Hello

I want to convert a char* buffer to a std::string containing a hex
description of it. I use a std::stringstream in the following manner:

std::tstring ToHex( const char* buffer, size_t size, bool withSize )
{
std::tstringstream str;
str.setf(std::ios_base::hex, std::ios::basefield);
str.setf(std::ios_base::uppercase);
str.fill( _T('0') );

for ( size_t i=0; i<size; ++i )
{
str << std::hex << std::setw(2) << (unsigned short)buffer[i];
}
return str.str();
}

int main()
{
char buffer[255];
for ( int i=0; i<sizeof buffer; ++i )
{
buffer[i] = i;
}
const std::tstring hex = ToHex( buffer, sizeof buffer, true );
std::cout << hex.c_str() << std::endl;
}

The problem is that for values bigger that 127 (0x7F) the hex elements
are padded with 0xFF (like FF80 FF81 etc). It is even if I cast to
unsigned int or int. I'd like to have values 7E 7F 80 81 ... etc. How
to fix it?

Thanks
dominolog

On Thu, 28 Aug 2008 08:55:29 -0700, dominolog wrote:

Hello
>
I want to convert a char* buffer to a std::string containing a hex
description of it. I use a std::stringstream in the following manner:
>
std::tstring ToHex( const char* buffer, size_t size, bool withSize ) {
std::tstringstream str;

What are std::tstring and std::tstringstream? Last time
I checked the std namespace, there were no such things.

--
OU

On 28 Sie, 18:15, Obnoxious User <O...@127.0.0.1wrote:

On Thu, 28 Aug 2008 08:55:29 -0700, dominolog wrote:

>

>

>
What are std::tstring and std::tstringstream? Last time
I checked the std namespace, there were no such things.
>
--
OU

Oh, sorry. It is my "extension". They are simply

namespace std
{
#ifdef _UNICODE
typedef wstring tstring;
typedef wstringstream tstringstream;
#else
typedef string tstring;
typedef stringstream tstringstream;
#endif
}

On 28 Aug, 16:55, dominolog <dominiktomc...@gmail.comwrote:

The problem is that for values bigger that 127 (0x7F) the hex elements
are padded with 0xFF (like FF80 FF81 etc). It is even if I cast to
unsigned int or int. I'd like to have values 7E 7F 80 81 ... etc. How
to fix it?
>
Thanks
dominolog

Remove the sign from your char before casting it to a short

for ( size_t i=0; i<size; ++i )
{
str << std::hex << std::setw(2) << (unsigned short)(unsigned
char)buffer[i];
}
return str.str();

Or store you hex bytes in an unsigned char array to start with.

(And you can - of course - remove the << std::hex as you've already
set hex-mode using setf)

Andy

On 30 Sie, 18:52, andy_west...@hotmail.com wrote:

On 28 Aug, 16:55, dominolog <dominiktomc...@gmail.comwrote:
>

>

>
Remove the sign from your char before casting it to a short
>
* * for ( size_t i=0; i<size; ++i )
* * {
* * * * str << std::hex << std::setw(2) << (unsigned short)(unsigned
char)buffer[i];
* * }
* * return str.str();
>
Or store you hex bytes in an unsigned char array to start with.
>
(And you can - of course - remove the << std::hex as you've already
set hex-mode using setf)
>
Andy

Thanks. It works. !!!!