问在索引处插入一个字符串并检查它是否在01-12范围内.如何在外壳中实现？

EN

printf '%s\n' 20221201 | awk '
    {match($0, /^[0-9]{4}([0-9]{2})[0-9]{2}/, a)
    if (a[1] > 0 && a[1] <= 12) {print a[1] " in range"}
    else{print a[1] " not in range"}}'

printf '%s\n' 20221201 |
    awk '(length($0) != 8 || ! match($0, /^[0-9]{4}[0-9]{2}[0-9]{2}/))
    {print "wrong input"; exit}
    var = substr($0, 5, 2)
    if (var > 0 && var <= 12) {print var " in range"}
    else{print var " not in range"}}'

printf '%s\n' 20221201 |
    perl -nE 'my $m = $1 if /^\d{4}(\d{2})\d{2}/;
    if ($m > 0 && $m <= 12) { say "$m in range" } else {say "$m not in range"}'

bDate=20221201
[[ $bDate =~ ^[0-9]{4}([0-9]{2})[0-9]{2} ]] || { echo "wrong input"; exit; }
if ((${BASH_REMATCH[1]} > 0 && ${BASH_REMATCH[1]} <=12)); then
    echo "${BASH_REMATCH[1]} in range"
else
    echo "${BASH_REMATCH[1]} not in range"
fi