tenth-line.sh

# Time:  O(n)
# Space: O(1)
#
# How would you print just the 10th line of a file?
#
# For example, assume that file.txt has the following content:
# 
# Line 1
# Line 2
# Line 3
# Line 4
# Line 5
# Line 6
# Line 7
# Line 8
# Line 9
# Line 10
# Your script should output the tenth line, which is:
# Line 10
#
# Hint:
# 1. If the file contains less than 10 lines, what should you output?
# 2. There's at least three different solutions. Try to explore all possibilities.
#
# Read from the file file.txt and output the tenth line to stdout.

# Solution 1
awk '{if(NR==10) print $0}' file.txt
awk 'NR == 10' file.txt

# Solution 2
sed -n 10p file.txt

# Solution 3
tail -n+10 file.txt | head -1