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c++, cout and UTF-8

Tags:

c++

utf-8

cout

Hopefully a simple question: cout seems to die when handling strings that end with a multibyte UTF-8 char, am I doing something wrong? This is with GCC (Mingw) on Win7 x64.

**Edit Sorry if I wasn't clear enough, I'm not concerned about the missing glyphs or how the bytes are interpreted, merely that they are not showing at all right after the call to cout << s4 (missing BAR). Any further couts after the first display no text whatsoever!

#include <cstdio>
#include <iostream>
#include <string>

int main() {
    std::string s1("abc");
    std::string s2("…");  // … = 0xE2 80 A6
    std::string s3("…abc");
    std::string s4("abc…");

    //In C
    fwrite(s1.c_str(), s1.size(), 1, stdout);
    printf(" FOO ");
    fwrite(s2.c_str(), s2.size(), 1, stdout);
    printf(" BAR ");
    fwrite(s3.c_str(), s3.size(), 1, stdout);
    printf(" FOO ");
    fwrite(s4.c_str(), s4.size(), 1, stdout);
    printf(" BAR\n\n"); 

    //C++
    std::cout << s1 << " FOO " << s2 << " BAR " << s3 << " FOO " << s4 << " BAR ";
}

// results:

// abc FOO ��� BAR ���abc FOO abc… BAR

// abc FOO ��� BAR ���abc FOO abc…
like image 232
user657267 Avatar asked Aug 05 '11 09:08

user657267


2 Answers

If you want your program to use your current locale, call setlocale(LC_ALL, "") as the first thing in your program. Otherwise the program's locale is C and what it will do to non-ASCII characters is not knowable by us mere humans.

like image 55
n. 1.8e9-where's-my-share m. Avatar answered Oct 23 '22 10:10

n. 1.8e9-where's-my-share m.


This is really no surprise. Unless your terminal is set to UTF-8 coding, how does it know that s2 isn't supposed to be "(Latin small letter a with circumflex)(Euro sign)(Pipe)", supposing that your terminal is set to ISO-8859-1 according to http://www.ascii-code.com/

By the way, cout is not "dying" as it clearly continues to produce output after your test string.

like image 26
koan Avatar answered Oct 23 '22 10:10

koan