To employ your growing shell script abilities in calculating a user's time spent online (on lab46) for the semester.

I would like you to write a script that:

• accepts a user:
  • via command-line
  • via input (if there is nothing on the command-line, prompt the user to enter one)
• verifies provided user is a valid user
  • in the case of an invalid user, display an error message and exit
• calculates the time on-line for said user for the months of August, September, October, November, and December.
  • be sure these values are displayed somewhere in the script's output (both broken out by month, and total for semester)
  • determine total resulting time in days, hours, and minutes.
• display data in the form of a histogram, with one line per month, visualizing the number of logins
  • you may scale it accordingly to better fit on a standard size terminal
  • be sure to show the total number of logins for that month

Example output may look something like:

lab46:~/src/unix/timeonline$ ./timeonline jbob
error: no such user 'jbob' exiting ...
lab46:~/src/unix/timeonline$ ./timeonline jsmith12
Aug|**** (37)
Sep|****** (61)
Oct|******* (73)
Nov|******* (74)
Dec|** (17)

Aug: 0 days, 14 hours, 31 minutes
Sep: 2 days, 3 hours, 17 minutes
Oct: 2 days, 5 hours, 58 minutes
Nov: 3 days, 1 hour, 47 minutes
Dec: 0 days, 5 hours, 32 minutes

Total: 8 days, 7 hours, 5 minutes

Submission criteria are as follows:

• Script is organized and easy to read
• Indentation to enhance readability
• Comments to explain what is going on
• Submit on time!
• submit using submit tool, project name timeonline