Functionality:
- make directory - mkdir nameOfFolder
- traverse directory - ls depth
- comparing files - cmp absolutePath1 absolutePath2
- change directory - cdRel relativePath or ".." for level up
- change directory - cdAbs absolutePath
- read students database - readDb fileName
- filter students from some course by given filter and add quantity for the number of students to take, or all, if you want to take all the students matching the current filter - filter {courseName} excellent/average/poor take 2/5/all
- order student from given course by ascending or descending order and then taking some quantity of the filter, or all that match it - order {courseName} ascending/descending take 20/10/all
- download file - download URL (saved in current directory)
- display data entities - display students/courses ascending/descending
- open – open file
- get help – help