log to file

files.go

@@ -1,7 +1,7 @@
 package main
 
 import (
-	"fmt"
+	"log"
 	"math/rand"
 	"os"
 	"regexp"
@@ -20,13 +20,13 @@ func getRandomFile(dir string) (path string, filename string, error error) {
 		randomImg = files[randomIndex]
 		//re-roll if you get a directory
 		if files[randomIndex].IsDir() {
-			fmt.Printf("%v is a directory. Trying again... \n", randomImg.Name())
+			log.Printf("%v is a directory. Trying again... \n", randomImg.Name())
 			continue
 		}
 		//re-roll if not a recognised image type
 		isImage, _ := regexp.Match(".jpg$|.jpeg$|.png$|.bmp$|.webp$", []byte(randomImg.Name()))
 		if !isImage {
-			fmt.Printf("%v is not a recognised image format\n", randomImg.Name())
+			log.Printf("%v is not a recognised image format\n", randomImg.Name())
 			continue
 		}
 		//TODO: re-roll if you get the same image

image.go

@@ -1,7 +1,6 @@
 package main
 
 import (
-	"fmt"
 	"image"
 	"log"
 	"os"
@@ -38,7 +37,7 @@ func hexToHSL(string) [3]int {
 func pickRandomImage(dir string) (string, error) {
 
 	dir = config.ImagesDir + dir
-	fmt.Printf("getting random file from %v\n", dir)
+	log.Printf("getting random file from %v\n", dir)
 	randomImg, filename, _ := getRandomFile(dir)
 	filenameNoExt := strings.TrimSuffix(filename, filepath.Ext(filename))
 
@@ -51,7 +50,7 @@ func pickRandomImage(dir string) (string, error) {
 	if !fileExists {
 		img, err := loadImage(randomImg)
 		if err != nil {
-			fmt.Printf("failed to load image %v", randomImg)
+			log.Printf("failed to load image %v", randomImg)
 			return "", err
 		}
 		dst := processImage(img, config)

main.go

@@ -1,8 +1,7 @@
 package main
 
 import (
-	"fmt"
-	// "log"
+	"log"
 	"os"
 	"sync"
 )
@@ -12,7 +11,15 @@ var config Config
 func main() {
 
 	config.load()
-	fmt.Printf("%+v\n", config)
+
+	//TODO: only log to file if flagged
+	logfile, err := openLogfile()
+	if err != nil {
+		log.Printf("error opening logfile %v: %v", config.Cache, err)
+	}
+	log.SetOutput(logfile)
+	log.SetFlags(log.LstdFlags | log.Lshortfile | log.Lmicroseconds)
+	log.Println("Welcome to GoPaper!")
 
 	var waitGroup sync.WaitGroup
 	waitGroup.Add(1)
@@ -25,9 +32,18 @@ func main() {
 	if len(args) > 0 {
 		dir = args[0]
 	} else {
-		dir = ""
+		dir = config.Default
 	}
 	slideshowDir <- dir
 
 	waitGroup.Wait()
 }
+
+func openLogfile() (*os.File, error) {
+	//TODO: log rotation
+	f, err := os.OpenFile(config.Cache+"/logfile", os.O_RDWR|os.O_CREATE|os.O_APPEND, 0666)
+	if err != nil {
+		return nil, err
+	}
+	return f, nil
+}