cli has dry mode and install script

cmd/pttodo-cli/cli.go

@@ -7,6 +7,7 @@ import (
 	"io"
 	"io/ioutil"
 	"local/pt-todo-server/pttodo"
+	"log"
 	"os"
 	"os/exec"
 	"path"
@@ -28,16 +29,17 @@ func _main() error {
 	}
 	filepath := flag.String("f", defaultFilepath, "($PTTODO_FILE) path to yaml file")
 	e := flag.Bool("e", false, "edit file")
+	dry := flag.Bool("dry", false, "dry run")
 	flag.Parse()
 	if *e {
-		if err := edit(*filepath); err != nil {
+		if err := edit(*dry, *filepath); err != nil {
 			return err
 		}
 	}
-	return dump(os.Stdout, *filepath)
+	return dump(*dry, os.Stdout, *filepath)
 }
 
-func edit(filepath string) error {
+func edit(dry bool, filepath string) error {
 	var tempFile string
 	cp := func() error {
 		f, err := ioutil.TempFile(os.TempDir(), path.Base(filepath))
@@ -90,15 +92,19 @@ func edit(filepath string) error {
 		return nil
 	}
 	verify := func() error {
-		return dump(io.Discard, tempFile)
+		return dump(true, io.Discard, tempFile)
 	}
 	save := func() error {
+		if dry {
+			log.Printf("would've saved %s as %s", tempFile, filepath)
+			return nil
+		}
 		return os.Rename(tempFile, filepath)
 	}
 
 	for _, foo := range []func() error{cp, vi, verify, save} {
 		if err := foo(); err != nil {
-			if tempFile != "" {
+			if tempFile != "" && !dry {
 				os.Remove(tempFile)
 			}
 			return err
@@ -108,7 +114,7 @@ func edit(filepath string) error {
 	return nil
 }
 
-func dump(writer io.Writer, filepath string) error {
+func dump(dry bool, writer io.Writer, filepath string) error {
 	var reader io.Reader
 	if filepath == "-" {
 		reader = os.Stdin
@@ -136,5 +142,10 @@ func dump(writer io.Writer, filepath string) error {
 		return err
 	}
 	fmt.Fprintf(writer, "%s\n", b2)
-	return nil
+
+	if dry {
+		return nil
+	}
+
+	return os.WriteFile(filepath, b2, os.ModePerm)
 }