The problem is here: https://leetcode.com/problems/tenth-line/. It's a bash programming, reading the 10th line of a file and output in stdout. I think there are lots of methods to do this, here I write some.
If the file has more than 10 lines, I can output like this:
$ head -n 10 file.txt | tail -n 1
BUT, reality is not, above command failed. Then I have the following:
i=0 while read line do i=$(($i+1)) if [ $i -eq 10 ]; then echo $line break fi done < file.txt
This time works.