Finding Cycles in a UNIX File System

Explore how to detect cycles in UNIX file systems caused by symbolic links with a practical Go command-line utility. Learn techniques for tracking visited directories, handling symbolic links using os.Lstat and filepath functions, and ensuring safe traversal to identify loops in the system. This lesson helps you implement cycle detection to support safe file system operations.

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This lesson implements a practical UNIX command-line utility that can find cycles (loops) in UNIX file systems. The idea behind the utility is that with UNIX symbolic links, there is a possibility to create cycles in our file system. This can perplex backup software such as tar(1) or utilities such as find(1) and can create security-related issues. The presented utility, which is called FScycles.go, tries to inform us about such situations.

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The idea behind the solution is that we keep every visited directory path in a map, and if a path appears for the second time, then we have a cycle. The map is called ...

1.Course Introduction

2.Introduction to Go

3. Basic Go Data Types

4.Composite Data Types

5.Reflection and Interfaces

6.Go Packages and Functions

7.Telling a UNIX System What to Do

8.Go Concurrency

9.Building Web Services

10.Working with TCP/IP and WebSocket

11.Working with REST APIs

12.Code Testing and Profiling

13.Working with gRPC

14.Go Generics

15.Conclusion

16.Appendix A—Go Garbage Collector

Finding Cycles in a UNIX File System

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