alert ?-w win? ?-t (critical|info|warning)? ?-k okStr? ?-c cancelStr? ?-o otherStr? ?-title titleStr? ?-index? ?--? message ?explanation?
This command will display the message string in a standard alert box. If present, the explanation string will be displayed in the small System font. The options have the following meaning:
If cancelStr or otherStr is an empty string or is not specified, the corresponding button will be omitted. There is always at least one button (it is the default button in the -k position).
By default, the command returns the name of the button that was pressed but, if the
-index option is specified, it returns the button's index (starting at 0 for the rightmost button).
If the -w option is specified, the alert is displayed in a sheet window attached to the window designated by the win argument. Otherwise, the alert is displayed as a modal dialog.