#Persistent
#SingleInstance, Force
CL := % A_MyDocuments "\GTA San Andreas User Files\SAMP\chatlog.txt"
Loop {
    chatline :=  GetNewLine(CL)
    if (RegExMatch(chatline, "^\[\d{2}:\d{2}:\d{2}\] Сервер закрыл соединение")) {
  Process, Close, gta_sa.exe
    }
}

GetNewLine(filename)
{
   static old
   static new
   if !old
   {
      FileGetSize, old, %filename%
      new := old
   }
   while old = new
   {
      sleep 500
      FileGetSize, new, %filename%
   }
   old := new
   Loop, read, %filename%
      if A_LoopReadLine
         last := A_LoopReadLine
   return last
}