Power of Unix

Why I love Unix. A Lightning Talk for Teach Us Something Technical
www.meetup.com/Teach-Us-Something-Technical/events/222877398/

Transcript

1. Power of Unix
2. or Why I Love Bash
3. The Challenge Read a file of text, determine the n most frequently used words, and print out a sorted list of those words along with their frequencies.
4. The Solution(s) A): Donald Knuth’s Literary Programming 10 Pages of ‘perfect’ Pascal B): Douglas McIlroy’s 6 lines of UNIX
5. 1 tr -cs A-Za-z '\n' | 2 tr A-Z a-z | 3 sort | 4 uniq -c | 5 sort -rn | 6 head -n 1
6. tr -cs A-Za-z '\n' Turn the paragraphs into one-word lines
7. tr A-Z a-z Make all words lowercase
8. sort Sort to bring identical words together.
9. uniq -c Replace each run of duplicate words with a single representative and include a count (-c).
10. sort -rn Sort in reverse (-r) numeric (-n) order.
11. head -n 1 Take the first line ‘the’ is used 7 Times!
12. All together now cat text.txt | tr -cs A-Za-z '\n' | tr A-Z a-z | sort | uniq -c | sort -rn | head -n 1 10 Pages of Pascal in 6 lines of Unix
13. Note on Performance King James Bible: 4.2 M Text File 794,915 Words time cat bible.txt | tr -cs A-Za-z '\n' | tr A-Z a-z | sort | uniq -c | sort -rn | head -n 20 #=> real 0m11.918s Extra Credit: awk 'length($0)>4'
14. Appendix http://www.leancrew.com/all-this/2011/12/more-shell-less-egg /