The following two activities are based on the Pipes and Filters lesson.
Ex 1. Beginning with the animals.text file from the lesson which contains the following lines:
2012-11-05,deer 2012-11-05,rabbit 2012-11-05,raccoon 2012-11-06,rabbit 2012-11-06,deer 2012-11-06,fox 2012-11-07,rabbit 2012-11-07,bear
Which of the following commands will create a new file containing only the non-deer entries sorted in descending date order?
a) grep -v deer animals.txt | sort -r > out.txt
b) grep -v deer animals.txt > sort -r | out.txt
c) grep -v deer <code>--sort -r animals.txt out.txt</code>
d) grep -v deer animals.txt | sort out.txt
**Ex 2. ** Along with animals.txt, assume that you have two additional files: minerals.txt and vegetables.txt. Like animals.txt, each line of both of these files consists of two fields, a date and a text key. Make a list containing only the text keys from all three files that are associated with the date 2012-11-05, excluding duplicate entries.