On Wed, 2011-06-29 at 14:41 +0200, Axel Freyn wrote:
> Hi Eric,
> > Would you please post your test os(linux kernel version) and which g++
> > version you use, especially when you pass the test
> > -------------
> > #include <iostream>
> > #include <fstream>
> > #include <string>
> > //#include <cstring>
> >
> > using namespace std;
> > int main(int argc, char *argv[]) {
> >
> > /* try {
> > std::locale::global(std::locale(""));
> > } catch ( ... ) { }; */
> >
> > wstring ws2 = L"Euro: \x20ac";
> > wofstream out("unicode.txt");
> > if(not out.good())
> > cerr << "Error opening output file" << endl;
> > //const char *name = "el_GR.utf8";
> > const char *name = "en_US.utf8";
> > if(argc == 2)
> > name = argv[1];
> > cout << "trying to access locale " << name << endl;
> > locale loc;
> > try{
> > loc = locale(name);
> > cout << "Generated locale " << loc.name() << endl;
> > }catch( exception &e){
> > cerr << "Couldn't generate locale " << name << ": " << e.what() <<
> > endl;
> > }
> > out.imbue(loc);
> > if(not out.good())
> > cerr << "Error when setting the locale" << endl;
> > out << ws2<< endl;
> > if(not out.good())
> > cerr << "Error when writing to file" << endl;
> > }
> > ------------
>
> You could try to run the test-program with "strace", like
> strace ./test en_US.utf8
> this tells at least what the code is trying to do while loading the
> encoding. On my machine I get the following for an EXISTING encoding:
>
> open("unicode.txt", O_WRONLY|O_CREAT|O_TRUNC, 0666) = 3
> fstat(1, {st_mode=S_IFCHR|0620, st_rdev=makedev(136, 3), ...}) = 0
> mmap(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7fb8588e6000
> write(1, "trying to access locale fr_FR.ut"..., 35trying to access locale fr_FR.utf8
> ) = 35
> open("/usr/lib/locale/locale-archive", O_RDONLY) = 4
> fstat(4, {st_mode=S_IFREG|0644, st_size=1527584, ...}) = 0
> mmap(NULL, 1527584, PROT_READ, MAP_PRIVATE, 4, 0) = 0x7fb85875d000
> close(4) = 0
> open("/usr/lib/gconv/gconv-modules.cache", O_RDONLY) = 4
> fstat(4, {st_mode=S_IFREG|0644, st_size=26048, ...}) = 0
> mmap(NULL, 26048, PROT_READ, MAP_SHARED, 4, 0) = 0x7fb8588df000
> close(4) = 0
> write(1, "Generated locale fr_FR.utf8\n", 28Generated locale fr_FR.utf8
> ) = 28
>
>
> And for a NON-EXISTING encoding (fr_FF.utf8):
>
> open("unicode.txt", O_WRONLY|O_CREAT|O_TRUNC, 0666) = 3
> fstat(1, {st_mode=S_IFCHR|0620, st_rdev=makedev(136, 3), ...}) = 0
> mmap(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7fc99aff4000
> write(1, "trying to access locale fr_FF.ut"..., 35trying to access locale fr_FF.utf8
> ) = 35
> open("/usr/lib/locale/locale-archive", O_RDONLY) = 4
> fstat(4, {st_mode=S_IFREG|0644, st_size=1527584, ...}) = 0
> mmap(NULL, 1527584, PROT_READ, MAP_PRIVATE, 4, 0) = 0x7fc99ae6b000
> close(4) = 0
> open("/usr/share/locale/locale.alias", O_RDONLY) = 4
> fstat(4, {st_mode=S_IFREG|0644, st_size=2570, ...}) = 0
> mmap(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7fc99aff3000
> read(4, "# Locale name alias data base.\n#"..., 4096) = 2570
> read(4, "", 4096) = 0
> close(4) = 0
> munmap(0x7fc99aff3000, 4096) = 0
> open("/usr/lib/locale/fr_FF.utf8/LC_CTYPE", O_RDONLY) = -1 ENOENT (No such file or directory)
> open("/usr/lib/locale/fr_FF/LC_CTYPE", O_RDONLY) = -1 ENOENT (No such file or directory)
> open("/usr/lib/locale/fr.utf8/LC_CTYPE", O_RDONLY) = -1 ENOENT (No such file or directory)
> open("/usr/lib/locale/fr/LC_CTYPE", O_RDONLY) = -1 ENOENT (No such file or directory)
> write(2, "Couldn't generate locale ", 25Couldn't generate locale ) = 25
>
> So, I suggest for my machine:
> - it searches in "/usr/lib/locale/locale-archive" for the encoding
> - if it is found, it loads the encoding from "/usr/lib/gconv/gconv-modules.cache"
> - if it is NOT found, it searches for related directories in
> /usr/lib/locale/ , trying to open a file LC_CTYPE
>
> If your compiler/os/standard-library has working locale-support, I would
> expect it to do something similar -- if the locale-support is
> deactivated in the compiler, one should see it here.
>
> Other opinions?
>
> Axel
---------------------------------------------------------------
#include <iostream>
#include <fstream>
#include <string>
//#include <cstring>
using namespace std;
int main(int argc, char *argv[]) {
/* try {
std::locale::global(std::locale(""));
} catch ( ... ) { }; */
wstring ws2 = L"Euro: \x20ac";
wofstream out("unicode.txt");
if(not out.good())
cerr << "Error opening output file" << endl;
//const char *name = "el_GR.utf8";
const char *name = "en_US.utf8";
if(argc == 2)
name = argv[1];
cout << "trying to access locale " << name << endl;
locale loc;
try{
loc = locale(name);
cout << "Generated locale " << loc.name() << endl;
}catch( exception &e){
cerr << "Couldn't generate locale " << name << ": " << e.what() <<
endl;
}
out.imbue(loc);
if(not out.good())
cerr << "Error when setting the locale" << endl;
out << ws2<< endl;
if(not out.good())
cerr << "Error when writing to file" << endl;
open("unicode.txt", O_WRONLY|O_CREAT|O_TRUNC, 0666) = 3
fstat(1, {st_mode=S_IFCHR|0620, st_rdev=makedev(136, 3), ...}) = 0
mmap(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0)
= 0x7fb8588e6000
write(1, "trying to access locale fr_FR.ut"..., 35trying to access
locale fr_FR.utf8
) = 35
open("/usr/lib/locale/locale-archive", O_RDONLY) = 4
fstat(4, {st_mode=S_IFREG|0644, st_size=1527584, ...}) = 0
mmap(NULL, 1527584, PROT_READ, MAP_PRIVATE, 4, 0) = 0x7fb85875d000
close(4) = 0
open("/usr/lib/gconv/gconv-modules.cache", O_RDONLY) = 4
fstat(4, {st_mode=S_IFREG|0644, st_size=26048, ...}) = 0
mmap(NULL, 26048, PROT_READ, MAP_SHARED, 4, 0) = 0x7fb8588df000
close(4) = 0
write(1, "Generated locale fr_FR.utf8\n", 28Generated locale fr_FR.utf8
) = 28
}
------------------------------------
root@eric-laptop:/home/eric/cppcookbook# g++ testlocale1.cpp
testlocale1.cpp:39:49: error: invalid suffix "trying" on integer
constant
testlocale1.cpp:49:43: error: invalid suffix "Generated" on integer
constant
testlocale1.cpp: In function ‘int main(int, char**)’:
testlocale1.cpp:36:21: error: ‘O_WRONLY’ was not declared in this scope
testlocale1.cpp:36:30: error: ‘O_CREAT’ was not declared in this scope
testlocale1.cpp:36:38: error: ‘O_TRUNC’ was not declared in this scope
testlocale1.cpp:36:51: error: ‘open’ was not declared in this scope
testlocale1.cpp:37:1: error: expected ‘;’ before ‘fstat’
testlocale1.cpp:37:62: error: expected primary-expression before ‘)’
token
testlocale1.cpp:37:62: error: expected ‘;’ before ‘)’ token
testlocale1.cpp:42:54: error: expected primary-expression before ‘)’
token
testlocale1.cpp:42:54: error: expected ‘;’ before ‘)’ token
testlocale1.cpp:46:52: error: expected primary-expression before ‘)’
token
testlocale1.cpp:46:52: error: expected ‘;’ before ‘)’ token
----------------------------------------------------
plus, I get an email from someone who work in linux kernel 3.0 about
this locale issue on g++/ubuntu
--------
Hello Eric,
The kernel has nothing to do with this. It is a C++ library issue only.
Your code looks fine.
It seems that locale support is lacking in the STL that comes with g++
on many platforms. I tested it here on Mac OS X (Leopard) with GCC
4.0.1 and also found that it did not work.
I have only needed very little locale support in the projects I have
been involved in and I believe I used the C library functions when I
needed it, even though the project was C++.
It is sad really, but unless you have a lot of time on your hands to
fix the library, I guess there is not much to do about it :)
About the kernel, yes it is written in C and no, no part of it is
written in C++, nor is it likely to be any time soon.
I hope this helps.
----------------------------------------------
need more advice
and thanks a lot in advance
Eric
