Please write a shell script called greeting that displays a greeting message Hello, with the current date in the format yyyy-mm-dd and the list of the users who logged on the system on Feb. 17, 2020. Please provide a title as The users who were on the system on Feb. 17: as the last piece of the information in your greeting message;

Please write a shell script called diskusage that displays the information about the disk usage with the current date, your home directory, the disk usage by your home directory, and the capacity of the free space available on the system (at the mount point /). The four pieces of the information should be displayed in separated lines;

step by steps please