# Take the last line of the top three lines 
head -n 3 my.txt | tail -n 1 
 
# Tell sed to "be quiet", and print just the third line 
sed -n 3p my.txt 
 
# Tell sed to delete everything except the third line 
sed '3!d' my.txt 
 
# Tell awk to print the third input record of the current file 
awk 'FNR==3 {print}' my.txt