在Go中读取非UTF-8文本文件

Question

我需要阅读一个以GBK编码的文本文件。Go编程语言中的标准库假定所有文本均以UTF-8编码。

如何读取其他编码的文件？

Answer 1

以前（如在较早的答案中所述），“简单”的方法是使用需要cgo并包装iconv库的第三方程序包。由于许多原因，这是不希望的。值得庆幸的是，有一段时间以来，仅使用Go
Authors提供的软件包（不是在主要软件包中，而是在Go子存储库中），就有了一种上乘的Go语言方法。

该golang.org/x/text/encoding软件包定义了一个通用字符编码的接口，该接口可以与UTF-8进行相互转换。该golang.org/x/text/encoding/simplifiedchinese子程序包提供GB18030，GBK和HZ-
GB2312
编码实现。

这是读取和写入GBK编码文件的示例。请注意，在读取/写入数据时，“ io.Reader和io.Writer”进行“即时”编码。

package main

import (
    "bufio"
    "fmt"
    "log"
    "os"

    "golang.org/x/text/encoding/simplifiedchinese"
    "golang.org/x/text/transform"
)

// Encoding to use. Since this implements the encoding.Encoding
// interface from golang.org/x/text/encoding you can trivially
// change this out for any of the other implemented encoders,
// e.g. `traditionalchinese.Big5`, `charmap.Windows1252`,
// `korean.EUCKR`, etc.
var enc = simplifiedchinese.GBK

func main() {
    const filename = "example_GBK_file"
    exampleWriteGBK(filename)
    exampleReadGBK(filename)
}

func exampleReadGBK(filename string) {
    // Read UTF-8 from a GBK encoded file.
    f, err := os.Open(filename)
    if err != nil {
        log.Fatal(err)
    }
    r := transform.NewReader(f, enc.NewDecoder())

    // Read converted UTF-8 from `r` as needed.
    // As an example we'll read line-by-line showing what was read:
    sc := bufio.NewScanner(r)
    for sc.Scan() {
        fmt.Printf("Read line: %s\n", sc.Bytes())
    }
    if err = sc.Err(); err != nil {
        log.Fatal(err)
    }

    if err = f.Close(); err != nil {
        log.Fatal(err)
    }
}

func exampleWriteGBK(filename string) {
    // Write UTF-8 to a GBK encoded file.
    f, err := os.Create(filename)
    if err != nil {
        log.Fatal(err)
    }
    w := transform.NewWriter(f, enc.NewEncoder())

    // Write UTF-8 to `w` as desired.
    // As an example we'll write some text from the Wikipedia
    // GBK page that includes Chinese.
    _, err = fmt.Fprintln(w,
        `In 1995, China National Information Technology Standardization
Technical Committee set down the Chinese Internal Code Specification
(Chinese: 汉字内码扩展规范（GBK）; pinyin: Hànzì Nèimǎ
Kuòzhǎn Guīfàn (GBK)), Version 1.0, known as GBK 1.0, which is a
slight extension of Codepage 936. The newly added 95 characters were not
found in GB 13000.1-1993, and were provisionally assigned Unicode PUA
code points.`)
    if err != nil {
        log.Fatal(err)
    }

    if err = f.Close(); err != nil {
        log.Fatal(err)
    }
}

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