Learning Java by building Core Utils

cat command

Simple and uses the io package instead of nio. I chose io becuase it is used for smalled applications and nio is more for larger files.

grep command

Basic form of grep, can search for a word or list of words in a file.

head+tail command

Prints the first 10 or last 10 lines of a plain text file.

ls command

List each item in a directory line by line.

mkdir command

Creates directories where you ask.

sort command

Sort items provided as arguments.

spellChecker command

Linux only, but uses the words file to check if words as arguments are spelled correctly.

Apparenly not possible as far as I can see.

cd command

I was working on this one, till I realized there isn't a way to change the working directory after the program has ended. If there is a way, I wasn't able to find it.