golang 分享一个将 windows 记事本各种编码文字转成 utf8

# 起初想用 unoconv 将各类文档转成 pdf,txt 确实是一头包。这个方法基本可以将 txt 4 种格式都统一起来。 注意 linux 下需设置
#
# LANG C.UTF-8
#

package until

import (
	"unicode/utf16"
	"bytes"
	"golang.org/x/text/encoding/simplifiedchinese"
	"golang.org/x/text/transform"
	"io/ioutil"
)

func Utf16toString(b []uint8) (string) {
	if len(b)&1 != 0 {
		return string(b)
	}
	var bom int
	if len(b) >= 2 {
		switch n := int(b[0])<<8 | int(b[1]); n {
		case 0xfffe:
			bom = 1
			fallthrough
		case 0xfeff:
			b = b[2:]
			w := make([]uint16, len(b)/2)
			for i := range w {
				w[i] = uint16(b[2*i+bom&1])<<8 | uint16(b[2*i+(bom+1)&1])
			}
			return string(utf16.Decode(w))
		default:
			gbk, _ := GbkToUtf8(b)
			return string(gbk)
		}
	} else {
		return string(b)
	}

}

func GbkToUtf8(s []byte) ([]byte, error) {
	reader := transform.NewReader(bytes.NewReader(s), simplifiedchinese.GBK.NewDecoder())
	d, e := ioutil.ReadAll(reader)
	if e != nil {
		return nil, e
	}
	return d, nil
}