How can I stop my Windows console application triggers beeps when displaying binary data

Question

I wrote a windows console application that receives binary data from a third party provider. For Debug and logging purposes, I display the binary data on the output (the console).

Unfortunately when the character 7 is displayed it triggers a beep. Here is a code that can trigger it:

int main(int argc, char** argv)
{
  char c = 7;
  std::cout << c;
}

My question is simple, is there a way to disable the beeps ?

Thanks

Answer 1

You could unplug the beeper in your computer.

If that is not an option: If you have a method debug(String s) that outputs the string s, you could replace character 7 by something else to avoid the beep.

Another way would be to output the text in hexadecimal form.

Answer 2

There is a lot of other values that will trigger weird things (depending on what terminal you use). You should check each char with isprint before outputting it. Better yet is a function like:

void memdump( std::ostream& o, const void* data, size_t len )
{
        const unsigned char* ptr = static_cast<const unsigned char*>(data);

        for( size_t i = 0; i < len; i += 16 )
        {
                o << std::setw(8);
                o << std::setfill('0');
                o << std::hex << i << ' ';
                size_t to = std::min(len,i+16);
                for( size_t j = i; j < to; ++j )
                {
                        o << ' ';
                        o << std::setw(2);
                        o << std::setfill('0');
                        o << std::hex;
                        o << (unsigned)ptr[j];

                        if( (j+1) % 8 == 0 )
                        {
                                o << ' ';
                        }
                }
                o << "  ";
                for( size_t j = to; j < i+16; ++j )
                {
                        o << "   ";
                        if( (j+1) % 8 == 0 )
                        {
                                o << ' ';
                        }
                }

                for( size_t j = i; j < to; ++j )
                {
                        if(isprint(ptr[j]))
                        {
                                o << ptr[j];
                        }
                        else
                        {
                                o << '.';
                        }
                        if( (j+1) % 8 == 0 )
                        {
                                o << ' ';
                        }
                }
                o << '\n';
        }
        o << std::dec;
}

Answer 3

A way to disable the beeper (at a Windows command line):

net stop beep

It should disable beeps temporarily. If you want the full effect (re-applies on reboot) type this:

sc config beep start= disabled

Answer 4

char c = 7; is a BELL according to ASCII if you want to display the 7 then you need to wrap it in single quotations marks (or how they are called:

char c = '7';

If you don't want to display a 7 then you need to remove the character 0x07 or replace it with (for example with '') (http://www.asciitable.com/)

Answer 5

Select a code page that interprets the character 7 as a glyph instead of a control character. See my other answer for details.