Technical Interview - File System

Problem Statement

Create functions and data structure that can mimic Linux file system commands:

• ls
• mkdir
• readFile
• appendToFile

Assumptions:

• All functions are using full path
• File content is only String

Considerations

Exceptions:

• File not found
• Directory not found
• File cannot be opened
• Directory is a file
• Empty path
• Not enough permission

Class Structure

Patterns:

• Abstract factory (Filesystem)
• Command (FilesystemCommand)

Class diagram:

Utility functions:

• String[] splitPath(String fullPath)
• String isValidPath(String fullPath)

Reasoning for interfaces:

• Directory - there are other types of directory, such as symlinked directory, network directory, etc
• Files - there are different type of file, such as sockets
• Filesystem - abstract factory will separate concrete types of directory and file from the command, allowing for more extensibility and maintainability