从连接中读取使用Go编码的utf8数据

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英文:

Reading utf8-encoded data from a connection, using Go

问题

我可以使用io.WriteString轻松地将字符串写入连接。

然而,我似乎无法轻松地从连接中读取字符串。我只能从连接中读取字节,然后必须将其转换为字符串。

假设这些字节表示一个utf8编码的字符串,我该如何将它们转换为字符串形式?

(编辑:或者,我如何简单地从连接中读取一个字符串?)

谢谢!

英文:

I can easily write a string to a connection using io.WriteString.

However, I can't seem to easily read a string from a connection. The only thing I can read from the connection are bytes, which, it seems, I must then somehow convert into a string.

Assuming the bytes represent a utf8-encoded string, how would I convert them to string form?

(Edit: alternatively, how could I simply read a string from a connection?)

Thanks!

答案1

得分: 4

在标准库中可以找到一个适合你目的的方便工具:bytes.Buffer请参阅包文档)。

假设你有一个实现了io.Reader接口的对象(也就是说,它有一个具有Read([]byte) (int, os.Error)签名的方法)。

一个常见的例子是os.File

f, err := os.Open("/etc/passwd", os.O_RDONLY, 0644)

如果你想将该文件的内容读取到一个字符串中,只需创建一个bytes.Buffer(它的零值是一个可用的缓冲区,所以你不需要调用构造函数):

var b bytes.Buffer

使用io.Copy将文件的内容复制到缓冲区中:

n, err := io.Copy(b, f)

(使用b.ReadFrom(f)是使用io.Copy的另一种选择 - 它们基本上是相同的。)

然后调用缓冲区的String方法将缓冲区的内容作为字符串检索出来:

s := b.String()

bytes.Buffer会自动增长以存储文件的内容,所以你不需要担心分配和增长byte切片等问题。

英文:

A handy tool that will suit your purpose can be found in the standard library: bytes.Buffer (see the package docs).

Say you have an object that implements io.Reader (that is, it has a method with the signature Read([]byte) (int, os.Error)).

A common example is an os.File:

f, err := os.Open("/etc/passwd", os.O_RDONLY, 0644)

If you wanted to read the contents of that file into a string, simply create a bytes.Buffer (its zero-value is a ready-to-use buffer, so you don't need to call a constructor):

var b bytes.Buffer

Use io.Copy to copy the file's contents into the buffer:

n, err := io.Copy(b, f)

(An alternative to using io.Copy would be b.ReadFrom(f) - they're more or less the same.)

And call the buffer's String method to retrieve the buffer's contents as a string:

s := b.String()

The bytes.Buffer will automatically grow to store the contents of the file, so you don't need to worry about allocating and growing byte slices, etc.

答案2

得分: 2

你可以将字节切片直接转换为字符串:

var foo []byte
var bar string = string(foo)

这里没有涉及编码/解码,因为字符串只是字节的数组。

英文:

You can just cast a slice of bytes into a string:

var foo []byte
var bar string = string(foo)

There is no encoding/decoding involved, because strings are just treated as arrays of bytes.

huangapple
  • 本文由 发表于 2010年8月2日 01:42:39
  • 转载请务必保留本文链接:https://go.coder-hub.com/3383060.html
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