Usage for head:

node ./head.js -n5 file1
node ./head.js -n 5 file1
node ./head.js -5 file1
node ./head.js file1 file2
node ./head.js -n 5 file1 file2
node ./head.js -n5 file1 file2
node ./head.js -5 file1 file2 
node ./head.js -c5 file1
node ./head.js -c 5 file1
node ./head.js -c5 file1 file2
node ./head.js -c 5 file1 file2

Usage for tail:

node ./tail.js -n5 file1
node ./tail.js -n 5 file1
node ./tail.js -5 file1
node ./tail.js file1 file2
node ./tail.js -n 5 file1 file2
node ./tail.js -n5 file1 file2
node ./tail.js -5 file1 file2 
node ./tail.js -c5 file1
node ./tail.js -c 5 file1
node ./tail.js -c5 file1 file2
node ./tail.js -c 5 file1 file2