I have a GUID variable and I want to write inside a text file its value. GUID definition is:
typedef struct _GUID { // size is 16
DWORD Data1;
In case you prefer C++ way
std::ostream& operator<<(std::ostream& os, REFGUID guid){
os << std::uppercase;
os.width(8);
os << std::hex << guid.Data1 << '-';
os.width(4);
os << std::hex << guid.Data2 << '-';
os.width(4);
os << std::hex << guid.Data3 << '-';
os.width(2);
os << std::hex
<< static_cast<short>(guid.Data4[0])
<< static_cast<short>(guid.Data4[1])
<< '-'
<< static_cast<short>(guid.Data4[2])
<< static_cast<short>(guid.Data4[3])
<< static_cast<short>(guid.Data4[4])
<< static_cast<short>(guid.Data4[5])
<< static_cast<short>(guid.Data4[6])
<< static_cast<short>(guid.Data4[7]);
os << std::nouppercase;
return os;
}
Usage:
static const GUID guid =
{ 0xf54f83c5, 0x9724, 0x41ba, { 0xbb, 0xdb, 0x69, 0x26, 0xf7, 0xbd, 0x68, 0x13 } };
std::cout << guid << std::endl;
Output:
F54F83C5-9724-41BA-BBDB-6926F7BD6813
I know the question is quite old, but would this work maybe?
inline std::ostream& operator <<(std::ostream& ss,GUID const& item) {
OLECHAR* bstrGuid;
::StringFromCLSID(item, &bstrGuid);
ss << bstrGuid;
::CoTaskMemFree(bstrGuid);
return ss;
}
printf(%X-%X-%X-%X-%X", guid.Data1, guid.Data2, guid.Data3, &guid.Data4);
Inspired by JustinB's answer
#define GUID_FORMAT "%08lX-%04hX-%04hX-%02hhX%02hhX-%02hhX%02hhX%02hhX%02hhX%02hhX%02hhX"
#define GUID_ARG(guid) guid.Data1, guid.Data2, guid.Data3, guid.Data4[0], guid.Data4[1], guid.Data4[2], guid.Data4[3], guid.Data4[4], guid.Data4[5], guid.Data4[6], guid.Data4[7]
and then
printf("Int = %d, string = %s, GUID = {" GUID_FORMAT "}\n", myInt, myString, GUID_ARG(myGuid));
std::string
GuidToString(const GUID& guid, bool lower = false)
{
const char* hexChars = lower ? "0123456789abcdef" : "0123456789ABCDEF";
auto f = [hexChars](char* p, unsigned char v)
{
p[0] = hexChars[v >> 4];
p[1] = hexChars[v & 0xf];
};
char s[36];
f(s, static_cast<unsigned char>(guid.Data1 >> 24));
f(s + 2, static_cast<unsigned char>(guid.Data1 >> 16));
f(s + 4, static_cast<unsigned char>(guid.Data1 >> 8));
f(s + 6, static_cast<unsigned char>(guid.Data1));
s[8] = '-';
f(s + 9, static_cast<unsigned char>(guid.Data2 >> 8));
f(s + 11, static_cast<unsigned char>(guid.Data2));
s[13] = '-';
f(s + 14, static_cast<unsigned char>(guid.Data3 >> 8));
f(s + 16, static_cast<unsigned char>(guid.Data3));
s[18] = '-';
f(s + 19, guid.Data4[0]);
f(s + 21, guid.Data4[1]);
s[23] = '-';
f(s + 24, guid.Data4[2]);
f(s + 26, guid.Data4[3]);
f(s + 28, guid.Data4[4]);
f(s + 30, guid.Data4[5]);
f(s + 32, guid.Data4[6]);
f(s + 34, guid.Data4[7]);
return std::string(s, 36);
}