Re: Unicode string

[eric <fsshl at att dot net>]

On Sun, 2011-06-26 at 16:37 +0100, Jonathan Wakely wrote:
> On 26 June 2011 16:09, eric wrote:
> > On Sun, 2011-06-26 at 16:52 +0200, Axel Freyn wrote:
> >> Hi Eric,
> >>
> >> On Sun, Jun 26, 2011 at 07:15:54AM -0700, eric wrote:
> >> > Dear c/g++ advanced programers:
> >> >  I copied and tried to test a piece simple code which is used for
> >> > (Hardcoding a Unicode String) from the book (
> >> > C++ Cookbook) by D. Ryan Stephens, Christopher Diggins, Jonathan
> >> > Turkanis, and Jeff Cogswell
> >> > at Chapter 13, Internationalization, section 1: Hardcoding a Unicode
> >> > String
> >> > example 13-1, it can compile and run on my g++4.5.2, but I don't quite
> >> > satisfy its result
> >> >
> >> > --------------------
> >> > //Example 13-1 Hardcoding a Unicode string
> >> > #include <iostream>
> >> > #include <fstream>
> >> > #include <string>
> >> >
> >> > using namespace std;
> >> >
> >> > int main() {
> >> >
> >> >  // Create some strings with Unicode characters
> >> >  wstring ws1 = L"Infinity: \u221E";
> >> >  wstring ws2 = L"Euro: \u0128";
> >> >
> >> >  wchar_t w[] = L"Infinity: \u221E";
> >> >
> >> >  wofstream out("tmp\\unicode.txt");
> >> >  out << ws2 << endl;
> >> >  wcout << ws2 << endl;
> >> > }
> >> As far as I know, you should absolutely NOT use non-ascii characters in
> >> input/output operations without explicitely specifying the
> >> encoding/localization to be used.
> >> In your example, I would thus propose to add after the "wofstream
> >> out..." a line like
> >>  out.imbue(locale("de_DE.UTF-8"));
> >> which defines the encoding.
> >> The following works for me:
> >>
> >> #include <iostream>
> >> #include <fstream>
> >> #include <string>
> >> using namespace std;
> >> int main() {
> >>  wstring ws2 = L"Euro:\x20ac";
> >>  wofstream out("unicode.txt");
> >>  out.imbue(locale("de_DE.UTF-8"));
> >>  out << ws2<< endl;
> >> }
> >>
> >> (besides, the Euro-symbol in Unicode is \x20ac)
> >>
> >>
> >> In addition, you SHOULD add error-checking to your code. If you add
> >>   if(not out.good())
> >>     cerr << "Error while writing " << endl;
> >> AFTER the line which writes into the file, you'll get an error message ....
> >>
> >> HTH,
> >>
> >> Axel
> >>
> > ---------------------------
> > Dear Axel:
> >  Thanks your reply.
> >  I copied your code and tried on my system.  It compile and run, but
> > reponse by
> > ---------------------------
> > root@eric-laptop:/home/eric/cppcookbook# ./a.out
> > terminate called after throwing an instance of 'std::runtime_error'
> >  what():  locale::facet::_S_create_c_locale name not valid
> > Aborted
> > --------
> > Do you konw what can be improved more?
> 
> You probably don't have the de_DE.UTF-8 locale installed.  Try running
> 'locale -a' to see which locales you have installed and pick a utf8
> one, e.g. en_US.utf8
> 
> > looking to see your(or any advancer's) suggestion again, thanks a lot
> > in advance, Eric
> 
> That word still doesn't mean anything.
------------------------------------------------------------------
Dear g++ programers:

  I already check my locale and modify my code to include en_US.utf8 ,
however same kine error appear.  What may cause wrong.  
looking to see any experienced suggestion and thanks a lot in advance
Eric
-----------------------------------------------------------------
root@eric-laptop:/home/eric/cppcookbook# ./a.out
terminate called after throwing an instance of 'std::runtime_error'
  what():  locale::facet::_S_create_c_locale name not valid
Aborted
root@eric-laptop:/home/eric/cppcookbook# cat exam13-1-2.cpp
#include <iostream>
#include <fstream>
#include <string>
using namespace std;
int main() {
 wstring ws2 = L"Euro:\x20ac";
 wofstream out("unicode.txt");
 out.imbue(locale("en_US.utf8"));
 out << ws2<< endl;
}


root@eric-laptop:/home/eric/cppcookbook# locale -a
C
en_AG
en_AU.utf8
en_BW.utf8
en_CA.utf8
en_DK.utf8
en_GB.utf8
en_HK.utf8
en_IE.utf8
en_IN
en_NG
en_NZ.utf8
en_PH.utf8
en_SG.utf8
en_US.utf8
en_ZA.utf8
en_ZW.utf8
POSIX
------------------------