Adds support for listing directories as well as getting file contents

local/local.go

@@ -4,18 +4,57 @@ import (
 	"fmt"
 	"io/ioutil"
 	"os"
+	"strings"
 )
 
 func Open(address string) (string, error) {
+	if !pathExists(address) {
+		return "", fmt.Errorf("Invalid system path: %s", address)
+	}
+
 	file, err := os.Open(address)
 	if err != nil {
 		return "", fmt.Errorf("Unable to open file: %s", address)
 	}
 	defer file.Close()
 
+
+	if pathIsDir(address) {
+		fileList, err := file.Readdirnames(0)
+		if err != nil {
+			return "", fmt.Errorf("Unable to read from directory: %s", address)
+		}
+		var out strings.Builder
+		out.WriteString(fmt.Sprintf("Current directory: %s\n\n", address))
+		for _, obj := range fileList {
+			out.WriteString(obj)
+			out.WriteString("\n")
+		}
+		return out.String(), nil
+	}
+
 	bytes, err := ioutil.ReadAll(file)
 	if err != nil {
 		return "", fmt.Errorf("Unable to read file: %s", address)
 	}
 	return string(bytes), nil
 }
+
+
+func pathExists(p string) bool {
+	exists := true
+
+  if _, err := os.Stat(p); os.IsNotExist(err) {
+    exists = false
+  }
+
+  return exists
+}
+
+func pathIsDir(p string) bool {
+  info, err := os.Stat(p)
+	if err != nil {
+		return false
+  }
+	return info.IsDir()
+}

url.go

@@ -130,3 +130,4 @@ func MakeUrl(u string) (Url, error) {
 
 	return out, nil
 }
+