printf_s to print the non-initialized variable in debug mode

I found it today when I debug the kernel output.

The printf_s output is normal when printing a variable that has already been initialized, but there is unexpected data when the print is uninitialized.

This is the original code.

Char buf[];    DWORD Bfread;     &Bfread, NULL);      for (int0; i++)    {        printf_s ("%x\n", Buf[i]);    }

The output is the same as

Supposedly a char for a byte, the output cannot be 4 bytes, so I opened with OL

This is the main entry function

The key is to movsx this instruction, he expands a symbol bit byte into eax, and then prints it out.

This makes it obvious that the actual printf_s function expands the data symbol to 32 bits before printing.

So I continue, if initialized, then when the initial, change the original code and then open

Initialize at the original code definition, not as I originally expected at the beginning of the main function initialization ~ ~

printf_s to print the non-initialized variable in debug mode