A file called animals.txt
(in the shell-lesson-data/data
folder) contains the following data:
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
What text passes through each of the pipes and the final redirect in the pipeline below?
$ cat animals.txt | head -n 5 | tail -n 3 | sort -r > final.txt
Hint: build the pipeline up one command at a time to test your understanding
head
command extracts the first 5 lines from animals.txt
. Then, the last 3 lines are extracted from the previous 5 by using the tail
command. With the sort -r
command those 3 lines are sorted in reverse order and finally, the output is redirected to a file final.txt
. The content of this file can be checked by executing cat final.txt
. The file should contain the following lines:
2012-11-06,rabbit
2012-11-06,deer
2012-11-05,raccoon