sort/uniq

The sort commands sorts the the lines of text files in order. You can use different arguments like -r to sort them in reverse order. The uniq command is used with the sort command to remove duplicate lines in the file that you are sorting. There are also arguments for uniq like -d that only prints duplicated lines or -u that only prints unique lines.

List any sites, books, or sources utilized when researching information on this topic. (Remove any filler text).

• man page for sort
• man page for uniq
• http://en.wikipedia.org/wiki/Uniq

cron/crontab/at

      Is the time-based job scheduler in Unix-like computer operating systems. 
      Enables users to schedule jobs (commands or shell scripts) to run periodically
       at certain times or dates. 
      It is commonly used to automate system maintenance or administration.
      
      __Crontab_ (cron table) file, a configuration file that specifies shell 
      commands to run periodically on a given schedule. 
      

• Wikipedia
• Sean Edwards
• Harley Hahn's Guide to Unix and Linux

Demonstration of the indicated keyword.

lab46:~$ at 16:08 
warning: commands will be executed using /bin/sh
at> echo "hi"
at> <EOT>
job 319 at Fri Nov 30 16:08:00 2012
lab46:~$ at -l
319	Fri Nov 30 16:08:00 2012 a mwitter3