如何在Linux / OS X上打印wstring？ [英] How to print wstring on Linux/OS X?

问题描述

如何在控制台/屏幕上打印如下字符串：€áa¢cée£？我试过：

How can I print a string like this: €áa¢cée£ on the console/screen? I tried this:

#include <iostream>    
#include <string>
using namespace std;

wstring wStr = L"€áa¢cée£";

int main (void)
{
    wcout << wStr << " : " << wStr.length() << endl;
    return 0;
}

这不工作。甚至混乱，如果我从字符串中删除€，打印输出如下：？a？c？e？ ：7 但在字符串中€，则在€字符后不打印任何内容。

which is not working. Even confusing, if I remove € from the string, the print out comes like this: ?a?c?e? : 7 but with € in the string, nothing gets printed after the € character.

如果我在python中编写相同的代码：

If I write the same code in python:

#!/usr/bin/env python
# -*- coding: utf-8 -*-

wStr = u"€áa¢cée£"
print u"%s" % wStr

它在同一控制台上正确打印字符串。我在c ++中丢失了什么（好吧，我只是一个noob）？干杯！！

it prints out the string correctly on the very same console. What am I missing in c++ (well, I'm just a noob)? Cheers!!

---

更新1：。

#include <iostream>
#include <string>
using namespace std;

string wStr = "€áa¢cée£";
char *pStr = 0;

int main (void)
{
    cout << wStr << " : " << wStr.length() << endl;

    pStr = &wStr[0];
    for (unsigned int i = 0; i < wStr.length(); i++) {
        cout << "char "<< i+1 << " # " << *pStr << " => " << pStr << endl;
        pStr++;
    }
    return 0;
}

首先，它报告 14 作为字符串的长度：€áa¢cée£：14 是因为它计数每个字符2个字节？

First of all, it reports 14 as the length of the string: €áa¢cée£ : 14 Is it because it's counting 2 byte per character?

所有我得到这个：

char 1 # ? => €áa¢cée£
char 2 # ? => ??áa¢cée£
char 3 # ? => ?áa¢cée£
char 4 # ? => áa¢cée£
char 5 # ? => ?a¢cée£
char 6 # a => a¢cée£
char 7 # ? => ¢cée£
char 8 # ? => ?cée£
char 9 # c => cée£
char 10 # ? => ée£
char 11 # ? => ?e£
char 12 # e => e£
char 13 # ? => £
char 14 # ? => ?

作为最后一个cout输出。所以，实际问题仍然存在，我相信。 Cheers !!

as the last cout output. So, actual problem still remains, I believe. Cheers!!

更新2：

Update 2: based on n.m.'s second suggestion

#include <iostream>
#include <string>

using namespace std;

wchar_t wStr[] = L"€áa¢cée£";
int iStr = sizeof(wStr) / sizeof(wStr[0]);        // length of the string
wchar_t *pStr = 0;

int main (void)
{
    setlocale (LC_ALL,"");
    wcout << wStr << " : " << iStr << endl;

    pStr = &wStr[0];
    for (int i = 0; i < iStr; i++) {
       wcout << *pStr << " => " <<  static_cast<void*>(pStr) << " => " << pStr << endl;
       pStr++;
    }
    return 0;
}

这是我得到的结果：

€áa¢cée£ : 9
€ => 0x1000010e8 => €áa¢cée£
á => 0x1000010ec => áa¢cée£
a => 0x1000010f0 => a¢cée£
¢ => 0x1000010f4 => ¢cée£
c => 0x1000010f8 => cée£
é => 0x1000010fc => ée£
e => 0x100001100 => e£
£ => 0x100001104 => £
 => 0x100001108 => 

为什么会报告为 9 code> 8 ？或者这是我应该期望？干杯！！

Why there it's reported as 9 than 8? Or this is what I should expect? Cheers!!

推荐答案

在字符串文字之前删除 L 使用 std :: string ，而不是 std :: wstring 。

Drop the L before the string literal. Use std::string, not std::wstring.

UPD：有一个更好的（正确的）解决方案。保持wchar_t，wstring和L，并在程序开始调用 setlocale（LC_ALL，）。

UPD: There's a better (correct) solution. keep wchar_t, wstring and the L, and call setlocale(LC_ALL,"") in the beginning of your program.

你应该在程序的开始调用 setlocale（LC_ALL，）。这将指示您的程序使用您的环境的语言环境，而不是默认的C语言环境。

You should call setlocale(LC_ALL,"") in the beginning of your program anyway. This instructs your program to work with your environment's locale, instead of the default "C" locale. Your environment has a UTF-8 one so everything should work.

没有调用 setlocale（LC_ALL，） ，该程序使用UTF-8序列工作，没有实现，他们是UTF-8。如果在终端上打印了正确的UTF-8序列，它将被解释为UTF-8，并且一切都会很好。这是如果你使用 string 和 char 会发生什么：gcc使用UTF-8作为字符串的默认编码， ostream愉快地打印它们而不应用任何转换。它认为它有一个ASCII字符序列。

Without calling setlocale(LC_ALL,""), the program works with UTF-8 sequences without "realizing" that they are UTF-8. If a correct UTF-8 sequence is printed on the terminal, it will be interpreted as UTF-8 and everything will look fine. That's what happens if you use string and char: gcc uses UTF-8 as a default encoding for strings, and the ostream happily prints them without applying any conversion. It thinks it has a sequence of ASCII characters.

但是当你使用 wchar_t 时，一切都会断裂：gcc使用UTF-32，正确的重新编码不是

But when you use wchar_t, everything breaks: gcc uses UTF-32, the correct re-encoding is not applied (because the locale is "C") and the output is garbage.

当你调用 setlocale（LC_ALL，）程序知道它应该重新编码UTF-32到UTF-8，一切都很好，dandy再次。

When you call setlocale(LC_ALL,"") the program knows it should recode UTF-32 to UTF-8, and everything is fine and dandy again.

这一切假设我们只想要使用UTF-8。使用任意语言环境和编码超出了此答案的范围。

This all assumes that we only ever want to work with UTF-8. Using arbitrary locales and encodings is beyond the scope of this answer.

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