Design an object-oriented module that mimics the UNIX 'find' command to search the filesystem by criteria. Requirements: support filtering by name pattern (glob/regex), file type (file/dir/link), size ranges, modification/creation time, permissions/owner, and depth limits; allow composing predicates with AND/OR/NOT; provide options for following or skipping symlinks; and support outputting paths or file metadata. Propose APIs for command-style and library usage, show how to extend with new filters, discuss traversal and performance (early pruning, concurrency), and address robustness for large directories and permission errors. Provide class diagrams or interfaces, key data structures, and test cases.

This question evaluates object-oriented and API design skills, filesystem semantics (pattern matching, file types, timestamps, permissions, symlink handling), traversal and concurrency strategies, and robustness for large or error-prone directory trees.

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Design a file search module like UNIX find

Design Task: Object-Oriented module that mimics UNIX find

Context

Design an object-oriented library that replicates the core functionality of the UNIX find command for searching a filesystem by various criteria. The module should be usable as a library and also expose a command-style fluent API for easy composition.

Functional Requirements

Filters
- Name pattern: glob and regex
- File type: file, directory, symlink
- Size ranges: e.g., >10 MB, between 1–5 KB
- Times: modification time (mtime), creation/birth time (if available), change time (ctime)
- Permissions/owner/group
- Depth limits: maxDepth, minDepth
Predicate composition: AND, OR, NOT
Symlink handling: options to follow or skip symlinks; prevent cycles
Outputs: emit path strings and/or structured file metadata

Non-Functional Requirements

Traversal and performance
- Early pruning of subtrees when possible (depth/type/name pre-checks)
- Optional concurrency: parallel directory traversal with backpressure
- Efficient directory iteration and stat calls
Robustness
- Handle very large directories and deep trees without recursion overflow
- Graceful handling of permission errors, races (file disappears), broken symlinks
- Cancellation and timeouts

Deliverables

Proposed APIs
- Command-style fluent builder
- Library-style iterator/stream API
Extensibility: how to add new filters/predicates
Traversal algorithm and performance considerations
Robustness/error-handling strategy
Class diagrams or interfaces and key data structures
Representative test cases

Functional Requirements

Filters

Name pattern: glob and regex
File type: file, directory, symlink
Size ranges: e.g., >10 MB, between 1–5 KB
Times: modification time (mtime), creation/birth time (if available), change time (ctime)
Permissions/owner/group
Depth limits: maxDepth, minDepth

Predicate composition: AND, OR, NOT

Symlink handling: options to follow or skip symlinks; prevent cycles

Outputs: emit path strings and/or structured file metadata

Non-Functional Requirements

Traversal and performance

Early pruning of subtrees when possible (depth/type/name pre-checks)
Optional concurrency: parallel directory traversal with backpressure
Efficient directory iteration and stat calls

Robustness

Handle very large directories and deep trees without recursion overflow
Graceful handling of permission errors, races (file disappears), broken symlinks
Cancellation and timeouts

Deliverables

Proposed APIs

Command-style fluent builder
Library-style iterator/stream API

Extensibility: how to add new filters/predicates

Traversal algorithm and performance considerations

Robustness/error-handling strategy

Class diagrams or interfaces and key data structures

Representative test cases

Design a file search module like UNIX find

Quick Overview

Design Task: Object-Oriented module that mimics UNIX find

Context

Functional Requirements

Non-Functional Requirements

Deliverables

Solution

Comments (0)

Design a file search module like UNIX find

Quick Overview

Design Task: Object-Oriented module that mimics UNIX find

Context

Functional Requirements

Non-Functional Requirements

Deliverables

Solution

Comments (0)