Curriculum Goal

After the full series you can read, design, test, review and harden Bash scripts. You know the limits of shell scripts and can decide when Python, Go or a specialized tool is a better fit.

Teaching Model

The workshop follows a repeating cycle:

Understand -> Write -> Test -> Debug -> Harden -> Document

Level Structure

Roles and Learning Paths

• Developers focus on CLI behavior, tests, CI and maintainability.
• Administrators focus on filesystems, processes, cron, systemd and recovery.
• DevOps and SRE roles focus on idempotence, observability, runners and safe automation.
• Security engineers focus on injection, secrets, permissions, PATH and auditability.

Lab Strategy

All labs run locally without production credentials. Each example creates a work/ directory, writes evidence files and can be repeated. Destructive operations are simulated or guarded by dry-run behavior.

Assessment Rubric

Sources and References

• GNU Bash Manual
• Bash Reference Manual PDF
• POSIX Shell Command Language
• bash(1) Linux man page
• GNU Coreutils Manual
• GNU grep Manual
• GNU sed Manual
• GNU gawk Manual
• ShellCheck
• Bats Core Documentation

Review Checklist for Curriculum

• 01. name the shebang and target shell explicitly: Record the affected file, command, exit code and risk.
• 02. quote variable expansions unless word splitting is deliberate: Record the affected file, command, exit code and risk.
• 03. validate inputs before they influence filenames, options or commands: Record the affected file, command, exit code and risk.
• 04. evaluate and document exit codes explicitly: Record the affected file, command, exit code and risk.
• 05. separate stderr and stdout: Record the affected file, command, exit code and risk.
• 06. create temporary files with mktemp: Record the affected file, command, exit code and risk.
• 07. test cleanup through trap: Record the affected file, command, exit code and risk.
• 08. guard destructive operations with dry-run, scope checks and confirmation: Record the affected file, command, exit code and risk.
• 09. never print or commit secrets: Record the affected file, command, exit code and risk.
• 10. check PATH and external dependencies: Record the affected file, command, exit code and risk.
• 11. handle ShellCheck warnings or suppress them with a reason: Record the affected file, command, exit code and risk.
• 12. document portability assumptions between Bash and POSIX sh: Record the affected file, command, exit code and risk.
• 13. name the shebang and target shell explicitly: Record the affected file, command, exit code and risk.
• 14. quote variable expansions unless word splitting is deliberate: Record the affected file, command, exit code and risk.
• 15. validate inputs before they influence filenames, options or commands: Record the affected file, command, exit code and risk.
• 16. evaluate and document exit codes explicitly: Record the affected file, command, exit code and risk.
• 17. separate stderr and stdout: Record the affected file, command, exit code and risk.
• 18. create temporary files with mktemp: Record the affected file, command, exit code and risk.
• 19. test cleanup through trap: Record the affected file, command, exit code and risk.
• 20. guard destructive operations with dry-run, scope checks and confirmation: Record the affected file, command, exit code and risk.
• 21. never print or commit secrets: Record the affected file, command, exit code and risk.
• 22. check PATH and external dependencies: Record the affected file, command, exit code and risk.
• 23. handle ShellCheck warnings or suppress them with a reason: Record the affected file, command, exit code and risk.
• 24. document portability assumptions between Bash and POSIX sh: Record the affected file, command, exit code and risk.
• 25. name the shebang and target shell explicitly: Record the affected file, command, exit code and risk.
• 26. quote variable expansions unless word splitting is deliberate: Record the affected file, command, exit code and risk.
• 27. validate inputs before they influence filenames, options or commands: Record the affected file, command, exit code and risk.
• 28. evaluate and document exit codes explicitly: Record the affected file, command, exit code and risk.
• 29. separate stderr and stdout: Record the affected file, command, exit code and risk.
• 30. create temporary files with mktemp: Record the affected file, command, exit code and risk.
• 31. test cleanup through trap: Record the affected file, command, exit code and risk.
• 32. guard destructive operations with dry-run, scope checks and confirmation: Record the affected file, command, exit code and risk.
• 33. never print or commit secrets: Record the affected file, command, exit code and risk.
• 34. check PATH and external dependencies: Record the affected file, command, exit code and risk.
• 35. handle ShellCheck warnings or suppress them with a reason: Record the affected file, command, exit code and risk.
• 36. document portability assumptions between Bash and POSIX sh: Record the affected file, command, exit code and risk.
• 37. name the shebang and target shell explicitly: Record the affected file, command, exit code and risk.
• 38. quote variable expansions unless word splitting is deliberate: Record the affected file, command, exit code and risk.
• 39. validate inputs before they influence filenames, options or commands: Record the affected file, command, exit code and risk.
• 40. evaluate and document exit codes explicitly: Record the affected file, command, exit code and risk.
• 41. separate stderr and stdout: Record the affected file, command, exit code and risk.
• 42. create temporary files with mktemp: Record the affected file, command, exit code and risk.
• 43. test cleanup through trap: Record the affected file, command, exit code and risk.
• 44. guard destructive operations with dry-run, scope checks and confirmation: Record the affected file, command, exit code and risk.
• 45. never print or commit secrets: Record the affected file, command, exit code and risk.
• 46. check PATH and external dependencies: Record the affected file, command, exit code and risk.
• 47. handle ShellCheck warnings or suppress them with a reason: Record the affected file, command, exit code and risk.
• 48. document portability assumptions between Bash and POSIX sh: Record the affected file, command, exit code and risk.
• 49. name the shebang and target shell explicitly: Record the affected file, command, exit code and risk.
• 50. quote variable expansions unless word splitting is deliberate: Record the affected file, command, exit code and risk.
• 51. validate inputs before they influence filenames, options or commands: Record the affected file, command, exit code and risk.
• 52. evaluate and document exit codes explicitly: Record the affected file, command, exit code and risk.
• 53. separate stderr and stdout: Record the affected file, command, exit code and risk.
• 54. create temporary files with mktemp: Record the affected file, command, exit code and risk.
• 55. test cleanup through trap: Record the affected file, command, exit code and risk.
• 56. guard destructive operations with dry-run, scope checks and confirmation: Record the affected file, command, exit code and risk.
• 57. never print or commit secrets: Record the affected file, command, exit code and risk.
• 58. check PATH and external dependencies: Record the affected file, command, exit code and risk.
• 59. handle ShellCheck warnings or suppress them with a reason: Record the affected file, command, exit code and risk.
• 60. document portability assumptions between Bash and POSIX sh: Record the affected file, command, exit code and risk.
• 61. name the shebang and target shell explicitly: Record the affected file, command, exit code and risk.
• 62. quote variable expansions unless word splitting is deliberate: Record the affected file, command, exit code and risk.
• 63. validate inputs before they influence filenames, options or commands: Record the affected file, command, exit code and risk.
• 64. evaluate and document exit codes explicitly: Record the affected file, command, exit code and risk.

Practice Appendix: Curriculum

This appendix is a working backlog for longer trainings, reviews and repetitions. Each task can be checked locally with Bash, test data and a Git repository.

A001. Interpreter

• Task: validate input and connect the observation explicitly to Interpreter.
• Evidence: Record the checked command, expected output, actual output and exit code.
• Operations question: What happens with empty input, missing files, missing tools and repeated execution?
• Security question: Can input become an option, path, glob, subshell, eval expression or secret leak?
• Recovery: Describe revert, cleanup, restore, secret rotation or manual correction.

A002. Quoting

• Task: explain exit code and connect the observation explicitly to Quoting.
• Evidence: Record the checked command, expected output, actual output and exit code.
• Operations question: What happens with empty input, missing files, missing tools and repeated execution?
• Security question: Can input become an option, path, glob, subshell, eval expression or secret leak?
• Recovery: Describe revert, cleanup, restore, secret rotation or manual correction.

A003. Exit Codes

• Task: check quoting and connect the observation explicitly to Exit Codes.
• Evidence: Record the checked command, expected output, actual output and exit code.
• Operations question: What happens with empty input, missing files, missing tools and repeated execution?
• Security question: Can input become an option, path, glob, subshell, eval expression or secret leak?
• Recovery: Describe revert, cleanup, restore, secret rotation or manual correction.

A004. Files

• Task: test error path and connect the observation explicitly to Files.
• Evidence: Record the checked command, expected output, actual output and exit code.
• Operations question: What happens with empty input, missing files, missing tools and repeated execution?
• Security question: Can input become an option, path, glob, subshell, eval expression or secret leak?
• Recovery: Describe revert, cleanup, restore, secret rotation or manual correction.

A005. Pipelines

• Task: review log output and connect the observation explicitly to Pipelines.
• Evidence: Record the checked command, expected output, actual output and exit code.
• Operations question: What happens with empty input, missing files, missing tools and repeated execution?
• Security question: Can input become an option, path, glob, subshell, eval expression or secret leak?
• Recovery: Describe revert, cleanup, restore, secret rotation or manual correction.

A006. Testing

• Task: trace cleanup and connect the observation explicitly to Testing.
• Evidence: Record the checked command, expected output, actual output and exit code.
• Operations question: What happens with empty input, missing files, missing tools and repeated execution?
• Security question: Can input become an option, path, glob, subshell, eval expression or secret leak?
• Recovery: Describe revert, cleanup, restore, secret rotation or manual correction.

A007. Security

• Task: scope portability and connect the observation explicitly to Security.
• Evidence: Record the checked command, expected output, actual output and exit code.
• Operations question: What happens with empty input, missing files, missing tools and repeated execution?
• Security question: Can input become an option, path, glob, subshell, eval expression or secret leak?
• Recovery: Describe revert, cleanup, restore, secret rotation or manual correction.

A008. Operations

• Task: mark security risk and connect the observation explicitly to Operations.
• Evidence: Record the checked command, expected output, actual output and exit code.
• Operations question: What happens with empty input, missing files, missing tools and repeated execution?
• Security question: Can input become an option, path, glob, subshell, eval expression or secret leak?
• Recovery: Describe revert, cleanup, restore, secret rotation or manual correction.

A009. Interpreter

• Task: document recovery path and connect the observation explicitly to Interpreter.
• Evidence: Record the checked command, expected output, actual output and exit code.
• Operations question: What happens with empty input, missing files, missing tools and repeated execution?
• Security question: Can input become an option, path, glob, subshell, eval expression or secret leak?
• Recovery: Describe revert, cleanup, restore, secret rotation or manual correction.

A010. Quoting

• Task: write review rule and connect the observation explicitly to Quoting.
• Evidence: Record the checked command, expected output, actual output and exit code.
• Operations question: What happens with empty input, missing files, missing tools and repeated execution?
• Security question: Can input become an option, path, glob, subshell, eval expression or secret leak?
• Recovery: Describe revert, cleanup, restore, secret rotation or manual correction.

A011. Exit Codes

• Task: validate input and connect the observation explicitly to Exit Codes.
• Evidence: Record the checked command, expected output, actual output and exit code.
• Operations question: What happens with empty input, missing files, missing tools and repeated execution?
• Security question: Can input become an option, path, glob, subshell, eval expression or secret leak?
• Recovery: Describe revert, cleanup, restore, secret rotation or manual correction.

A012. Files

• Task: explain exit code and connect the observation explicitly to Files.
• Evidence: Record the checked command, expected output, actual output and exit code.
• Operations question: What happens with empty input, missing files, missing tools and repeated execution?
• Security question: Can input become an option, path, glob, subshell, eval expression or secret leak?
• Recovery: Describe revert, cleanup, restore, secret rotation or manual correction.

A013. Pipelines

• Task: check quoting and connect the observation explicitly to Pipelines.
• Evidence: Record the checked command, expected output, actual output and exit code.
• Operations question: What happens with empty input, missing files, missing tools and repeated execution?
• Security question: Can input become an option, path, glob, subshell, eval expression or secret leak?
• Recovery: Describe revert, cleanup, restore, secret rotation or manual correction.

A014. Testing

• Task: test error path and connect the observation explicitly to Testing.
• Evidence: Record the checked command, expected output, actual output and exit code.
• Operations question: What happens with empty input, missing files, missing tools and repeated execution?
• Security question: Can input become an option, path, glob, subshell, eval expression or secret leak?
• Recovery: Describe revert, cleanup, restore, secret rotation or manual correction.

A015. Security

• Task: review log output and connect the observation explicitly to Security.
• Evidence: Record the checked command, expected output, actual output and exit code.
• Operations question: What happens with empty input, missing files, missing tools and repeated execution?
• Security question: Can input become an option, path, glob, subshell, eval expression or secret leak?
• Recovery: Describe revert, cleanup, restore, secret rotation or manual correction.

A016. Operations

• Task: trace cleanup and connect the observation explicitly to Operations.
• Evidence: Record the checked command, expected output, actual output and exit code.
• Operations question: What happens with empty input, missing files, missing tools and repeated execution?
• Security question: Can input become an option, path, glob, subshell, eval expression or secret leak?
• Recovery: Describe revert, cleanup, restore, secret rotation or manual correction.

A017. Interpreter

• Task: scope portability and connect the observation explicitly to Interpreter.
• Evidence: Record the checked command, expected output, actual output and exit code.
• Operations question: What happens with empty input, missing files, missing tools and repeated execution?
• Security question: Can input become an option, path, glob, subshell, eval expression or secret leak?
• Recovery: Describe revert, cleanup, restore, secret rotation or manual correction.

A018. Quoting

• Task: mark security risk and connect the observation explicitly to Quoting.
• Evidence: Record the checked command, expected output, actual output and exit code.
• Operations question: What happens with empty input, missing files, missing tools and repeated execution?
• Security question: Can input become an option, path, glob, subshell, eval expression or secret leak?
• Recovery: Describe revert, cleanup, restore, secret rotation or manual correction.

A019. Exit Codes

• Task: document recovery path and connect the observation explicitly to Exit Codes.
• Evidence: Record the checked command, expected output, actual output and exit code.
• Operations question: What happens with empty input, missing files, missing tools and repeated execution?
• Security question: Can input become an option, path, glob, subshell, eval expression or secret leak?
• Recovery: Describe revert, cleanup, restore, secret rotation or manual correction.

A020. Files

• Task: write review rule and connect the observation explicitly to Files.
• Evidence: Record the checked command, expected output, actual output and exit code.
• Operations question: What happens with empty input, missing files, missing tools and repeated execution?
• Security question: Can input become an option, path, glob, subshell, eval expression or secret leak?
• Recovery: Describe revert, cleanup, restore, secret rotation or manual correction.

A021. Pipelines

• Task: validate input and connect the observation explicitly to Pipelines.
• Evidence: Record the checked command, expected output, actual output and exit code.
• Operations question: What happens with empty input, missing files, missing tools and repeated execution?
• Security question: Can input become an option, path, glob, subshell, eval expression or secret leak?
• Recovery: Describe revert, cleanup, restore, secret rotation or manual correction.

A022. Testing

• Task: explain exit code and connect the observation explicitly to Testing.
• Evidence: Record the checked command, expected output, actual output and exit code.
• Operations question: What happens with empty input, missing files, missing tools and repeated execution?
• Security question: Can input become an option, path, glob, subshell, eval expression or secret leak?
• Recovery: Describe revert, cleanup, restore, secret rotation or manual correction.

A023. Security

• Task: check quoting and connect the observation explicitly to Security.
• Evidence: Record the checked command, expected output, actual output and exit code.
• Operations question: What happens with empty input, missing files, missing tools and repeated execution?
• Security question: Can input become an option, path, glob, subshell, eval expression or secret leak?
• Recovery: Describe revert, cleanup, restore, secret rotation or manual correction.

A024. Operations

• Task: test error path and connect the observation explicitly to Operations.
• Evidence: Record the checked command, expected output, actual output and exit code.
• Operations question: What happens with empty input, missing files, missing tools and repeated execution?
• Security question: Can input become an option, path, glob, subshell, eval expression or secret leak?
• Recovery: Describe revert, cleanup, restore, secret rotation or manual correction.

A025. Interpreter

• Task: review log output and connect the observation explicitly to Interpreter.
• Evidence: Record the checked command, expected output, actual output and exit code.
• Operations question: What happens with empty input, missing files, missing tools and repeated execution?
• Security question: Can input become an option, path, glob, subshell, eval expression or secret leak?
• Recovery: Describe revert, cleanup, restore, secret rotation or manual correction.

A026. Quoting

• Task: trace cleanup and connect the observation explicitly to Quoting.
• Evidence: Record the checked command, expected output, actual output and exit code.
• Operations question: What happens with empty input, missing files, missing tools and repeated execution?
• Security question: Can input become an option, path, glob, subshell, eval expression or secret leak?
• Recovery: Describe revert, cleanup, restore, secret rotation or manual correction.

A027. Exit Codes

• Task: scope portability and connect the observation explicitly to Exit Codes.
• Evidence: Record the checked command, expected output, actual output and exit code.
• Operations question: What happens with empty input, missing files, missing tools and repeated execution?
• Security question: Can input become an option, path, glob, subshell, eval expression or secret leak?
• Recovery: Describe revert, cleanup, restore, secret rotation or manual correction.

A028. Files

• Task: mark security risk and connect the observation explicitly to Files.
• Evidence: Record the checked command, expected output, actual output and exit code.
• Operations question: What happens with empty input, missing files, missing tools and repeated execution?
• Security question: Can input become an option, path, glob, subshell, eval expression or secret leak?
• Recovery: Describe revert, cleanup, restore, secret rotation or manual correction.

A029. Pipelines

• Task: document recovery path and connect the observation explicitly to Pipelines.
• Evidence: Record the checked command, expected output, actual output and exit code.
• Operations question: What happens with empty input, missing files, missing tools and repeated execution?
• Security question: Can input become an option, path, glob, subshell, eval expression or secret leak?
• Recovery: Describe revert, cleanup, restore, secret rotation or manual correction.

A030. Testing

• Task: write review rule and connect the observation explicitly to Testing.
• Evidence: Record the checked command, expected output, actual output and exit code.
• Operations question: What happens with empty input, missing files, missing tools and repeated execution?
• Security question: Can input become an option, path, glob, subshell, eval expression or secret leak?
• Recovery: Describe revert, cleanup, restore, secret rotation or manual correction.

A031. Security

• Task: validate input and connect the observation explicitly to Security.
• Evidence: Record the checked command, expected output, actual output and exit code.
• Operations question: What happens with empty input, missing files, missing tools and repeated execution?
• Security question: Can input become an option, path, glob, subshell, eval expression or secret leak?
• Recovery: Describe revert, cleanup, restore, secret rotation or manual correction.

A032. Operations

• Task: explain exit code and connect the observation explicitly to Operations.
• Evidence: Record the checked command, expected output, actual output and exit code.
• Operations question: What happens with empty input, missing files, missing tools and repeated execution?
• Security question: Can input become an option, path, glob, subshell, eval expression or secret leak?
• Recovery: Describe revert, cleanup, restore, secret rotation or manual correction.

A033. Interpreter

• Task: check quoting and connect the observation explicitly to Interpreter.
• Evidence: Record the checked command, expected output, actual output and exit code.
• Operations question: What happens with empty input, missing files, missing tools and repeated execution?
• Security question: Can input become an option, path, glob, subshell, eval expression or secret leak?
• Recovery: Describe revert, cleanup, restore, secret rotation or manual correction.

A034. Quoting

• Task: test error path and connect the observation explicitly to Quoting.
• Evidence: Record the checked command, expected output, actual output and exit code.
• Operations question: What happens with empty input, missing files, missing tools and repeated execution?
• Security question: Can input become an option, path, glob, subshell, eval expression or secret leak?
• Recovery: Describe revert, cleanup, restore, secret rotation or manual correction.

A035. Exit Codes

• Task: review log output and connect the observation explicitly to Exit Codes.
• Evidence: Record the checked command, expected output, actual output and exit code.
• Operations question: What happens with empty input, missing files, missing tools and repeated execution?
• Security question: Can input become an option, path, glob, subshell, eval expression or secret leak?
• Recovery: Describe revert, cleanup, restore, secret rotation or manual correction.

A036. Files

• Task: trace cleanup and connect the observation explicitly to Files.
• Evidence: Record the checked command, expected output, actual output and exit code.
• Operations question: What happens with empty input, missing files, missing tools and repeated execution?
• Security question: Can input become an option, path, glob, subshell, eval expression or secret leak?
• Recovery: Describe revert, cleanup, restore, secret rotation or manual correction.

A037. Pipelines

• Task: scope portability and connect the observation explicitly to Pipelines.
• Evidence: Record the checked command, expected output, actual output and exit code.
• Operations question: What happens with empty input, missing files, missing tools and repeated execution?
• Security question: Can input become an option, path, glob, subshell, eval expression or secret leak?
• Recovery: Describe revert, cleanup, restore, secret rotation or manual correction.

A038. Testing

• Task: mark security risk and connect the observation explicitly to Testing.
• Evidence: Record the checked command, expected output, actual output and exit code.
• Operations question: What happens with empty input, missing files, missing tools and repeated execution?
• Security question: Can input become an option, path, glob, subshell, eval expression or secret leak?
• Recovery: Describe revert, cleanup, restore, secret rotation or manual correction.

A039. Security

• Task: document recovery path and connect the observation explicitly to Security.
• Evidence: Record the checked command, expected output, actual output and exit code.
• Operations question: What happens with empty input, missing files, missing tools and repeated execution?
• Security question: Can input become an option, path, glob, subshell, eval expression or secret leak?
• Recovery: Describe revert, cleanup, restore, secret rotation or manual correction.

A040. Operations

• Task: write review rule and connect the observation explicitly to Operations.
• Evidence: Record the checked command, expected output, actual output and exit code.
• Operations question: What happens with empty input, missing files, missing tools and repeated execution?
• Security question: Can input become an option, path, glob, subshell, eval expression or secret leak?
• Recovery: Describe revert, cleanup, restore, secret rotation or manual correction.

A041. Interpreter

• Task: validate input and connect the observation explicitly to Interpreter.
• Evidence: Record the checked command, expected output, actual output and exit code.
• Operations question: What happens with empty input, missing files, missing tools and repeated execution?
• Security question: Can input become an option, path, glob, subshell, eval expression or secret leak?
• Recovery: Describe revert, cleanup, restore, secret rotation or manual correction.

A042. Quoting

• Task: explain exit code and connect the observation explicitly to Quoting.
• Evidence: Record the checked command, expected output, actual output and exit code.
• Operations question: What happens with empty input, missing files, missing tools and repeated execution?
• Security question: Can input become an option, path, glob, subshell, eval expression or secret leak?
• Recovery: Describe revert, cleanup, restore, secret rotation or manual correction.

A043. Exit Codes

• Task: check quoting and connect the observation explicitly to Exit Codes.
• Evidence: Record the checked command, expected output, actual output and exit code.
• Operations question: What happens with empty input, missing files, missing tools and repeated execution?
• Security question: Can input become an option, path, glob, subshell, eval expression or secret leak?
• Recovery: Describe revert, cleanup, restore, secret rotation or manual correction.

A044. Files

• Task: test error path and connect the observation explicitly to Files.
• Evidence: Record the checked command, expected output, actual output and exit code.
• Operations question: What happens with empty input, missing files, missing tools and repeated execution?
• Security question: Can input become an option, path, glob, subshell, eval expression or secret leak?
• Recovery: Describe revert, cleanup, restore, secret rotation or manual correction.

A045. Pipelines

• Task: review log output and connect the observation explicitly to Pipelines.
• Evidence: Record the checked command, expected output, actual output and exit code.
• Operations question: What happens with empty input, missing files, missing tools and repeated execution?
• Security question: Can input become an option, path, glob, subshell, eval expression or secret leak?
• Recovery: Describe revert, cleanup, restore, secret rotation or manual correction.

A046. Testing

• Task: trace cleanup and connect the observation explicitly to Testing.
• Evidence: Record the checked command, expected output, actual output and exit code.
• Operations question: What happens with empty input, missing files, missing tools and repeated execution?
• Security question: Can input become an option, path, glob, subshell, eval expression or secret leak?
• Recovery: Describe revert, cleanup, restore, secret rotation or manual correction.

A047. Security

• Task: scope portability and connect the observation explicitly to Security.
• Evidence: Record the checked command, expected output, actual output and exit code.
• Operations question: What happens with empty input, missing files, missing tools and repeated execution?
• Security question: Can input become an option, path, glob, subshell, eval expression or secret leak?
• Recovery: Describe revert, cleanup, restore, secret rotation or manual correction.

A048. Operations

• Task: mark security risk and connect the observation explicitly to Operations.
• Evidence: Record the checked command, expected output, actual output and exit code.
• Operations question: What happens with empty input, missing files, missing tools and repeated execution?
• Security question: Can input become an option, path, glob, subshell, eval expression or secret leak?
• Recovery: Describe revert, cleanup, restore, secret rotation or manual correction.

A049. Interpreter

• Task: document recovery path and connect the observation explicitly to Interpreter.
• Evidence: Record the checked command, expected output, actual output and exit code.
• Operations question: What happens with empty input, missing files, missing tools and repeated execution?
• Security question: Can input become an option, path, glob, subshell, eval expression or secret leak?
• Recovery: Describe revert, cleanup, restore, secret rotation or manual correction.

A050. Quoting

• Task: write review rule and connect the observation explicitly to Quoting.
• Evidence: Record the checked command, expected output, actual output and exit code.
• Operations question: What happens with empty input, missing files, missing tools and repeated execution?
• Security question: Can input become an option, path, glob, subshell, eval expression or secret leak?
• Recovery: Describe revert, cleanup, restore, secret rotation or manual correction.

A051. Exit Codes

• Task: validate input and connect the observation explicitly to Exit Codes.
• Evidence: Record the checked command, expected output, actual output and exit code.
• Operations question: What happens with empty input, missing files, missing tools and repeated execution?
• Security question: Can input become an option, path, glob, subshell, eval expression or secret leak?
• Recovery: Describe revert, cleanup, restore, secret rotation or manual correction.

A052. Files

• Task: explain exit code and connect the observation explicitly to Files.
• Evidence: Record the checked command, expected output, actual output and exit code.
• Operations question: What happens with empty input, missing files, missing tools and repeated execution?
• Security question: Can input become an option, path, glob, subshell, eval expression or secret leak?
• Recovery: Describe revert, cleanup, restore, secret rotation or manual correction.

A053. Pipelines

• Task: check quoting and connect the observation explicitly to Pipelines.
• Evidence: Record the checked command, expected output, actual output and exit code.
• Operations question: What happens with empty input, missing files, missing tools and repeated execution?
• Security question: Can input become an option, path, glob, subshell, eval expression or secret leak?
• Recovery: Describe revert, cleanup, restore, secret rotation or manual correction.

A054. Testing

• Task: test error path and connect the observation explicitly to Testing.
• Evidence: Record the checked command, expected output, actual output and exit code.
• Operations question: What happens with empty input, missing files, missing tools and repeated execution?
• Security question: Can input become an option, path, glob, subshell, eval expression or secret leak?
• Recovery: Describe revert, cleanup, restore, secret rotation or manual correction.

A055. Security

• Task: review log output and connect the observation explicitly to Security.
• Evidence: Record the checked command, expected output, actual output and exit code.
• Operations question: What happens with empty input, missing files, missing tools and repeated execution?
• Security question: Can input become an option, path, glob, subshell, eval expression or secret leak?
• Recovery: Describe revert, cleanup, restore, secret rotation or manual correction.

A056. Operations

• Task: trace cleanup and connect the observation explicitly to Operations.
• Evidence: Record the checked command, expected output, actual output and exit code.
• Operations question: What happens with empty input, missing files, missing tools and repeated execution?
• Security question: Can input become an option, path, glob, subshell, eval expression or secret leak?
• Recovery: Describe revert, cleanup, restore, secret rotation or manual correction.

A057. Interpreter

• Task: scope portability and connect the observation explicitly to Interpreter.
• Evidence: Record the checked command, expected output, actual output and exit code.
• Operations question: What happens with empty input, missing files, missing tools and repeated execution?
• Security question: Can input become an option, path, glob, subshell, eval expression or secret leak?
• Recovery: Describe revert, cleanup, restore, secret rotation or manual correction.

A058. Quoting

• Task: mark security risk and connect the observation explicitly to Quoting.
• Evidence: Record the checked command, expected output, actual output and exit code.
• Operations question: What happens with empty input, missing files, missing tools and repeated execution?
• Security question: Can input become an option, path, glob, subshell, eval expression or secret leak?
• Recovery: Describe revert, cleanup, restore, secret rotation or manual correction.

A059. Exit Codes

• Task: document recovery path and connect the observation explicitly to Exit Codes.
• Evidence: Record the checked command, expected output, actual output and exit code.
• Operations question: What happens with empty input, missing files, missing tools and repeated execution?
• Security question: Can input become an option, path, glob, subshell, eval expression or secret leak?
• Recovery: Describe revert, cleanup, restore, secret rotation or manual correction.

A060. Files

• Task: write review rule and connect the observation explicitly to Files.
• Evidence: Record the checked command, expected output, actual output and exit code.
• Operations question: What happens with empty input, missing files, missing tools and repeated execution?
• Security question: Can input become an option, path, glob, subshell, eval expression or secret leak?
• Recovery: Describe revert, cleanup, restore, secret rotation or manual correction.

A061. Pipelines

• Task: validate input and connect the observation explicitly to Pipelines.
• Evidence: Record the checked command, expected output, actual output and exit code.
• Operations question: What happens with empty input, missing files, missing tools and repeated execution?
• Security question: Can input become an option, path, glob, subshell, eval expression or secret leak?
• Recovery: Describe revert, cleanup, restore, secret rotation or manual correction.

A062. Testing

• Task: explain exit code and connect the observation explicitly to Testing.
• Evidence: Record the checked command, expected output, actual output and exit code.
• Operations question: What happens with empty input, missing files, missing tools and repeated execution?
• Security question: Can input become an option, path, glob, subshell, eval expression or secret leak?
• Recovery: Describe revert, cleanup, restore, secret rotation or manual correction.

A063. Security

• Task: check quoting and connect the observation explicitly to Security.
• Evidence: Record the checked command, expected output, actual output and exit code.
• Operations question: What happens with empty input, missing files, missing tools and repeated execution?
• Security question: Can input become an option, path, glob, subshell, eval expression or secret leak?
• Recovery: Describe revert, cleanup, restore, secret rotation or manual correction.

A064. Operations

• Task: test error path and connect the observation explicitly to Operations.
• Evidence: Record the checked command, expected output, actual output and exit code.
• Operations question: What happens with empty input, missing files, missing tools and repeated execution?
• Security question: Can input become an option, path, glob, subshell, eval expression or secret leak?
• Recovery: Describe revert, cleanup, restore, secret rotation or manual correction.

A065. Interpreter

• Task: review log output and connect the observation explicitly to Interpreter.
• Evidence: Record the checked command, expected output, actual output and exit code.
• Operations question: What happens with empty input, missing files, missing tools and repeated execution?
• Security question: Can input become an option, path, glob, subshell, eval expression or secret leak?
• Recovery: Describe revert, cleanup, restore, secret rotation or manual correction.

A066. Quoting

• Task: trace cleanup and connect the observation explicitly to Quoting.
• Evidence: Record the checked command, expected output, actual output and exit code.
• Operations question: What happens with empty input, missing files, missing tools and repeated execution?
• Security question: Can input become an option, path, glob, subshell, eval expression or secret leak?
• Recovery: Describe revert, cleanup, restore, secret rotation or manual correction.

A067. Exit Codes

• Task: scope portability and connect the observation explicitly to Exit Codes.
• Evidence: Record the checked command, expected output, actual output and exit code.
• Operations question: What happens with empty input, missing files, missing tools and repeated execution?
• Security question: Can input become an option, path, glob, subshell, eval expression or secret leak?
• Recovery: Describe revert, cleanup, restore, secret rotation or manual correction.

A068. Files

• Task: mark security risk and connect the observation explicitly to Files.
• Evidence: Record the checked command, expected output, actual output and exit code.
• Operations question: What happens with empty input, missing files, missing tools and repeated execution?
• Security question: Can input become an option, path, glob, subshell, eval expression or secret leak?
• Recovery: Describe revert, cleanup, restore, secret rotation or manual correction.

A069. Pipelines

• Task: document recovery path and connect the observation explicitly to Pipelines.
• Evidence: Record the checked command, expected output, actual output and exit code.
• Operations question: What happens with empty input, missing files, missing tools and repeated execution?
• Security question: Can input become an option, path, glob, subshell, eval expression or secret leak?
• Recovery: Describe revert, cleanup, restore, secret rotation or manual correction.

A070. Testing

• Task: write review rule and connect the observation explicitly to Testing.
• Evidence: Record the checked command, expected output, actual output and exit code.
• Operations question: What happens with empty input, missing files, missing tools and repeated execution?
• Security question: Can input become an option, path, glob, subshell, eval expression or secret leak?
• Recovery: Describe revert, cleanup, restore, secret rotation or manual correction.

A071. Security

• Task: validate input and connect the observation explicitly to Security.
• Evidence: Record the checked command, expected output, actual output and exit code.
• Operations question: What happens with empty input, missing files, missing tools and repeated execution?
• Security question: Can input become an option, path, glob, subshell, eval expression or secret leak?
• Recovery: Describe revert, cleanup, restore, secret rotation or manual correction.

A072. Operations

• Task: explain exit code and connect the observation explicitly to Operations.
• Evidence: Record the checked command, expected output, actual output and exit code.
• Operations question: What happens with empty input, missing files, missing tools and repeated execution?
• Security question: Can input become an option, path, glob, subshell, eval expression or secret leak?
• Recovery: Describe revert, cleanup, restore, secret rotation or manual correction.

A073. Interpreter

• Task: check quoting and connect the observation explicitly to Interpreter.
• Evidence: Record the checked command, expected output, actual output and exit code.
• Operations question: What happens with empty input, missing files, missing tools and repeated execution?
• Security question: Can input become an option, path, glob, subshell, eval expression or secret leak?
• Recovery: Describe revert, cleanup, restore, secret rotation or manual correction.

A074. Quoting

• Task: test error path and connect the observation explicitly to Quoting.
• Evidence: Record the checked command, expected output, actual output and exit code.
• Operations question: What happens with empty input, missing files, missing tools and repeated execution?
• Security question: Can input become an option, path, glob, subshell, eval expression or secret leak?
• Recovery: Describe revert, cleanup, restore, secret rotation or manual correction.

A075. Exit Codes

• Task: review log output and connect the observation explicitly to Exit Codes.
• Evidence: Record the checked command, expected output, actual output and exit code.
• Operations question: What happens with empty input, missing files, missing tools and repeated execution?
• Security question: Can input become an option, path, glob, subshell, eval expression or secret leak?
• Recovery: Describe revert, cleanup, restore, secret rotation or manual correction.

A076. Files

• Task: trace cleanup and connect the observation explicitly to Files.
• Evidence: Record the checked command, expected output, actual output and exit code.
• Operations question: What happens with empty input, missing files, missing tools and repeated execution?
• Security question: Can input become an option, path, glob, subshell, eval expression or secret leak?
• Recovery: Describe revert, cleanup, restore, secret rotation or manual correction.

A077. Pipelines

• Task: scope portability and connect the observation explicitly to Pipelines.
• Evidence: Record the checked command, expected output, actual output and exit code.
• Operations question: What happens with empty input, missing files, missing tools and repeated execution?
• Security question: Can input become an option, path, glob, subshell, eval expression or secret leak?
• Recovery: Describe revert, cleanup, restore, secret rotation or manual correction.

A078. Testing

• Task: mark security risk and connect the observation explicitly to Testing.
• Evidence: Record the checked command, expected output, actual output and exit code.
• Operations question: What happens with empty input, missing files, missing tools and repeated execution?
• Security question: Can input become an option, path, glob, subshell, eval expression or secret leak?
• Recovery: Describe revert, cleanup, restore, secret rotation or manual correction.

A079. Security

• Task: document recovery path and connect the observation explicitly to Security.
• Evidence: Record the checked command, expected output, actual output and exit code.
• Operations question: What happens with empty input, missing files, missing tools and repeated execution?
• Security question: Can input become an option, path, glob, subshell, eval expression or secret leak?
• Recovery: Describe revert, cleanup, restore, secret rotation or manual correction.

A080. Operations

• Task: write review rule and connect the observation explicitly to Operations.
• Evidence: Record the checked command, expected output, actual output and exit code.
• Operations question: What happens with empty input, missing files, missing tools and repeated execution?
• Security question: Can input become an option, path, glob, subshell, eval expression or secret leak?
• Recovery: Describe revert, cleanup, restore, secret rotation or manual correction.

A081. Interpreter

• Task: validate input and connect the observation explicitly to Interpreter.
• Evidence: Record the checked command, expected output, actual output and exit code.
• Operations question: What happens with empty input, missing files, missing tools and repeated execution?
• Security question: Can input become an option, path, glob, subshell, eval expression or secret leak?
• Recovery: Describe revert, cleanup, restore, secret rotation or manual correction.

A082. Quoting

• Task: explain exit code and connect the observation explicitly to Quoting.
• Evidence: Record the checked command, expected output, actual output and exit code.
• Operations question: What happens with empty input, missing files, missing tools and repeated execution?
• Security question: Can input become an option, path, glob, subshell, eval expression or secret leak?
• Recovery: Describe revert, cleanup, restore, secret rotation or manual correction.

A083. Exit Codes

• Task: check quoting and connect the observation explicitly to Exit Codes.
• Evidence: Record the checked command, expected output, actual output and exit code.
• Operations question: What happens with empty input, missing files, missing tools and repeated execution?
• Security question: Can input become an option, path, glob, subshell, eval expression or secret leak?
• Recovery: Describe revert, cleanup, restore, secret rotation or manual correction.

A084. Files

• Task: test error path and connect the observation explicitly to Files.
• Evidence: Record the checked command, expected output, actual output and exit code.
• Operations question: What happens with empty input, missing files, missing tools and repeated execution?
• Security question: Can input become an option, path, glob, subshell, eval expression or secret leak?
• Recovery: Describe revert, cleanup, restore, secret rotation or manual correction.

A085. Pipelines

• Task: review log output and connect the observation explicitly to Pipelines.
• Evidence: Record the checked command, expected output, actual output and exit code.
• Operations question: What happens with empty input, missing files, missing tools and repeated execution?
• Security question: Can input become an option, path, glob, subshell, eval expression or secret leak?
• Recovery: Describe revert, cleanup, restore, secret rotation or manual correction.

A086. Testing

• Task: trace cleanup and connect the observation explicitly to Testing.
• Evidence: Record the checked command, expected output, actual output and exit code.
• Operations question: What happens with empty input, missing files, missing tools and repeated execution?
• Security question: Can input become an option, path, glob, subshell, eval expression or secret leak?
• Recovery: Describe revert, cleanup, restore, secret rotation or manual correction.

A087. Security

• Task: scope portability and connect the observation explicitly to Security.
• Evidence: Record the checked command, expected output, actual output and exit code.
• Operations question: What happens with empty input, missing files, missing tools and repeated execution?
• Security question: Can input become an option, path, glob, subshell, eval expression or secret leak?
• Recovery: Describe revert, cleanup, restore, secret rotation or manual correction.

A088. Operations

• Task: mark security risk and connect the observation explicitly to Operations.
• Evidence: Record the checked command, expected output, actual output and exit code.
• Operations question: What happens with empty input, missing files, missing tools and repeated execution?
• Security question: Can input become an option, path, glob, subshell, eval expression or secret leak?
• Recovery: Describe revert, cleanup, restore, secret rotation or manual correction.

A089. Interpreter

• Task: document recovery path and connect the observation explicitly to Interpreter.
• Evidence: Record the checked command, expected output, actual output and exit code.
• Operations question: What happens with empty input, missing files, missing tools and repeated execution?
• Security question: Can input become an option, path, glob, subshell, eval expression or secret leak?
• Recovery: Describe revert, cleanup, restore, secret rotation or manual correction.

A090. Quoting

• Task: write review rule and connect the observation explicitly to Quoting.
• Evidence: Record the checked command, expected output, actual output and exit code.
• Operations question: What happens with empty input, missing files, missing tools and repeated execution?
• Security question: Can input become an option, path, glob, subshell, eval expression or secret leak?
• Recovery: Describe revert, cleanup, restore, secret rotation or manual correction.

A091. Exit Codes

• Task: validate input and connect the observation explicitly to Exit Codes.
• Evidence: Record the checked command, expected output, actual output and exit code.
• Operations question: What happens with empty input, missing files, missing tools and repeated execution?
• Security question: Can input become an option, path, glob, subshell, eval expression or secret leak?
• Recovery: Describe revert, cleanup, restore, secret rotation or manual correction.

A092. Files

• Task: explain exit code and connect the observation explicitly to Files.
• Evidence: Record the checked command, expected output, actual output and exit code.
• Operations question: What happens with empty input, missing files, missing tools and repeated execution?
• Security question: Can input become an option, path, glob, subshell, eval expression or secret leak?
• Recovery: Describe revert, cleanup, restore, secret rotation or manual correction.

A093. Pipelines

• Task: check quoting and connect the observation explicitly to Pipelines.
• Evidence: Record the checked command, expected output, actual output and exit code.
• Operations question: What happens with empty input, missing files, missing tools and repeated execution?
• Security question: Can input become an option, path, glob, subshell, eval expression or secret leak?
• Recovery: Describe revert, cleanup, restore, secret rotation or manual correction.

A094. Testing

• Task: test error path and connect the observation explicitly to Testing.
• Evidence: Record the checked command, expected output, actual output and exit code.
• Operations question: What happens with empty input, missing files, missing tools and repeated execution?
• Security question: Can input become an option, path, glob, subshell, eval expression or secret leak?
• Recovery: Describe revert, cleanup, restore, secret rotation or manual correction.

A095. Security

• Task: review log output and connect the observation explicitly to Security.
• Evidence: Record the checked command, expected output, actual output and exit code.
• Operations question: What happens with empty input, missing files, missing tools and repeated execution?
• Security question: Can input become an option, path, glob, subshell, eval expression or secret leak?
• Recovery: Describe revert, cleanup, restore, secret rotation or manual correction.

A096. Operations

• Task: trace cleanup and connect the observation explicitly to Operations.
• Evidence: Record the checked command, expected output, actual output and exit code.
• Operations question: What happens with empty input, missing files, missing tools and repeated execution?
• Security question: Can input become an option, path, glob, subshell, eval expression or secret leak?
• Recovery: Describe revert, cleanup, restore, secret rotation or manual correction.

A097. Interpreter

• Task: scope portability and connect the observation explicitly to Interpreter.
• Evidence: Record the checked command, expected output, actual output and exit code.
• Operations question: What happens with empty input, missing files, missing tools and repeated execution?
• Security question: Can input become an option, path, glob, subshell, eval expression or secret leak?
• Recovery: Describe revert, cleanup, restore, secret rotation or manual correction.

A098. Quoting

• Task: mark security risk and connect the observation explicitly to Quoting.
• Evidence: Record the checked command, expected output, actual output and exit code.
• Operations question: What happens with empty input, missing files, missing tools and repeated execution?
• Security question: Can input become an option, path, glob, subshell, eval expression or secret leak?
• Recovery: Describe revert, cleanup, restore, secret rotation or manual correction.

A099. Exit Codes

• Task: document recovery path and connect the observation explicitly to Exit Codes.
• Evidence: Record the checked command, expected output, actual output and exit code.
• Operations question: What happens with empty input, missing files, missing tools and repeated execution?
• Security question: Can input become an option, path, glob, subshell, eval expression or secret leak?
• Recovery: Describe revert, cleanup, restore, secret rotation or manual correction.

A100. Files

• Task: write review rule and connect the observation explicitly to Files.
• Evidence: Record the checked command, expected output, actual output and exit code.
• Operations question: What happens with empty input, missing files, missing tools and repeated execution?
• Security question: Can input become an option, path, glob, subshell, eval expression or secret leak?
• Recovery: Describe revert, cleanup, restore, secret rotation or manual correction.

A101. Pipelines

• Task: validate input and connect the observation explicitly to Pipelines.
• Evidence: Record the checked command, expected output, actual output and exit code.
• Operations question: What happens with empty input, missing files, missing tools and repeated execution?
• Security question: Can input become an option, path, glob, subshell, eval expression or secret leak?
• Recovery: Describe revert, cleanup, restore, secret rotation or manual correction.

A102. Testing

• Task: explain exit code and connect the observation explicitly to Testing.
• Evidence: Record the checked command, expected output, actual output and exit code.
• Operations question: What happens with empty input, missing files, missing tools and repeated execution?
• Security question: Can input become an option, path, glob, subshell, eval expression or secret leak?
• Recovery: Describe revert, cleanup, restore, secret rotation or manual correction.

A103. Security

• Task: check quoting and connect the observation explicitly to Security.
• Evidence: Record the checked command, expected output, actual output and exit code.
• Operations question: What happens with empty input, missing files, missing tools and repeated execution?
• Security question: Can input become an option, path, glob, subshell, eval expression or secret leak?
• Recovery: Describe revert, cleanup, restore, secret rotation or manual correction.

A104. Operations

• Task: test error path and connect the observation explicitly to Operations.
• Evidence: Record the checked command, expected output, actual output and exit code.
• Operations question: What happens with empty input, missing files, missing tools and repeated execution?
• Security question: Can input become an option, path, glob, subshell, eval expression or secret leak?
• Recovery: Describe revert, cleanup, restore, secret rotation or manual correction.

A105. Interpreter

• Task: review log output and connect the observation explicitly to Interpreter.
• Evidence: Record the checked command, expected output, actual output and exit code.
• Operations question: What happens with empty input, missing files, missing tools and repeated execution?
• Security question: Can input become an option, path, glob, subshell, eval expression or secret leak?
• Recovery: Describe revert, cleanup, restore, secret rotation or manual correction.

A106. Quoting

• Task: trace cleanup and connect the observation explicitly to Quoting.
• Evidence: Record the checked command, expected output, actual output and exit code.
• Operations question: What happens with empty input, missing files, missing tools and repeated execution?
• Security question: Can input become an option, path, glob, subshell, eval expression or secret leak?
• Recovery: Describe revert, cleanup, restore, secret rotation or manual correction.

A107. Exit Codes

• Task: scope portability and connect the observation explicitly to Exit Codes.
• Evidence: Record the checked command, expected output, actual output and exit code.
• Operations question: What happens with empty input, missing files, missing tools and repeated execution?
• Security question: Can input become an option, path, glob, subshell, eval expression or secret leak?
• Recovery: Describe revert, cleanup, restore, secret rotation or manual correction.

A108. Files

• Task: mark security risk and connect the observation explicitly to Files.
• Evidence: Record the checked command, expected output, actual output and exit code.
• Operations question: What happens with empty input, missing files, missing tools and repeated execution?
• Security question: Can input become an option, path, glob, subshell, eval expression or secret leak?
• Recovery: Describe revert, cleanup, restore, secret rotation or manual correction.

A109. Pipelines

• Task: document recovery path and connect the observation explicitly to Pipelines.
• Evidence: Record the checked command, expected output, actual output and exit code.
• Operations question: What happens with empty input, missing files, missing tools and repeated execution?
• Security question: Can input become an option, path, glob, subshell, eval expression or secret leak?
• Recovery: Describe revert, cleanup, restore, secret rotation or manual correction.

A110. Testing

• Task: write review rule and connect the observation explicitly to Testing.
• Evidence: Record the checked command, expected output, actual output and exit code.
• Operations question: What happens with empty input, missing files, missing tools and repeated execution?
• Security question: Can input become an option, path, glob, subshell, eval expression or secret leak?
• Recovery: Describe revert, cleanup, restore, secret rotation or manual correction.

A111. Security

• Task: validate input and connect the observation explicitly to Security.
• Evidence: Record the checked command, expected output, actual output and exit code.
• Operations question: What happens with empty input, missing files, missing tools and repeated execution?
• Security question: Can input become an option, path, glob, subshell, eval expression or secret leak?
• Recovery: Describe revert, cleanup, restore, secret rotation or manual correction.

A112. Operations

• Task: explain exit code and connect the observation explicitly to Operations.
• Evidence: Record the checked command, expected output, actual output and exit code.
• Operations question: What happens with empty input, missing files, missing tools and repeated execution?
• Security question: Can input become an option, path, glob, subshell, eval expression or secret leak?
• Recovery: Describe revert, cleanup, restore, secret rotation or manual correction.