oem

README

go-oem

A Go library for encoding and decoding strings using OEM (Original Equipment Manufacturer) code pages, including DOS, Windows, IBM/EBCDIC, and CJK encodings.

Installation

go get github.com/oiweiwei/go-oem

Usage

Top-level encode/decode (uses CP437 by default)

import "github.com/oiweiwei/go-oem"

b, err := oem.Encode("Hello")
s, err := oem.Decode(b)

Change the default encoding

oem.WithDefaultEncoding(oem.CP850_DOSLatin1())

Use a specific encoding directly

enc := oem.CP866_DOSCyrillicRussian()
b, err := enc.Encode("Привет")
s, err := enc.Decode(b)

Context-scoped encoding

ctx := oem.WithContext(context.Background(), oem.CP1251())
enc := oem.FromContext(ctx)

Supported encodings

Constant	Description
ASCII	7-bit ASCII
CP437_DOSLatinUS	DOS Latin US (default)
CP500_IBMInternational	IBM International (EBCDIC)
CP737_DOSGreek	DOS Greek
CP775_DOSBaltRim	DOS Baltic Rim
CP850_DOSLatin1	DOS Latin 1
CP852_DOSLatin2	DOS Latin 2
CP855_DOSCyrillic	DOS Cyrillic
CP857_DOSTurkish	DOS Turkish
CP860_DOSPortuguese	DOS Portuguese
CP861_DOSIcelandic	DOS Icelandic
CP862_DOSHebrew	DOS Hebrew
CP863_DOSCanadaF	DOS Canadian French
CP864_DOSArabic	DOS Arabic
CP865_DOSNordic	DOS Nordic
CP866_DOSCyrillicRussian	DOS Cyrillic Russian
CP869_DOSGreek2	DOS Greek 2
CP874_DOSThai	DOS Thai
CP875_IBMGreek	IBM Greek
CP932	Japanese Shift-JIS
CP936	Simplified Chinese GBK
CP949	Korean EUC-KR
CP950	Traditional Chinese Big5
CP1026_IBMLatin5Turkish	IBM Latin-5 Turkish
CP1250	Windows Central European
CP1251	Windows Cyrillic
CP1252	Windows Western European
EBCDIC037	EBCDIC 037
EBCDIC273	EBCDIC 273
EBCDIC500	EBCDIC 500
EBCDIC1140	EBCDIC 1140
EBCDIC1141	EBCDIC 1141
EBCDIC1148	EBCDIC 1148

Each constant is a factory function -- call it to get an Encoding instance.

License

See LICENSE.

Documentation

Overview

Package oem provides encoders and decoders for OEM (Original Equipment Manufacturer) code pages, including DOS, Windows, IBM EBCDIC, and CJK encodings.

Each encoding is exposed as a package-level variable of type func() Encoding. Call the variable to obtain an Encoding instance:

enc := oem.CP850_DOSLatin1()
b, err := enc.Encode("cafe")

The package also exposes top-level Encode and Decode helpers that operate on the default encoding (CP437 unless overridden with WithDefaultEncoding).

Index

• Variables
• func Decode(b []byte) (string, error)
• func Encode(s string) ([]byte, error)
• func WithContext(ctx context.Context, e Encoding) context.Context
• func WithDefaultEncoding(e Encoding)
• type Encoding
  • func DefaultEncoding() Encoding
  • func FromContext(ctx context.Context) Encoding

Variables

var (
	// ASCII is 7-bit ASCII. Non-ASCII runes are replaced with 0x1A on encode.
	ASCII = func() Encoding { return enc.ASCII{} }
	// CP437_DOSLatinUS is IBM/DOS Code Page 437 (DOS Latin US). This is the
	// default encoding used by the top-level Encode and Decode functions.
	CP437_DOSLatinUS = func() Encoding { return enc.NewCharmap(charmap.CodePage437) }
	// CP500_IBMInternational is IBM Code Page 500, an EBCDIC encoding used for
	// international IBM mainframe applications.
	CP500_IBMInternational = func() Encoding { return enc.NewEBCDIC(ebcdic.EBCDIC500) }
	// CP737_DOSGreek is DOS Code Page 737 (DOS Greek).
	CP737_DOSGreek = func() Encoding { return enc.NewCharmap2(enc.CP737_DOSGreek) }
	// CP775_DOSBaltRim is DOS Code Page 775 (DOS Baltic Rim).
	CP775_DOSBaltRim = func() Encoding { return enc.NewCharmap2(enc.CP775_DOSBaltRim) }
	// CP850_DOSLatin1 is DOS Code Page 850 (DOS Latin 1 / Western European).
	CP850_DOSLatin1 = func() Encoding { return enc.NewCharmap(charmap.CodePage850) }
	// CP852_DOSLatin2 is DOS Code Page 852 (DOS Latin 2 / Central European).
	CP852_DOSLatin2 = func() Encoding { return enc.NewCharmap(charmap.CodePage852) }
	// CP855_DOSCyrillic is DOS Code Page 855 (DOS Cyrillic).
	CP855_DOSCyrillic = func() Encoding { return enc.NewCharmap(charmap.CodePage855) }
	// CP857_DOSTurkish is DOS Code Page 857 (DOS Turkish).
	CP857_DOSTurkish = func() Encoding { return enc.NewCharmap2(enc.CP857_DOSTurkish) }
	// CP860_DOSPortuguese is DOS Code Page 860 (DOS Portuguese).
	CP860_DOSPortuguese = func() Encoding { return enc.NewCharmap(charmap.CodePage860) }
	// CP861_DOSIcelandic is DOS Code Page 861 (DOS Icelandic).
	CP861_DOSIcelandic = func() Encoding { return enc.NewCharmap2(enc.CP861_DOSIcelandic) }
	// CP862_DOSHebrew is DOS Code Page 862 (DOS Hebrew).
	CP862_DOSHebrew = func() Encoding { return enc.NewCharmap(charmap.CodePage862) }
	// CP863_DOSCanadaF is DOS Code Page 863 (DOS Canadian French).
	CP863_DOSCanadaF = func() Encoding { return enc.NewCharmap(charmap.CodePage863) }
	// CP864_DOSArabic is DOS Code Page 864 (DOS Arabic).
	CP864_DOSArabic = func() Encoding { return enc.NewCharmap2(enc.CP864_DOSArabic) }
	// CP865_DOSNordic is DOS Code Page 865 (DOS Nordic).
	CP865_DOSNordic = func() Encoding { return enc.NewCharmap(charmap.CodePage863) }
	// CP866_DOSCyrillicRussian is DOS Code Page 866 (DOS Cyrillic Russian).
	CP866_DOSCyrillicRussian = func() Encoding { return enc.NewCharmap(charmap.CodePage866) }
	// CP869_DOSGreek2 is DOS Code Page 869 (DOS Greek 2).
	CP869_DOSGreek2 = func() Encoding { return enc.NewCharmap2(enc.CP869_DOSGreek2) }
	// CP874_DOSThai is DOS/Windows Code Page 874 (Thai).
	CP874_DOSThai = func() Encoding { return enc.NewCharmap2(enc.CP874) }
	// CP875_IBMGreek is IBM Code Page 875 (IBM Greek, EBCDIC-based).
	CP875_IBMGreek = func() Encoding { return enc.NewCharmap2(enc.CP875_IBMGreek) }
	// CP932 is Windows Code Page 932 (Japanese Shift-JIS).
	CP932 = func() Encoding { return enc.NewCharmap(japanese.ShiftJIS) }
	// CP936 is Windows Code Page 936 (Simplified Chinese GBK).
	CP936 = func() Encoding { return enc.NewCharmap(simplifiedchinese.GBK) }
	// CP949 is Windows Code Page 949 (Korean EUC-KR).
	CP949 = func() Encoding { return enc.NewCharmap(korean.EUCKR) }
	// CP950 is Windows Code Page 950 (Traditional Chinese Big5).
	CP950 = func() Encoding { return enc.NewCharmap(traditionalchinese.Big5) }
	// CP1026_IBMLatin5Turkish is IBM Code Page 1026 (IBM Latin-5 Turkish, EBCDIC-based).
	CP1026_IBMLatin5Turkish = func() Encoding { return enc.NewCharmap2(enc.CP1026_IBMLatin5Turkish) }
	// CP1250 is Windows Code Page 1250 (Windows Central European).
	CP1250 = func() Encoding { return enc.NewCharmap(charmap.Windows1250) }
	// CP1251 is Windows Code Page 1251 (Windows Cyrillic).
	CP1251 = func() Encoding { return enc.NewCharmap(charmap.Windows1251) }
	// CP1252 is Windows Code Page 1252 (Windows Western European / Latin 1).
	CP1252 = func() Encoding { return enc.NewCharmap(charmap.Windows1252) }
	// EBCDIC037 is IBM EBCDIC Code Page 037 (US/Canada).
	EBCDIC037 = func() Encoding { return enc.NewEBCDIC(ebcdic.EBCDIC037) }
	// EBCDIC1140 is IBM EBCDIC Code Page 1140 (US/Canada with Euro sign).
	EBCDIC1140 = func() Encoding { return enc.NewEBCDIC(ebcdic.EBCDIC1140) }
	// EBCDIC1141 is IBM EBCDIC Code Page 1141 (Germany/Austria with Euro sign).
	EBCDIC1141 = func() Encoding { return enc.NewEBCDIC(ebcdic.EBCDIC1141) }
	// EBCDIC1148 is IBM EBCDIC Code Page 1148 (International with Euro sign).
	EBCDIC1148 = func() Encoding { return enc.NewEBCDIC(ebcdic.EBCDIC1148) }
	// EBCDIC273 is IBM EBCDIC Code Page 273 (Germany/Austria).
	EBCDIC273 = func() Encoding { return enc.NewEBCDIC(ebcdic.EBCDIC273) }
	// EBCDIC500 is IBM EBCDIC Code Page 500 (International).
	EBCDIC500 = func() Encoding { return enc.NewEBCDIC(ebcdic.EBCDIC500) }
)

Predefined OEM encoding factories. Each variable is a function that returns a new Encoding instance for the corresponding code page.

Functions

func Decode

func Decode(b []byte) (string, error)

Decode decodes b using the package-level default encoding.

func Encode

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

Encode encodes s using the package-level default encoding.

func WithContext

func WithContext(ctx context.Context, e Encoding) context.Context

WithContext returns a copy of ctx carrying the given encoding. Use FromContext to retrieve it in downstream code.

func WithDefaultEncoding

func WithDefaultEncoding(e Encoding)

WithDefaultEncoding sets the package-level default encoding used by the top-level Encode and Decode functions. It is safe for concurrent use.

Types

type Encoding

type Encoding interface {
	// Encode converts a UTF-8 string to the code page byte representation.
	// Characters that have no mapping in the target encoding are replaced
	// with the ASCII SUB character (0x1A).
	Encode(string) ([]byte, error)
	// Decode converts a code page byte slice to a UTF-8 string.
	// Bytes with no defined mapping are replaced with the Unicode replacement
	// character (U+FFFD).
	Decode([]byte) (string, error)
}

Encoding is the interface implemented by all OEM encodings. It provides bidirectional conversion between Go strings (UTF-8) and the encoded byte representation of a specific code page.

func DefaultEncoding

func DefaultEncoding() Encoding

DefaultEncoding returns the current package-level default encoding. It is safe for concurrent use. The default is CP437_DOSLatinUS unless changed with WithDefaultEncoding.

func FromContext

func FromContext(ctx context.Context) Encoding

FromContext returns the Encoding stored in ctx by WithContext. If no encoding is present, the package-level default encoding is returned.