4 replies to this topic

[TheGood]

As the title says, I need the most efficient (read, fastest) way to retrieve a string if you only know its address and its length.
This is what I have right now:

sTest := "This is a test sentence."

MsgBox % PtrToStr(&sTest, StrLen(sTest))	;%

ExitApp

PtrToStr(ptr, len) {
	VarSetCapacity(s, len, 0)
	Loop %len%
		s .= Chr(*(ptr + A_Index - 1))
	Return s
}

Is there a faster way to do this?

Edit: I forgot to add, I tried messing around with RtlCopyString and RtlCopyBytes, but I get an ErrorLevel of -4 (function not found)

[Lexikos]

If the string is always null-terminated (as with all AutoHotkey strings), the easiest way is:

sTest := "This is a test sentence."
MsgBox % DllCall("MulDiv", int, &sTest, int, 1, int, 1, str)

MulDiv(x,1,1) returns x unmodified, but DllCall interprets the return value as a string.

If the string isn't null-terminated or you want only a portion of the string, you may use lstrcpyn via DllCall.

[TheGood]

MulDiv(x,1,1) returns x unmodified, but DllCall interprets the return value as a string.

Very interesting behaviour. Is that an AHK thing, or the dll itself? Is it because AHK knows it's a string pointer that was passed and not any number?

[TheGood]

Sorry, didn't see the "str" in the return type parameter

[SKAN]

sTest := "This is a test sentence."
MsgBox % DllCall("MulDiv", int, &sTest, int, 1, int, 1, str)

MulDiv(x,1,1) returns x unmodified, but DllCall interprets the return value as a string.

:shock: Thanks!