Golangでincovを使うサンプル

go-iconv

package main

/*
#include <stdlib.h>
#include <iconv.h>
#cgo LDFLAGS: -liconv
*/
import "C"
import (
    "unsafe"
)

type Iconv struct {
	pointer C.iconv_t
}

func Open(tocode, fromcode string) (*Iconv, error) {
	cs_tocode := C.CString(tocode)
	defer C.free(unsafe.Pointer(cs_tocode))
	cs_fromcode := C.CString(fromcode)
	defer C.free(unsafe.Pointer(cs_fromcode))

	iconv, err := C.iconv_open(cs_tocode, cs_fromcode)
	if err != nil {
		return nil, err
	}
	return &Iconv{iconv}, nil
}

func (iconv *Iconv) Close() error {
	_, err := C.iconv_close(iconv.pointer)
	return err
}

func (iconv *Iconv) Convert(inbuf []byte) ([]byte, error) {
	if len(inbuf) == 0 {
		return inbuf, nil
	}

	inbytes := C.size_t(len(inbuf))
	outbuf := make([]byte, inbytes*6)
	outbytes := C.size_t(len(outbuf))
	inptr := (*C.char)(unsafe.Pointer(&inbuf[0]))
	outptr := (*C.char)(unsafe.Pointer(&outbuf[0]))

	_, err := C.iconv(iconv.pointer, &inptr, &inbytes, &outptr, &outbytes)
	if err != nil {
		return nil, err
	}
	return outbuf[:len(outbuf)-int(outbytes)], nil
}

func ConvertEncoding(input, fromcode, tocode string) (string, error) {
	iconv, err := Open(fromcode, tocode)
	if err != nil {
		return "", err
	}
	defer iconv.Close()

	b, err := iconv.Convert([]byte(input))
	if err != nil {
		return "", err
	}
	return string(b), nil
}

func main() {
	text := "てすと"
	text_sjis, _ := ConvertEncoding(text, "UTF-8", "Shift-JIS")
	println(text_sjis)
	text_utf8, _ := ConvertEncoding(text_sjis, "Shift-JIS", "UTF-8")
	println(text_utf8)
}