Added XML escaper/unescaper (#22)

README.md

@@ -34,6 +34,8 @@ Available encoders:
   urlencodeall      - URL encode all characters
   utf16             - UTF-16 encoder (Little Endian)
   utf16be           - UTF-16 encoder (Big Endian)
+  xmlescape         - XML escape
+  xmlunescape       - XML unescape
 ```
 
 To urlencode, base64encode and hex encode a string:
@@ -58,6 +60,8 @@ $ echo 'what%ever'|pencode urlencode b64encode hexencode
 - URL decoder
 - UTF16 encoder (Little Endian)
 - UTF16 encoder (Big Endian)
+- XML escape encoder (reserved characters)
+- XML escape decoder
 
 
 ### Shell completion

pkg/pencode/encoders.go

@@ -19,6 +19,8 @@ var availableEncoders = map[string]Encoder{
 	"urlencodeall":     URLEncoderAll{},
 	"utf16":            UTF16LEEncode{},
 	"utf16be":          UTF16BEEncode{},
+	"xmlescape":        XMLEscaper{},
+	"xmlunescape":      XMLUnescaper{},
 }
 
 type Chain struct {

pkg/pencode/xmldecode.go

@@ -0,0 +1,24 @@
+package pencode
+
+import "encoding/xml"
+
+type XMLUnescaper struct{}
+
+type XMLInput struct {
+	Input string `xml:"input"`
+}
+
+func (u XMLUnescaper) Encode(input []byte) ([]byte, error) {
+	inputXML := `<xml><input>` + string(input) + `</input></xml>`
+
+	var out XMLInput
+	if err := xml.Unmarshal([]byte(inputXML), &out); err != nil {
+		return []byte{}, err
+	}
+
+	return []byte(out.Input), nil
+}
+
+func (u XMLUnescaper) HelpText() string {
+	return "XML unescape"
+}

pkg/pencode/xmlencode.go

@@ -0,0 +1,23 @@
+package pencode
+
+import (
+	"bytes"
+	"encoding/xml"
+)
+
+type XMLEscaper struct{}
+
+func (u XMLEscaper) Encode(input []byte) ([]byte, error) {
+	buf := &bytes.Buffer{}
+
+	if err := xml.EscapeText(buf, input); err != nil {
+		return []byte{}, err
+	}
+
+	output := buf.Bytes()
+	return output, nil
+}
+
+func (u XMLEscaper) HelpText() string {
+	return "XML escape"
+}