AutoIt operates in one of four "Window matching" modes. The modes are set with the AutoItSetOption function using the WinTitleMatchMode option.
Mode 1 (default)
Matches partial titles from the start.
In this mode the a window titled Untitled - Notepad would be matched by "Untitled - Notepad", "Untitled", "Un", etc.
eg.
WinWait("Untitled")
Mode 2
Matches any substring in the title.
In this mode a window titled Untitled - Notepad would be matched by "Untitled - Notepad", "Untitled", "Notepad", "pad", etc.
eg.
WinWait("Notepad")
Mode 3
Exact title match.
In this mode a window titled Untitled - Notepad would only be matched by "Untitled - Notepad"
Mode 4
Advanced mode.
In this mode special sequences are used in the title parameter so that window classnames and handles can be used. The text parameter remains the same.
The special sequences must contain no whitespace. They are:
"classname=CLASSNAME"
"active"
"last" or ""
"classname=" matches a window based on its classname. For example to identify a window that has the classname "MYCLASS1" then you would use "classname=MYCLASS1" for the title parameter.
"active" matches the currently active window (same as ""
in the default WinTitleMatchMode).
"last" uses the last successful window match so you don't have to
keep specifying the title and text again and again. e.g.
AutoItSetOption("WinTitleMatchMode", 4)
WinWaitActive("Untitled - Notepad")
WinClose("last") ; Closes the previously matched notepad window
Note: If "classname=", "active",
"last" or "" are not used as the title then the window matching
takes place as in Mode 1 making this a good mode for general
use.
The variant datatype in AutoIt natively supports window handles (HWNDs). A window handle is a special value that windows assigns to a window each time it is created. When you have a handle you may use it in place of the title parameter in any of the function calls that use the title/text convention. The advantage of using window handles is that if you have multiple copies of an application open - which have the same title/text - you can uniquely identify them when using handles. When you use a window handle for the title parameter then the text parameter is completely ignored.
Various functions such as WinGetHandle, WinList and GUICreate return these handles. It is important to note that a window handle is not classed as a number or string - it is it's own special type.
Note: Window handles will work no matter what WinTitleMatchMode is currently in use.
Example
$handle = WinGetHandle("Untitled - Notepad", "")
WinClose($handle)