add log file writer

2 files changed, 25 insertions, 2 deletions

diff --git a/README.md b/README.md
index 77b23aa..b66a2be 100644
--- a/README.md
+++ b/README.md
@@ -19,6 +19,7 @@ ASS字幕字体子集化 MKV批量提取/生成
   apt install mkvtoolnix #Debian/Ubuntu
   apk add mkvtoolnix #Alpine
   ```
+
 #### 关于Windows用户
 
 - 从 [这里](https://www.python.org/downloads) 下载并安装Python
@@ -38,6 +39,15 @@ ASS字幕字体子集化 MKV批量提取/生成
 
 ## mkvtool 功能及使用示例
 
+- 标准工作流
+  ```shell
+  mkvtool -s bangumi 
+  #从${bangumi}文件夹抽取所有mkv文件的字幕和字体,
+  #遇到ass字幕就自动进行子集化,
+  #输出替换字幕和字体后的新mkv文件.
+  #-data参数默认值为"${workdir}/data",指定提取mkv的输出文件夹.
+  #-dist参数默认值为"${workdir}/dist",指定重组后mkv的输出文件夹.
+  ```
 - 从单个(或文件夹的)mkv文件里抽取字幕和字体*并创建子集化后的版本(可选)*
   ```shell
   mkvtool -d -f file.mkv #单个文件
@@ -129,6 +139,7 @@ ASS字幕字体子集化 MKV批量提取/生成
 
 ### 一些碎碎念
 
+- "-log"参数:输出终端输出到指定文件,空为不输出,默认为空.
 - "-m","-c"模式下的"-sl","-st"参数:
    ```
    -sl:字幕语言.格式为语言缩写如"chi","jpn","eng"等,默认值为"chi".
diff --git a/mkvtool/main.go b/mkvtool/main.go
index ce55269..285b0f1 100644
--- a/mkvtool/main.go
+++ b/mkvtool/main.go
@@ -4,6 +4,7 @@ import (
 	"flag"
 	"fmt"
 	"github.com/KurenaiRyu/MkvAutoSubset/mkvlib"
+	"io"
 	"log"
 	"os"
 	"path"
@@ -12,7 +13,7 @@ import (
 )
 
 const appName = "MKV Tool"
-const appVer = "v3.1.4"
+const appVer = "v3.1.5"
 const tTitle = appName + " " + appVer
 
 var processer = mkvlib.GetInstance()
@@ -46,6 +47,7 @@ func main() {
 	ans := false
 	sl, st := "", ""
 	af, ao := "", ""
+	flog := ""
 	asses := new(arrayArg)
 	flag.StringVar(&s, "s", "", "Source folder.")
 	flag.StringVar(&f, "f", "", "MKV file. (join single mode)")
@@ -63,13 +65,23 @@ func main() {
 	flag.BoolVar(&ans, "ans", false, `ASS output not to the new "subsetted" folder. (ass mode only)`)
 	flag.StringVar(&data, "data", "data", "Subtitles & Fonts folder (dump & make mode only)")
 	flag.StringVar(&dist, "dist", "dist", "Results output folder (make mode only)")
+	flag.StringVar(&flog, "log", "", "Log file path")
 
 	flag.BoolVar(&v, "v", false, "Show app info.")
 	flag.Parse()
 
+	if flog != "" {
+		lf, err := os.OpenFile(flog, os.O_CREATE|os.O_RDWR, os.ModePerm)
+		if err != nil {
+			log.Printf(`Failed to create log file: "%s"`, flog)
+		}
+		mw := io.MultiWriter(os.Stdout, lf)
+		log.SetOutput(mw)
+	}
+
 	ec := 0
 	if v {
-		fmt.Println(appFN + " (powered by " + mkvlib.LibFName + ")")
+		log.Printf("%s (powered by %s)", appFN, mkvlib.LibFName)
 		return
 	}