“at” utility in unix is similar to the “cron” daemon except for that “at” jobs are run only once while cron jobs are recurring. “at” is primarily used to schedule a job which can be command or a script to run once at a particular time although it can be made to reschedule the job. This could be immediatly or at a later time. The at utility reads commands from standard input and groups them together as an at job, to be executed at a later time. How to Create an at Job: Start the at utility, specifying the time you want your job executed. $ at [-m] time [date] "-m" Sends you email after the job is completed. time Specifies the hour that you want to schedule the job. Add am or pm if you do not specify the hours according to the 24-hour clock. Acceptable keywords are midnight , noon , and now . Minutes are optional. date Specifies the first three or more letters of a month, a day of the week, or the keywords today or tomorrow . At the at prompt, type...