paths safeguard

.gitignore

@@ -1,2 +1,3 @@
 *.jpg
-*.png
+*.png
+output/

blend.go

@@ -8,6 +8,7 @@ import (
 	"log"
 	"math"
 	"os"
+	"path"
 )
 
 // convert RGBA pixel to grayscale. BT.709 luminosity formula
@@ -115,7 +116,7 @@ func blendColor(color1 color.Color, color2 color.Color) color.Color {
 
 // encode the image
 func encodeImage(imgData *image.RGBA) {
-	outputFile := fmt.Sprintf("%s/%s", ConfigRegister.OutputDir, "output.jpg")
+	outputFile := fmt.Sprintf("%s/%s", path.Clean(ConfigRegister.OutputDir), "output.jpg")
 	out, _ := os.Create(outputFile)
 	defer out.Close()
 	log.Println("Encoding the new image...")

config.go

@@ -4,6 +4,7 @@ import (
 	"encoding/json"
 	"flag"
 	"fmt"
+	"log"
 	"os"
 	"strconv"
 	"strings"
@@ -48,13 +49,35 @@ func (c *Config) SetOutputDimensions() {
 	c.OutputHeight = height
 }
 
+func (c *Config) CheckPaths() {
+	_, err := os.Stat(c.OutputDir)
+
+	if err != nil {
+		log.Fatal("Output dir does not exist :", c.OutputDir)
+	}
+
+	_, err = os.Stat(c.InputDir)
+
+	if err != nil {
+		log.Fatal("Input dir does not exist :", c.InputDir)
+	}
+
+	if (c.BaseImage != "") {
+		_, err = os.Stat(c.BaseImage)
+
+		if err != nil {
+			log.Fatal("Base image does not exist :", c.BaseImage)
+		}
+	}
+}
+
 func initConfigRegister() {
 	// default seed for the RNG
 	seed := time.Now().UnixNano()
 
 	// command line arguments
 	flag.StringVar(&ConfigRegister.Method, "blending", "darken", "Blending methods : darken, lighten, average, fuckyfun")
-	flag.StringVar(&ConfigRegister.OutputDir, "output", "./", "Output directory")
+	flag.StringVar(&ConfigRegister.OutputDir, "output", "./output", "Output directory")
 	flag.StringVar(&ConfigRegister.InputDir, "input", "/home/gator/Photos", "Input directory. Where to look the images from")
 	flag.StringVar(&ConfigRegister.BaseImage, "base-img", "", "Path to the base image to work with. Random image if not set")
 	flag.StringVar(&ConfigRegister.Dimensions, "dimensions", "1280x1024", "Out image dimensions. <width>x<height>")
@@ -66,6 +89,8 @@ func initConfigRegister() {
 
 	flag.Parse()
 
+	ConfigRegister.CheckPaths()
+
 	// set output's width and height
 	ConfigRegister.SetOutputDimensions()
 }