Nmap error handling

nmap.go

@@ -4,7 +4,6 @@ package nmap
 import (
 	"bytes"
 	"context"
-	"errors"
 	"fmt"
 	"os/exec"
 	"strings"
@@ -83,11 +82,14 @@ func (s *Scanner) Run() (*Run, error) {
 		return nil, ErrScanTimeout
 	case <-done:
 		// Scan finished before timeout.
+		var nmapErrors []NmapErrors
 		if stderr.Len() > 0 {
-			return nil, errors.New(strings.Trim(stderr.String(), ".\n"))
+			for _, v := range RemoveDuplicatesFromSlice(strings.Split(strings.Trim(stderr.String(), "\n"), "\n")) {
+				nmapErrors = append(nmapErrors, NmapErrors{Error: v})
+			}
 		}
 
-		result, err := Parse(stdout.Bytes())
+		result, err := Parse(stdout.Bytes(), nmapErrors)
 		if err != nil {
 			return nil, fmt.Errorf("unable to parse nmap output: %v", err)
 		}

utils.go

@@ -0,0 +1,18 @@
+package nmap
+
+// https://siongui.github.io/2018/04/14/go-remove-duplicates-from-slice-or-array/
+func RemoveDuplicatesFromSlice(s []string) []string {
+	m := make(map[string]bool)
+	for _, item := range s {
+		if _, ok := m[item]; ok {
+		} else {
+			m[item] = true
+		}
+	}
+
+	var result []string
+	for item := range m {
+		result = append(result, item)
+	}
+	return result
+}

xml.go

@@ -32,7 +32,12 @@ type Run struct {
 	TaskProgress     []TaskProgress `xml:"taskprogress" json:"task_progress"`
 	TaskEnd          []Task         `xml:"taskend" json:"task_end"`
 
-	rawXML []byte
+	NmapErrors []NmapError
+	rawXML     []byte
+}
+
+type NmapError struct {
+	Error string
 }
 
 // ToFile writes a Run as XML into the specified file path.
@@ -418,9 +423,10 @@ func (t *Timestamp) UnmarshalXMLAttr(attr xml.Attr) (err error) {
 
 // Parse takes a byte array of nmap xml data and unmarshals it into a
 // Run struct.
-func Parse(content []byte) (*Run, error) {
+func Parse(content []byte, nmapErrors []NmapError) (*Run, error) {
 	r := &Run{
-		rawXML: content,
+		rawXML:     content,
+		NmapErrors: nmapErrors,
 	}
 
 	err := xml.Unmarshal(content, r)