this is my answer for FSA class on a Node unix shell.

related solution video is https://www.youtube.com/watch?v=v_lhkZ849jk

node bash to run

#valid commands:

• 'pwd'
• 'date'
• 'ls'
• 'echo'
• 'cat'
• 'head'
• 'tail'
• 'wc'
• 'uniq'
• 'sort'
• 'curl'
• 'grep