Leerzeichen am Anfang und Ende löschen

@echo off &setlocal DisableDelayedExpansion
::Linefeed
set ^"LF=^  

^" EMPTY LINE ABOVE IS CRITICAL!  
set ^"\n=^^^%LF%%LF%^%LF%%LF%^^"  

::%$TRIM% strVar [charVar] -- macro for trimming both left and right
set $Trim=for /l %%I in (1 1 2) do if %%I==2 (%\n%
  set "_spcs= "%\n%  
  for /f "tokens=1,2" %%J in ("!_arg!") do (%\n%  
    set "_str=!%%J!"%\n%  
    if "%%~K" neq "" if defined %%~K set "_spcs=!%%K:~0,1!"%\n%  
    for /l %%i in (1 1 12) do set "_spcs=!_spcs!!_spcs!"%\n%  
    set /a "k=4096"%\n%  
    for /l %%j in (1 1 13) do (%\n%
      if defined _str for %%k in (!k!) do (%\n%
        if "!_str:~-%%k!"=="!_spcs:~-%%k!" set "_str=!_str:~0,-%%k!"%\n%  
        if "!_str:~0,%%k!"=="!_spcs:~-%%k!" set "_str=!_str:~%%k!"%\n%  
        set /a "k/=2"%\n%  
      )%\n%
    )%\n%
    if defined _str (%\n%
      if not defined _notDelayed (%\n%
        set "_str=!_str:^=^^!"%\n%  
        set "_str=!_str:"=""Q!^"%\n%  
        call set "_str=%%^_str:^!=""E^!%%" ! %\n%  
        set "_str=!_str:""E=^!"%\n%  
        set "_str=!_str:""Q="!^"%\n%  
      )%\n%
      for /f ^^^"eol^^=^^^%LF%%LF%^%LF%%LF%^^ delims^^=^^^" %%k in ("!_str!") do endlocal^&endlocal^&set "%%J=%%k"!%\n%  
    ) else endlocal^&endlocal^&set "%%J="%\n%  
  )%\n%
) else setlocal^&set "_notDelayed=!"^&setlocal EnableDelayedExpansion^&set _arg=  

:::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::

for /f "delims=" %%i in ('type "datei.txt"^|findstr /n "^"') do (  
  set "ln=%%i"  
  setlocal EnableDelayedExpansion
  set "ln=!ln:*:=!"  
  %$TRIM% ln
  echo(!ln!
  endlocal
)
pause

@echo off
for /f "usebackq delims=" %%i in ("d:\temp\bsp.txt") do call :trimthis %%i  
pause
goto :eof

:trimThis
echo [%*]
goto :eof