tireless

@echo off
set max=0
for /f "tokens=*" %%a in (a.txt) do (
  if "%%a" neq "" call :ready "%%a"
)
echo 第 %strline% 行字数最多，共 %max% 个字符:&echo.&echo %str%&echo.
pause & exit /b
 
:ready
set var=%~1
set var=%var: =%
set /a n=0,line+=1
 
:lp
set fifteen=%var:~,15%fedcba987654321
set /a n+=0x%fifteen:~15,1%
if "%var:~15%" neq "" set "var=%var:~15%" & goto lp
if %n% gtr %max% set /a "max=n,strline=line" & set str=%~1COPY