feat: add support for urls

cmd/cmd.go

@@ -2,6 +2,7 @@ package cmd
 
 import (
 	"fmt"
+	"image"
 	"os"
 
 	"github.com/spf13/cobra"
@@ -22,12 +23,22 @@ var cmd = &cobra.Command{
 
 	Run: func(cmd *cobra.Command, args []string) {
 		path := args[0]
-		if !PathExists(path) {
+		url := img.IsUrl(path)
+
+		if !url && !PathExists(path) {
 			cobra.CheckErr(fmt.Errorf("could not find file: %s", path))
 		}
 
-		image, err := img.Decode(path)
-		cobra.CheckErr(err)
+		image := image.Image(nil)
+		err := error(nil)
+		if !url {
+			image, err = img.Decode(path)
+		} else {
+			image, err = img.DecodeFromUrl(path)
+		}
+		if err != nil {
+			cobra.CheckErr(err)
+		}
 
 		columns, _ := cmd.Flags().GetInt("columns")
 		rows, _ := cmd.Flags().GetInt("rows")

img/img.go

@@ -5,6 +5,7 @@ import (
 	_ "image/gif"
 	_ "image/jpeg"
 	_ "image/png"
+	"net/http"
 	"os"
 
 	"github.com/nfnt/resize"
@@ -49,3 +50,22 @@ func Resize(image image.Image, width, height int) image.Image {
 
 	return image
 }
+
+func DecodeFromUrl(url string) (image.Image, error) {
+	resp, err := http.Get(url)
+	if err != nil {
+		return nil, err
+	}
+	defer resp.Body.Close()
+
+	img, _, err := image.Decode(resp.Body)
+	if err != nil {
+		return nil, err
+	}
+
+	return img, nil
+}
+
+func IsUrl(path string) bool {
+	return path[:4] == "http"
+}