#include <WinAPI.au3>

;init DLL function, we need handle to call the function
$h = DllCall("Kernel32.dll", "hwnd", "CreateFile", "str", "\\.\COM2", "int", BitOR($GENERIC_READ,$GENERIC_WRITE), "int", 0, "ptr", 0, "int", $OPEN_EXISTING, "int", $FILE_ATTRIBUTE_NORMAL, "int", 0)
$handle=$h[0]

;$res= SetError(_WinAPI_GetLastError(), 0, $h[0])
ConsoleWrite("handle=" & $handle & @LF)



;write String
func writeString($handle,$str)
	for $i=0 to stringlen($str)
		writeChar($handle,StringMid($str,$i,1))
	next
EndFunc

;write a single char
func writeChar($handle,$c)
    $stString       = DLLStructCreate("char str")
	$lpNumberOfBytesWritten = 0
    DllStructSetData($stString, 1, $c)
	$res = _WinAPI_WriteFile($handle, DllStructGetPtr($stString, "str"), 1, $lpNumberOfBytesWritten)	;overlapped=0 ?
	if ($res<>true) then
		ConsoleWrite ( _WinAPI_GetLastErrorMessage() & @LF)
	EndIf
EndFunc

;read a line (string ending with @LF) but don't wait for it
Func readLineNoBlock($handle)
	$inputLine = ""
	while(true)
		$str = readCharNoBlock($handle)
		$inputLine = $inputLine & $str
		if $str=@LF or $str="" then
			return $inputLine
		EndIf
		sleep(50)
	wend	
endfunc

;read a line (string ending with @LF) and wait for it
Func readLineBlock($handle)
	$inputLine = ""
	while(true)
		$str = readCharBlock($handle)
		$inputLine = $inputLine & $str
		if $str=@LF then
			return $inputLine
		EndIf
		sleep(50)
	wend	
endfunc

;read a single char, and wait for it
func readCharBlock($handle)
	$numBytes = 1
	$lpBuffer       = DLLStructCreate("char w")	;create struct to hold the read data
	$lpNumberOfBytesRead = 0					;will contain the number of chars read
	
	while ($lpNumberOfBytesRead<=0)
		$res=_WinAPI_ReadFile($handle, DllStructGetPtr($lpBuffer, "w"), $numBytes, $lpNumberOfBytesRead)	;read one char
		if (not $res) Then
			ConsoleWrite("error  " &  _WinAPI_GetLastErrorMessage() & @LF)
			ConsoleWrite($lpNumberOfBytesRead & @LF)
			return ""
		EndIf
		
		if ($lpNumberOfBytesRead>0) then		;if a char is read
			$str =  DllStructGetData($lpBuffer, "w")	;return the char
			return $str
		EndIf
	WEnd
EndFunc

;read a single char, but don't wait for it ("" if nothing)
Func readCharNoBlock($handle)
	$numBytes = 1
	$lpBuffer       = DLLStructCreate("char w")	;create struct to hold the read data
	$lpNumberOfBytesRead = 0					;will contain the number of chars read
	$res=_WinAPI_ReadFile($handle, DllStructGetPtr($lpBuffer, "w"), $numBytes, $lpNumberOfBytesRead)	;read one char
	if ($res) then								;if no error
		if ($lpNumberOfBytesRead>0) then		;if a char is read
			$str =  DllStructGetData($lpBuffer, "w")	;return the char
			return $str
		else 
			return ""
		EndIf
	Else
		ConsoleWrite( _WinAPI_GetLastErrorMessage() & @LF)
		ConsoleWrite($lpNumberOfBytesRead & @LF)
		return ""
	EndIf
EndFunc