How to only read the last line from a text file

Question

I am working on a tool project. I need to grab the last line from a file & assign into a variable. This is what I have tried:

line=$(head -n $NF input_file)
echo $line

Maybe I could read the file in reverse then use

line=$(head -n $1 input_file)
echo $line

Any ideas are welcome.

Answer 1

Use tail ;)

line=$(tail -n 1 input_file)
echo $line

Answer 2

Combination of tac and awk here. Benefit in this approach could be we need NOT to read complete Input_file in it.

tac Input_file | awk '{print;exit}'

Answer 3

With sed or awk :

sed -n '$p' file
sed '$!d' file
awk 'END{print}' file

However, tail is still the right tool to do the job.