1. Create a Linux system account and password through location variables
2. Real-time monitoring of the machine's memory and the remaining space of the hard disk. When the remaining memory is less than 500M, and the remaining space of the root partition is less than 1000M, a prompt will be given
3. The script generates a random number within 100 and prompts the user to guess the number. According to the user's input, the user is prompted to guess the right, guess the small or guess the big, until the user guesses the right script.
4. Check whether the current user of the machine is a super administrator, if it is an administrator, use yum to install vsftpd, if not, then prompt you to be a non-administrator (use string to compare versions)
5. Detect whether the current user of the machine is a super administrator, if it is an administrator, use yum to install vsftpd, if not, then prompt you to be a non-administrator (use UID digital comparison version)
