@echo off & Setlocal EnableDelayedExpansion
set n=0
::本以为变量不定义，用时值就自动是零，这里不定义n，后面就会出错。
For /f "delims=" %%i in (a.txt) do (
	Set "a=%%i"
	Set a1=!a: =!
	Set str=0
	Call :hello
)
echo %max%
pause 
Goto :eof
:hello
If Not "!a1:~%str%,1!"=="" Set /a str+=1 & Goto hello
::此句用来计算字符串长度
If %str% gtr %n% Set n=%str%&Set max=%a%
Goto :eofCOPY

@echo off&setlocal enabledelayedexpansion
set "tmp= 0 9 8 7 6 5 4 3 2 1"
for /l %%a in (0 1 4) do set var=!tmp: =%%a!!var!
for /f "delims=" %%a in (a.txt) do (
	set str=%%a
	set m=!str: =!!str: =!!var!
	if "1!m:~100,2!" gtr "1!max!" (
		set max=!m:~100,2!
		set text=%%a
	)
)
echo !text!
pauseCOPY

@echo off&setlocal enabledelayedexpansion
for /l %%a in (1 1 5) do set a=!a!0987654321
for /l %%a in (0 1 4) do set b=%%a%%a%%a%%a%%a%%a%%a%%a%%a%%a!b!
for /f "delims=" %%a in (a.txt) do (
	set str=%%a
	set m=!str: =!!a!
	set n=!str: =!!b!
	if "1!n:~50,1!!m:~50,1!" gtr "1!max!" (
		set max=!n:~50,1!!m:~50,1!
		set text=%%a
	)
)
echo !text!
pauseCOPY

set m=0
      call :1                  
) 
echo %wang%
pause 
goto :eof 
:1
  if not "!ke1:~%m%,1!"=="" set /a m+=1&goto 1
  if %m% gtr %n% set n=%m%&set wang=%ke%
  goto :eofCOPY

gawk "{str=$0;gsub(/ /,\"\",str);count=length(str);if(max<count){max=count;strOut=$0;}}END{print strOut}" test.txtCOPY

@echo off&setlocal enabledelayedexpansion
for /f "tokens=1,2 delims=:" %%a in ('findstr /n . a.txt') do (
    set str=%%b
    set str=!str: =!
    for /l %%c in (0,1,100) do (
        set str2=!str:~%%c,1!
        if not "!str2!"=="" set /a "#%%a+=1"&set "_%%a=%%b"
 )
)
for /f "tokens=1,2 delims==" %%a in ('set #') do set num=!num! %%b
set num=!num:~1!
for /l %%a in (1,1,100) do (
    for %%b in (!num!) do (
	if %%a==%%b set shuzi=%%b
 )
)
for /f "tokens=1,2 delims==" %%a in ('set #') do (
	set zimu=%%a
	if %%b==!shuzi! set zimu=!zimu:~1!
)
call,echo;%%_!zimu!%%
pauseCOPY

@echo off&setlocal enabledelayedexpansion
set w=0&set "e="
 
for /f "tokens=*" %%i in (a.txt) do (set q=%%i
  call :m !q: =!
  set/a r=w-l
if "!r:~0,1!"=="-" (set w=!l!&set e=%%i))
echo;%e%
pause&exit
 
:m
set m=%1&set l=0
for /l %%i in (0,1,1024) do (if "!m:~%%i,1!"=="" (set/a l=%%i-1&goto :eof))COPY

"""
python3
找出字符数最多的行
2016年5月2日 03:56:13 codegay
"""
with open("a.txt") as f:
    kv={''.join(r.split()).__len__():r for r in f}
    print(kv[max(kv)])
            
            COPY

@echo off
set firstline=true
set m=0
setlocal enabledelayedexpansion
for /f "delims=" %%a in (test2.txt) do (
    set "str1=%%a"
    set "str2=!str1: =!
    if "%firstline%"=="true" (
        set firstline=false
        call :o
    ) else (
        for %%b in ("!m!") do if not "!str2:~%%b!"=="" call :o
    )
)
echo %longestline%
echo %m%
pause
goto :eof
:o
if not "!str2:~%m%!"=="" set /a m+=1&set longestline=%str1%&goto :o
goto :eofCOPY