@echo off
setlocal enabledelayedexpansion
title by TAT v1.0
set /p str=
set /A len=0
for /L %%i in (0,0,0) do (
	set /A len=!len!+1
echo !str!	!str:~-1!
	if /I !str! EQU !str:~-1! (
			echo 此字符串长度为len=!len!
			pause>nul & exit
			) 
	set str=!str:~-0,-1!
)

rem 已知bug如下：
rem 1.直接不输入回车会出值。
rem 2.0开头的话会出错
rem 3.汉字按一个长度算，程序算出的其实是字符个数。
rem 4.cmd单次输入字符最多1021个。。
复制代码

@echo off
setlocal enabledelayedexpansion
:GetInput
set "str="
set /p "str=请输入字符串："
if "x!str!" equ "x" (
    goto :GetInput
)
set "len=0"
for /l %%i in (0,0,0) do (
    set /a len=!len!+1
    echo !str!	!str:~-1!
    if /i "!str!" equ "!str:~-1!" (
        echo 此字符串长度为len=!len!
        pause
        exit
    )
    set "str=!str:~-0,-1!"
)
复制代码