生成随机的密码，支持长度自定义

gen_passwd.sh

#Version 1

read -p "please input the length of passwd: " p

list=(0 1 2 3 4 5 6 7 8 9 a b c d A B C D + -)

for i in $(seq $p); do
        echo -n ${list[$RANDOM % ${#list[*]}]}
done

#Version 2
read -p "please input the length of passwd: " p

list="123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ"

while [ "${n:=1}" -le "$p" ]; do
        pass="$pass${list:(($RANDOM%${#list})):1}"
        let n+=1
done
echo $pass