List unique species

Go to the folder exercise-data/:

Leah has several hundred data files, each of which is formatted like this:

2013 - 11 - 05, deer, 5;
2013 - 11 - 05, rabbit, 22;
2013 - 11 - 05, raccoon, 7;
2013 - 11 - 06, rabbit, 19;
2013 - 11 - 06, deer, 2;
2013 - 11 - 06, fox, 1;
2013 - 11 - 07, rabbit, 18;
2013 - 11 - 07, bear, 1;

An example of this type of file is given in animal-counts/animals.csv.

We can use the command cut -d , -f 2 animal-counts/animals.csv | sort | uniq to produce the unique species in animals.csv. In order to avoid having to type out this series of commands every time, a scientist may choose to write a shell script instead.

Write a shell script called species.sh that takes any number of filenames as command-line arguments and uses a variation of the above command to print a list of the unique species appearing in each of those files separately.

• Script species.sh exists
• The output file unique.txt exists: bash species.sh animal-counts/animals.csv > unique.txt
• The file unique.txt contains each file's unique species