A glob pattern is a wildcard string used to match filenames, paths, or other text values. It typically uses symbols such as * for any sequence of characters and ? for a single character, and is common in shells, file filters, build tools, and access rules.
How Glob Patterns Work
Glob patterns are compact matching strings used to select filenames, paths, or text by rule rather than by exact value. The usual wildcard symbols are * for any sequence of characters and ? for a single character, with many tools also supporting bracket expressions for character sets or ranges.
The basic idea is simple, but the exact syntax varies by shell, runtime library, build system, and product. That matters because a pattern that works one place may behave differently elsewhere, especially around path separators, hidden files, escaping, and whether matching is case-sensitive.
In practice, globbing is most visible in shells and file tools, but the same pattern style appears in backup jobs, deployment scripts, ignore files, search filters, and access rules. The appeal is readability: operators can describe a broad set of names without writing a full regular expression.
Where Glob Patterns Are Used
Glob patterns are a convenience layer over many common file and text operations. They are used to match groups of files during copying, packaging, deletion, scanning, or filtering, and they often determine what a tool includes or excludes by default.
They also show up in configuration files and policy-like settings, where a short pattern can govern which resources are in scope. That makes them powerful, but it also means a small syntax mistake can affect a much larger set of files or records than intended.
Because glob syntax is intentionally lightweight, it is usually easier to read than a complex regular expression. The trade-off is expressive limits, which is why developers sometimes combine glob patterns with other matching logic when they need finer control.
Common Matching Rules and Variants
Most glob implementations share a common core, but not a single universal standard. Some treat * as matching across path separators, while others stop at directory boundaries; some support recursive matching with special double-star behaviour, while others do not.
Hidden files are another frequent source of confusion. In many environments, a leading dot is not matched by ordinary wildcards unless the pattern explicitly accounts for it, which can cause files to be skipped unexpectedly during automation or cleanup.
Escaping also matters. If a literal *, ?, or bracket character is needed in the target name, it usually has to be escaped or quoted so the tool interprets it as data rather than as a wildcard.
Why Glob Patterns Matter for Security and Reliability
Glob patterns are not just a convenience feature, they can become a control surface. A broad pattern can unintentionally include secrets, logs, backups, or configuration files, while an overly narrow pattern can leave important files unchecked or unprotected.
They also influence trust boundaries in tooling. If a pattern is used to decide what gets deployed, ignored, scanned, or granted access, the security outcome depends on how precisely that pattern is interpreted by the underlying system.
EU Digital Operational Resilience Act (DORA) and EU NIS2 Directive both illustrate why scope control matters, because operational tooling and access logic need to be predictable when they govern regulated environments.
Standards & Framework Alignment
This section maps relevant standards and security frameworks to the operational risks and controls described in this guidance.
NIST SP 800-53 Rev 5, NIST CSF 2.0 and CIS Controls v8 set the technical controls, while ISO/IEC 27001:2022 defines the regulatory obligations.
| Framework | Control / Reference | Relevance |
|---|---|---|
| NIST SP 800-53 Rev 5 | AC-3 — Access Enforcement | Glob patterns can define which resources are included in access rules or filters. |
| CM-6 — Configuration Settings | Glob patterns are often embedded in configuration that controls file and path handling. | |
| Recommendation — Validate pattern-based rule scopes to enforce the intended access decision. Review pattern-driven configuration settings before deployment and change them carefully. | ||
| NIST CSF 2.0 | PR.AA-05 — Identity Management, Authentication and Access Control | Pattern-based access and scope decisions can shape who or what is allowed to act. |
| Recommendation — Apply least-privilege scope controls when patterns influence access decisions. | ||
| ISO/IEC 27001:2022 | A.8.9 — Configuration management | Glob patterns are configuration inputs whose correctness affects security and reliability. |
| Recommendation — Control and review pattern-based configuration changes before release. | ||
| CIS Controls v8 | CIS-4 — Secure Configuration of Enterprise Assets and Software | Glob patterns affect software and system configuration, including filters and exclusions. |
| Recommendation — Harden and validate pattern-based configurations that affect system behaviour. | ||
Practitioner Guidance
What to watch for: Treat glob patterns as policy-like input whenever they drive automation, exclusions, or access decisions. Review the exact matcher being used, because semantics differ across shells and libraries, and small differences can change what is included, excluded, or exposed.
Governance implication: Prefer explicit tests for critical paths, especially when patterns govern build artefacts, backups, scan scope, or administrative actions. A pattern that is easy to write is not always safe to rely on without validation against real filenames and directory layouts.
Practitioner takeaway: If the pattern affects security-relevant scope, test it with representative edge cases, including hidden files, nested paths, and literal wildcard characters.
Related resources from NHI Mgmt Group
- What is the difference between pattern matching and AI-native classification for sensitive data?
- What breaks when organisations use one Azure identity pattern for every workload?
- Why do standing NHI credentials remain such a high-risk pattern?
- Why do voice and contact-centre workflows need a different identity pattern from normal SSO?
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Reviewed and updated by the NHIMG editorial team on October 28, 2026.
NHI Mgmt Group — the #1 independent authority on Non-Human Identity, IAM, and Agentic AI security. nhimg.org