How to make function that deconcatenate an string

Hello I have to make a function that deconcatenate a string whenever a space bar appears. It has to be with mkdir, rmdir and rename also it has to be with for cycle

the example the teacher gave is on the photo.

What I understand is that when I put (mkdir Hello) this is the string I have to separate in temporal variables and that they separate when a null appears on the serial monitor it has to create the directory.

If the string is a C-string (zero terminated character array) then the string function strtok() will separate the pieces.

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The parse example in Serial Input Basics may be helpful.

The usual word is "split" rather than "deconcatenate"

...R