args are OUTD IND {} patterns..

main.go

@@ -2,8 +2,8 @@ package main
 
 import (
 	"context"
+	"encoding/json"
 	"fmt"
-	"maps"
 	"os"
 	"os/signal"
 	"path"
@@ -12,26 +12,38 @@ import (
 	"syscall"
 )
 
+type Fields struct {
+	Title   string
+	Season  string
+	Episode string
+}
+
 func main() {
 	ctx, can := signal.NotifyContext(context.Background(), syscall.SIGINT)
 	defer can()
 
+	var overrides Fields
+	json.Unmarshal([]byte(os.Args[3]), &overrides)
+
 	if err := Run(ctx,
 		os.Args[1],
 		os.Args[2],
-		os.Args[3:],
+		os.Args[4:],
-		nil,
+		overrides,
 	); err != nil {
 		panic(err)
 	}
 }
 
-func Run(ctx context.Context, outd, ind string, patterns []string, overrides map[string]string) error {
+func Run(ctx context.Context, outd, ind string, patterns []string, overrides Fields) error {
 	entries, err := os.ReadDir(ind)
 	if err != nil {
 		return err
 	}
 	for _, entry := range entries {
+		if !entry.Type().IsRegular() {
+			continue
+		}
 		if err := one(ctx, outd, path.Join(ind, entry.Name()), patterns, overrides); err != nil {
 			return err
 		}
@@ -39,7 +51,7 @@ func Run(ctx context.Context, outd, ind string, patterns []string, overrides map
 	return nil
 }
 
-func one(ctx context.Context, outd, inf string, patterns []string, overrides map[string]string) error {
+func one(ctx context.Context, outd, inf string, patterns []string, overrides Fields) error {
 	f := path.Base(inf)
 	for _, pattern := range patterns {
 		re := regexp.MustCompile(pattern)
@@ -47,30 +59,38 @@ func one(ctx context.Context, outd, inf string, patterns []string, overrides map
 			continue
 		}
 
-		found := maps.Clone(overrides)
+		found := overrides
 		groupNames := re.SubexpNames()
 		groups := re.FindStringSubmatch(f)
 		for i := 1; i < len(groupNames); i++ {
-			k := groupNames[i]
 			v := groups[i]
-			found[k] = v
+			switch groupNames[i] {
+			case "title":
+				found.Title = v
+			case "season":
+				found.Season = v
+			case "episode":
+				found.Episode = v
+			default:
+				return fmt.Errorf("unexpected capture group %q", groupNames[i])
+			}
 		}
 
-		if found["title"] == "" || found["season"] == "" || found["episode"] == "" {
+		if found.Title == "" || found.Season == "" || found.Episode == "" {
 			continue
 		}
-		found["title"] = strings.Join(strings.Fields(found["title"]), "_")
+		found.Title = strings.Join(strings.Fields(found.Title), "_")
 
-		if err := mvNLn(ctx, outd, inf, found["title"], found["season"], found["episode"]); err != nil {
+		return mvNLn(ctx, outd, inf, found)
-			return err
-		}
-		return nil
 	}
 	return nil
 }
 
-func mvNLn(ctx context.Context, outd, inf string, title, season, episode string) error {
+func mvNLn(ctx context.Context, outd, inf string, fields Fields) error {
-	outf := path.Join(outd, fmt.Sprintf("%s_S%sE%s%s", title, season, episode, path.Ext(inf)))
+	outf := path.Join(outd, fmt.Sprintf("%s_S%sE%s%s", fields.Title, fields.Season, fields.Episode, path.Ext(inf)))
+	if _, err := os.Stat(outf); err == nil {
+		return nil // fmt.Errorf("conflict: %s already exists", path.Base(outf))
+	}
 	if err := os.Rename(inf, outf); err != nil {
 		return err
 	}

main_test.go

@@ -15,7 +15,7 @@ func TestRun(t *testing.T) {
 	cases := map[string]struct {
 		given     []string
 		patterns  []string
-		overrides map[string]string
+		overrides main.Fields
 		want      []string
 	}{
 		"empty": {},
@@ -29,8 +29,8 @@ func TestRun(t *testing.T) {
 				".urvivor.[Aa][Uu].*[sS](?P<season>[0-9]+)[eE](?P<episode>[0-9]*).*1080.*MeGusta",
 				".urvivor.[Aa][Uu].*[sS](?P<season>[0-9]+)[eE](?P<episode>[0-9]*).*720.*MeGusta",
 			},
-			overrides: map[string]string{
+			overrides: main.Fields{
-				"title": "Australian_Survivor",
+				Title: "Australian_Survivor",
 			},
 			want: []string{
 				"Australian_Survivor_S12E11.mkv",
@@ -45,8 +45,8 @@ func TestRun(t *testing.T) {
 			patterns: []string{
 				`^\[[^\]]*\] (?P<title>.*) - (?<episode>[0-9]*)`,
 			},
-			overrides: map[string]string{
+			overrides: main.Fields{
-				"season": "01",
+				Season: "01",
 			},
 			want: []string{
 				"Tokidoki_Bosotto_Russia-go_de_Dereru_Tonari_no_Alya-san_S01E01.mkv",
@@ -65,7 +65,9 @@ func TestRun(t *testing.T) {
 			outd := t.TempDir()
 
 			if err := main.Run(context.Background(), outd, ind, c.patterns, c.overrides); err != nil {
-				t.Fatal(err)
+				t.Fatal("err on first run:", err)
+			} else if err := main.Run(context.Background(), outd, ind, c.patterns, c.overrides); err != nil {
+				t.Fatal("err on second run:", err)
 			}
 
 			for _, f := range c.want {
@@ -84,20 +86,8 @@ func TestRun(t *testing.T) {
 					if !slices.Contains(c.want, path.Base(entry.Name())) {
 						t.Errorf("unexpected %s", entry.Name())
 					}
-					if stat, err := entry.Info(); err != nil {
+					if !entry.Type().IsRegular() {
-						t.Errorf("cant read info of %s: %v", entry.Name(), err)
+						t.Errorf("non-regular file %s in out: %v", entry.Name(), entry.Type())
-					} else if !stat.Mode().IsRegular() {
-						t.Errorf("non-regular file %s in out: %v", entry.Name(), stat.Mode())
-					}
-				}
-			}
-
-			if entries, err := os.ReadDir(outd); err != nil {
-				t.Error("failed to list outdir: %w", err)
-			} else {
-				for _, entry := range entries {
-					if !slices.Contains(c.want, path.Base(entry.Name())) {
-						t.Errorf("unexpected %s", entry.Name())
 					}
 				}
 			}