AutoHotkey Community

Tail(k,file)   ; Return the last k lines of file
{
   Loop Read, %file%
   {
      i := Mod(A_Index,k)
      L%i% = %A_LoopReadLine%
   }
   L := L%i%
   Loop % k-1
   {
      IfLess i,1, SetEnv i,%k%
      i--      ; Mod does not work here
      L := L%i% "`n" L
   }
   Return L
}

MsgBox % Tail(3, A_ScriptFullPath)

Loop Read, %A_ScriptFullPath%
   L = %A_LoopReadLine%

Tail(k,file)   ; Return the last k lines of file
{
   FileRead text, %file%
   Loop Parse, text, `n
     lines++
   Loop Parse, text, `n
   {
      If (A_Index < lines - k)
         Continue
      L = %L%`n%A_Loopfield%
   }
   StringTrimLeft L, L, 1
   Return L
}

#Persistent
Settimer FileCheck

FileCheck:
   FileGetSize Size, %A_ScriptFullPath%   ; put your filename here
   If Size0 >= %Size%
      Return
   If Size0 =
   {
      Size0 = %Size%
      Return
   }
   MsgBox File size increased!
   Size0 = %Size%
Return

str_getTailf(ByRef _Str) {
    Return SubStr(_Str,InStr(_Str,"`n",False,0)+1)
}

str_getTail(_Str, _LineNum = 1)
{
    StringGetPos, Pos, _Str, `n, R%_LineNum%
    StringTrimLeft, _Str, _Str, % ++Pos
    Return _Str
}

Text := "`n`n`n"
Loop, 100000
    Text .= "`nLine " . A_Index

StartTime := A_TickCount
Loop, 100
str_getTailf(Text)
ElapsedTime1 := A_TickCount - StartTime

StartTime := A_TickCount
Loop, 100
str_getTail(Text)
ElapsedTime2 := A_TickCount - StartTime

StartTime := A_TickCount
Loop, 100
StrTail(1,Text)
ElapsedTime3 := A_TickCount - StartTime

StartTime := A_TickCount
Loop, 100
Tail(1,Text)
ElapsedTime4 := A_TickCount - StartTime

out =
(
str_getTailf (by Tuncay):`t`t%ElapsedTime1%
str_getTail (by Tuncay):`t`t%ElapsedTime2%
StrTail /loop (by strictlyfocused02):`t%ElapsedTime3%
Tail /regex (by Laszlo):`t`t%ElapsedTime4%
)
MsgBox, 1, Benchmark results, Ok copies to clipboard`n`n%out%
IfMsgBox Ok
    Clipboard := out

RETURN

str_getTailf(ByRef _Str) {
    Return SubStr(_Str,InStr(_Str,"`n",False,0)+1)
}

str_getTail(_Str, _LineNum = 1)
{
    StringGetPos, Pos, _Str, `n, R%_LineNum%
    StringTrimLeft, _Str, _Str, % ++Pos
    Return _Str
}

StrTail(k,str) ;; Inspired by Laszlo (http://www.autohotkey.com/forum/topic6928.html)
   {
   Loop,Parse,str,`n
      {
      i := Mod(A_Index,k)
      L%i% = %A_LoopField%
      }
   L := L%i%
   Loop,% k-1
      {
      If i < 1
         SetEnv,i,%k%
      i-- ;Mod does not work here
      L := L%i% "`n" L
      }
   Return L
   }

Tail(k,str) {
      Return RegExReplace(str,".*(?=(\n[^\n]*){" k "}$)")
}

Text =
(
Text of Line 1
Text of Line 2
Text of Line 3
Text of Line 4
Text of Line 5
Text of Line 6
Text of Line 7
Text of Line 8
Text of Line 9
Text of Line 10
Text of Line 11
Text of Line 12
Text of Line 13
Text of Line 14
Text of Line 15
)

MsgBox,% StrTail(4,Text)

;Return the last (k) lines of (str)
StrTail(k,str) ;; Inspired by Laszlo (http://www.autohotkey.com/forum/topic6928.html)
   {
   Loop,Parse,str,`n
      {
      i := Mod(A_Index,k)
      L%i% = %A_LoopField%
      }
   L := L%i%
   Loop,% k-1
      {
      If i < 1
         SetEnv,i,%k%
      i-- ;Mod does not work here
      L := L%i% "`n" L
      }
   Return L
   }

MyVar := StrTail(4,Text)

Tail(k,file) {  ; Return the last k lines of file
   Loop Read, %file%
      i := Mod(A_Index,k), L%i% := A_LoopReadLine
   Loop % k
      i := Mod(i+1,k), L .= L%i% "`n"
   Return L
}

fileGetLastLines(varFilename,varLines=1) {
   linecount:=0
   file:=FileOpen(varFilename, "r")
   if (not file)
      return 0
   Loop {
      file.Seek(0-A_Index, 2)
      line:=file.Read(1)
      if ((RegExMatch(line,"`n") or RegExMatch(line,"`r")) and not File.AtEOF)
         linecount++
   } until ((RegExMatch(line,"`n") or RegExMatch(line,"`r")) and not File.AtEOF and linecount=varLines)
   Loop {
      output.=file.Readline()
   } until (File.AtEOF)
   file.Close()
   return output
}