Go library for detecting and fixing Cyrillic text encoding issues (mojibake).

Handles common encoding problems with Russian and other Cyrillic text:

go get github.com/drgolem/cyrillic-encoding

package main

import (
	"fmt"
	cyrillic "github.com/drgolem/cyrillic-encoding"
)

func main() {
	// Fix CP1251 bytes that were decoded as ISO-8859-1
	fixed, ok := cyrillic.ReencodeISO8859AsCP1251(garbledText)
	if ok {
		fmt.Println(fixed) // correct Cyrillic text
	}

	// Fix UTF-8 text that was misread as CP1251 (double-encoded mojibake)
	fixed = cyrillic.DecodeMojibakeFromCP1251(mojibakeText)

	// Fix UTF-8 text that was misread as ISO-8859-1
	fixed = cyrillic.DecodeMojibakeFromISO8859(mojibakeText)

	// Check if text is pure printable ASCII (no high bytes)
	if cyrillic.IsASCIIPrintable(text) {
		fmt.Println("text is ASCII-only")
	}

	// Count Cyrillic characters (weighted: lowercase=2, uppercase=1)
	score := cyrillic.CountCyrillic(text)
}

• ReencodeISO8859AsCP1251(str string) (string, bool) - Fix CP1251 bytes decoded as ISO-8859-1. Returns the corrected string and true on success.
• DecodeMojibakeFromISO8859(mojibake string) string - Fix UTF-8 bytes misread as ISO-8859-1.
• DecodeMojibakeFromCP1251(mojibake string) string - Fix UTF-8 bytes misread as CP1251. Uses Cyrillic character heuristics to validate.

• IsASCIIPrintable(str string) bool - Check if all characters are printable ASCII (bytes 32-127).
• CountCyrillic(s string) int - Count Cyrillic characters with weighted scoring (lowercase=2x).
• CP1251ToByte(r rune) byte - Convert a Unicode rune to its CP1251 byte value.

This package has zero external dependencies - only Go standard library.

MIT