Interview Questions.

Question 1. How To Print Only Blank Line Of File.?

Answer :

sed -n '/^$/p' Test_file.Txt

Question 2. Write A Command To Print First And Last Line Using Sed Command?

Answer :

sed  -n ‘1p’ Test_file.Txt

sed –n ‘$p’ Test_file.Txt

Sed (Stream Editor) Interview Questions
Question three. Write A Command To Print All Line Except First Line?

Answer :

sed –n ‘1!P’ Test_file.Txt

Question four. Write A Command Delete All Line Except First Line?

Answer :

sed –n ‘1!D’ Test_file.Txt

AWK Tutorial
Question five awk '/^-/  if($5 ==0) print $9 '

Question 6. How Add A First Record And Last Record To The Current File In Linux?

Answer :

sed -i -e '1i Header' -e '$a Trailor' test_file.Txt

Question 7. How To Display Even Number Of Records Into One File And Odd Number Of Records Into Another File?

Answer :

awk 'NR %2 == 0' test_files.Txt

awk 'NR %2 !=  0' test_files.Txt

Sed (Stream Editor) Tutorial
Question eight. Write A Command Remove All Empty Lines:

Answer :

sed '/^$/d' test_file.Txt

sed '/./!D' test_file.Txt

Question 9. How To Run Awk Command Specified In A File?

Answer :

awk -f filename

Question 10. Write A Command To Print The Squares Of Numbers From 1 To 10 Using Awk Command?

Answer :

awk 'BEGIN  for(i=1;i<=10;i++) print "square of",i,"is",i*i;'

Question 11. Write A Command To Find The Sum Of Bytes (size Of File) Of All Files In A Directory.?

Answer :

ls -l sum=0 sum = sum + $5 END print sum'

Question 12. In The Text File, Some Lines Are Delimited By Colon And Some Are Delimited By Space. Write A Command To Print The Third Field Of Each Line.?

Answer :

awk ' if( $0 ~ /:/ )  FS=":";  else  FS =" ";  print $3 ' filename

Sed (Stream Editor) Interview Questions
Question 13. Write A Command To Print The Line Number Before Each Line?

Answer :

awk 'print NR, $0' filename.

Question 14. Write A Command To Print The Second And Third Line Of A File Without Using Nr.?

Answer :

awk 'BEGIN RS="";FS="n" print $2,$3' filename

Question 15. Write A Command To Print Zero Byte Size Files?

Answer :

ls -l if ($5 !=0 ) print $9 '

Question 16. Write A Command To Rename The Files In A Directory With "_new" As Postfix?

Answer :

ls -F print "mv "$1" "$1".New"' ORS=""  for(i=NF;i>0;i--) print $i," "; print "n"' filename

Question 18. Write A Command To Find The Total Number Of Lines In A File Without Using Nr?

Answer :

awk 'BEGIN sum=zero sum=sum+1 END print sum' filename