sorted
 }
 
+func SearchZets(dir string, query string) []int {
+	zets, err := execGitCommand(dir, "grep", "-i", "--name-only", "--word-regex", query)
+
+	if err != nil {
+		fmt.Printf("No matches found for %s.\n", query)
+
+		os.Exit(1)
+	}
+
+	re := regexp.MustCompile(`[0-9]+`)
+	matches := re.FindAllString(zets, -1)
+
+	sort.Strings(matches)
+
+	ids := make(map[int]struct{})
+	for _, id := range matches {
+		num, err := strconv.Atoi(id)
+
+		if err == nil {
+			ids[num] = struct{}{}
+		}
+	}
+
+	var sorted []int
+	for num := range ids {
+		sorted = append(sorted, num)
+	}
+
+	sort.Ints(sorted)
+
+	return sorted
+}
+
 func ParseZetList(ids []int) []string {
 	var lines []string