8 bytes data reading from binary file

Dear all,

I think it is simple program. But I really face problem and tired out of finding solution. So, I really need your help.

Here is the problem.
I saved 7E FF FF FF FF FF FF 7E (8 bytes) data in binary file.
I would like to retrieve it as reverse order with binary file.

The following is output function.

void outputint64(int i) {
	__int64 app1 = (__int64)mem[i+3] << 48; //mem is short type array data read from binary file
	__int64 app2 = (__int64)mem[i+2] << 32;
	__int64 app3 = (__int64)mem[i+1] << 16;
	__int64 app4 = (__int64)mem[i];
	__int64 app = (__int64)app1 | (__int64)app2 | (__int64)app3 | (__int64)app4;
	printf("int64 value is : %I64x", app);
}

app1 output is 0x 7E FF 00 00 00 00 00 00 //the output is as I expect
app2 output is 0x FF FF FF FF 00 00 00 00 //actually I only expect 0x 00 00 FF FF 00 00 00 00
app3 output is 0x FF FF FF FF FF FF 00 00 //actually I only expect 0x 00 00 00 00 FF FF 00 00
app4 output is 0x FF FF FF FF FF FF FF 7E //actually I only expect 0x 00 00 00 00 00 00 FF 7E

So, app output becomes 0x FF FF FF FF FF FF FF 7E, even though I expect as 0x 7E FF FF FF FF FF FF 7E.

How should I modify to get the expected result?
If you have any idea, please help me.

Thanks in advance.

Tags: C++