First link:https://www.chegg.com/homework-help/questions-and-answers/bash-scripting-exam-cis440-unix-1-factorial-problem-create-script-prompts-user-integer-out-q33998523
Second link:https://www.chegg.com/homework-help/questions-and-answers/cis440-unix-project-write-non-inte-ractive-script-called-createnewuserssh-parses-name-pass-q42536301