【bat】判断字符串是否包含某字符串

@echo off
set a=55544333
set c=6666dfsfds
set b=44
echo %a%| findstr %b% >nul && (
    echo %a%包含%b%
) || (
    echo %a%不包含%b%
)
echo %c%| findstr %b% >nul && (
    echo %c%包含%b%
) || (
    echo %c%不包含%b%
)

pause