confused using swprintf and wstring

confused using swprintf and wstring

[James Gregory]

Here is my little test program:

#include <iostream>
#include <wchar.h>
#include <string>

using std::wcout;
using std::wstring;
using std::endl;

int main(char** argv, int argc) {
	wstring s = L"blah";
	wchar_t o[50];
	swprintf(o, 50, L"%s", s.c_str());
	wcout << o << endl;
}

I would expect it to produce write "blah" on the standard output, but
instead it writes "b". Why is this?

Thanks,

James

Re: confused using swprintf and wstring

[Joel Dice]

On Sat, 12 Jul 2008, James Gregory wrote:

> Here is my little test program:
>
> #include <iostream>
> #include <wchar.h>
> #include <string>
>
> using std::wcout;
> using std::wstring;
> using std::endl;
>
> int main(char** argv, int argc) {
> 	wstring s = L"blah";
> 	wchar_t o[50];
> 	swprintf(o, 50, L"%s", s.c_str());
> 	wcout << o << endl;
> }
>
> I would expect it to produce write "blah" on the standard output, but
> instead it writes "b". Why is this?

I think you want "%ls".

>
> Thanks,
>
> James

Re: confused using swprintf and wstring

[James Gregory]

On Sun, Jul 13, 2008 at 2:03 AM, Joel Dice <dicej@mailsnare.net> wrote:
> On Sat, 12 Jul 2008, James Gregory wrote:
>
>> Here is my little test program:
>>
>> #include <iostream>
>> #include <wchar.h>
>> #include <string>
>>
>> using std::wcout;
>> using std::wstring;
>> using std::endl;
>>
>> int main(char** argv, int argc) {
>>        wstring s = L"blah";
>>        wchar_t o[50];
>>        swprintf(o, 50, L"%s", s.c_str());
>>        wcout << o << endl;
>> }
>>
>> I would expect it to produce write "blah" on the standard output, but
>> instead it writes "b". Why is this?
>
> I think you want "%ls".
>

Ah thanks, you are correct (well, actually it is L"%ls"). Annoyingly
the first google hit for "swprintf" is an example from Microsoft which
does what I was doing.

James