quotedprintable

README

quotedprintable

Introduction

Package quotedprintable implements quoted-printable and message header encoding as specified by RFC 2045 and RFC 2047.

It is similar to the package currently being developed in the standard library: https://codereview.appspot.com/132680044/

It requires Go 1.3 or newer.

Some links:

• Post on golang-dev
• issue on the bug traker
• the former code review

Documentation

https://godoc.org/gopkg.in/alexcesaro/quotedprintable.v2

Documentation

Overview

Package quotedprintable implements quoted-printable and message header encoding as specified by RFC 2045 and RFC 2047.

Index

• func Decode(dst, src []byte) (n int, err error)
• func DecodeHeader(header string) (text, charset string, err error)
• func DecodeString(s string) ([]byte, error)
• func Encode(dst, src []byte) int
• func EncodeToString(src []byte) string
• func MaxDecodedLen(n int) int
• func MaxEncodedLen(n int) int
• func NeedsEncoding(s string) bool
• func NewDecoder(r io.Reader) io.Reader
• func NewEncoder(w io.Writer) io.Writer
• type Encoding
  • func (enc Encoding) NewHeaderEncoder(charset string) *HeaderEncoder
• type HeaderEncoder
  • func (e *HeaderEncoder) Encode(s string) string

Examples

• DecodeHeader
• DecodeString
• EncodeToString
• NewEncoder

Functions

func Decode

func Decode(dst, src []byte) (n int, err error)

Decode decodes src into at most MaxDecodedLen(len(src)) bytes to dst, returning the actual number of bytes written to dst.

func DecodeHeader

func DecodeHeader(header string) (text, charset string, err error)

DecodeHeader decodes a MIME header by decoding all encoded-words of the header. The returned text is encoded in the returned charset. Text is not necessarily encoded in UTF-8. Returned charset is always upper case. This function does not support decoding headers with multiple encoded-words using different charsets.

Example

// text is not encoded in UTF-8 but in ISO-8859-1
text, charset, err := DecodeHeader("=?ISO-8859-1?Q?Caf=C3?=")
if err != nil {
	panic(err)
}
fmt.Printf("Text: %q, charset: %q", text, charset)

Output:

Text: "Caf\xc3", charset: "ISO-8859-1"

func DecodeString

func DecodeString(s string) ([]byte, error)

DecodeString returns the bytes represented by the quoted-printable string s.

Example

str := "=C2=A1Hola, se=C3=B1or!"
data, err := DecodeString(str)
if err != nil {
	fmt.Println("error:", err)
	return
}
fmt.Printf("%s\n", data)

Output:

¡Hola, señor!

func Encode

func Encode(dst, src []byte) int

Encode encodes src into at most MaxEncodedLen(len(src)) bytes to dst, returning the actual number of bytes written to dst.

func EncodeToString

func EncodeToString(src []byte) string

EncodeToString returns the quoted-printable encoding of src.

Example

data := []byte("¡Hola, señor!")
str := EncodeToString(data)
fmt.Println(str)

Output:

=C2=A1Hola, se=C3=B1or!

func MaxDecodedLen

func MaxDecodedLen(n int) int

MaxDecodedLen returns the maximum length of a decoding of n source bytes.

func MaxEncodedLen

func MaxEncodedLen(n int) int

MaxEncodedLen returns the maximum length of an encoding of n source bytes.

func NeedsEncoding

func NeedsEncoding(s string) bool

NeedsEncoding returns whether the given header content needs to be encoded into an encoded-words.

func NewDecoder

func NewDecoder(r io.Reader) io.Reader

NewDecoder returns a new quoted-printable stream decoder.

func NewEncoder

func NewEncoder(w io.Writer) io.Writer

NewEncoder returns a new quoted-printable stream encoder. Data written to the returned writer will be encoded and then written to w.

Example

input := []byte("Café")
encoder := NewEncoder(os.Stdout)
encoder.Write(input)

Output:

Caf=C3=A9

Types

type Encoding

type Encoding string

Encoding represents the encoding used in encoded-words. It must be one of the two encodings defined in RFC 2047 ("B" or "Q" encoding).

const (
	// Q represents the Q-encoding defined in RFC 2047.
	Q Encoding = "Q"
	// B represents the Base64 encoding defined in RFC 2045.
	B Encoding = "B"
)

func (Encoding) NewHeaderEncoder

func (enc Encoding) NewHeaderEncoder(charset string) *HeaderEncoder

NewHeaderEncoder returns a new HeaderEncoder to encode strings in the specified charset.

type HeaderEncoder

type HeaderEncoder struct {
	// contains filtered or unexported fields
}

A HeaderEncoder is an RFC 2047 encoded-word encoder.

func (*HeaderEncoder) Encode

func (e *HeaderEncoder) Encode(s string) string

Encode encodes a string to be used as a MIME header value.