If..then..elif

1. If..then..elif • Template: • if test-command; then • commands • elif test-command; then • commands • … • else • commands • fi

2. Day 14 Looping

3. Example • if [ “$name” = “Jeff” ]; then • echo “Hey Jeff” • elif [ “$name” = “Bob” ]; then • echo “Hey Bob” • elif [ “$name” = “Bill” ]; then • echo “Hey Bill” • else • echo “I dont know you” • fi

4. And • Test with -a • Example: • if[ “$firstname” = “Jeff” –a / • “$lastname” = “Wilson” ]; then • echo “You are my hero!” • fi

5. Or • Test with –o • Example: • if[ “$name” = “Jeff” –o / • “$name” = “Jeffrey” ]; then • echo “You are my hero!” • fi

6. Loop! • Template: • forloop-indexin argument-list • do • echo “do stuff” • done

7. Example • for fruit in apple orange pear • do • echo “$fruit” • done

8. Whoson Script • Find out which of your friends are on. • Automatically write them a greeting message.

9. While Loop • Template: • while test-command • do • commands • done

10. Example • number=0 • while [ “$number” –lt 10 ] • do • echo –n “$number” • let number=“$number”+1 • done

11. Until • Another type of loop • This one ALWAYS runs at least once

12. Until Template • until test-command • do • commands • done

13. Until Example • name=duh • echo “Guess the name!” • until [ “$name” = “bob” ] • do • echo -n “guess: “ • read name • done • echo “You got it!”

14. Break • Allows you to jump out of a loop (even if the loop isn’t finished)

15. Break Example • ans=“y” • while [ “bob” = “bob” ] • do • echo “Want to stop looping? (y or n)” • read ans • if [ $ans = “y” ]; then • break • fi • done