1. grep | sed | awk | xargs | etc Practical *nix utilities(for text processing)

2. whoami

3. / awk cat grep tac sed echo ls du test mv split tail dir join wc head vim tr sort sum cut expr uniq paste kill tee

4. / Log Mega App Files DB

5. pwd | ls | find | tee GNU Coreutils http://www.gnu.org/software/coreutils/ The takeaway command:man > info coreutils

6. pwd | ls | find | tee List of files: ls –l ls–1 ls –latr find . –name *.txt

7. pwd | ls | find | tee Seek for a string in a file: grep“cat” file.txt grep –v “dog” file.txt grep –i “PaTtErN” file.txt egrep“cat|dog” file.txt zgrep“cat” file.txt.gz

8. for / xargs Do something with each file: for file in `find . –name *tmp` do rm$file done find . –name *tmp| xargsrm

9. pwd | ls | find | tee find + grep find . -name '*txt' -exec grep-l aaa{} find . -name '*txt' | xargsgrep-l aaa

10. pwd | ls | find | tee cat grep tac echo ls du test mv split tail dir join wc head tr sort sum cut expr uniq paste kill tee

11. paste

12. join

13. sort | uniq

14. wc

15. cut

16. csplit

17. awk sed

18. sed sfor substitution sed‘s/cat/dog/’ # cat -> dog sed ‘s/ab//’ # ab-> ba

19. sed pfor printing sed –n ‘/dog/p’ # print lines that match ‘dog’ sed–n ‘/start/,/end/p’ # print range

20. sed dto delete sed ‘/dog/d’ # delete lines that match ‘dog’ sed ‘1,/pattern/d’ # delete range

21. sed | and –e for invocation sed ‘s/a/A/’ | sed ‘s/b/B/’ # sed –e ‘s/a/A/’ –e ‘s/b/B/’ #

22. sed { .. } to group the commands sed ‘/pattern/ { s/p/P/ s/e/E/ }’ #pattern -> PattErn

23. sed rto read a file sed ‘/include/ r file.txt’ # insert file.txt after include wto write to a file sed‘/pattern/ w file.txt’ # write matched lines to a file

24. sedtris

25. awk aaabbb ccc aaabbbzzz awk '/zzz/' 1.txt grepzzz 1.txt aaabbbzzz

26. awk awk 'BEGIN{<initializations>} <pattern 1> {<actions>} <pattern 2> {<actions>} ... END{<final actions>}'

27. awk awk 'BEGIN{a=0, b=0} /aaa/{a++} /bbb/ {b++} END{printf “%d%d”,a,b}'

28. awk awk '{arr[$2]+=$1} END { for (id in arr) printf "%s%d",id,arr[id]}'

29. exit @antonarhipov