Pattern

Regex for File path (Unix)

Absolute or relative Unix-style file path.

The pattern

^(?:\/|\.{1,2}\/)?(?:[\w.-]+\/)*[\w.-]+$

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What it matches

/usr/local/bin/python
./script.sh
../config/app.yml
file.txt

What it doesn't match

C:\Users\bob
path with spaces
/leading/space

Notes & gotchas

Doesn't allow spaces in path components. For paths with spaces, allow them in the character class. Doesn't check the file exists.

Code in your language

Use the explainer's Code tab to generate ready-to-paste snippets in JavaScript, Python, Java, .NET, Go, Ruby, and PHP for this pattern.

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About this pattern

Developer-oriented patterns help with code analysis, log parsing, and data transformation. Use these in build scripts, CI tools, and code review utilities.

Quick usage in different languages

Once you've validated a candidate value matches this pattern, you'll typically use it inside your application code. Each language has its own regex syntax:

JavaScript: new RegExp(pattern).test(value)
Python: re.match(pattern, value) with raw strings: r"pattern"
Java: Pattern.compile(pattern).matcher(value).matches()
C# / .NET: Regex.IsMatch(value, pattern)
Go: regexp.MustCompile(pattern).MatchString(value) — Go uses RE2 so some advanced features aren't available
Ruby: value =~ /pattern/ or pattern.match?(value)
PHP: preg_match('/pattern/', $value)

The explainer's Code tab generates these for any pattern you paste — including the right escaping and idioms for each language.

Common pitfalls

Anchors matter. If the pattern uses ^ and $ it expects the entire input to match. To find this pattern inside a longer text, remove the anchors and use the /g flag.
Case sensitivity. Letter ranges like [A-Z] only match uppercase. Use the i flag or [A-Za-z] for case-insensitive matching.
Escape user input. If you're building a regex from a string variable, escape regex metacharacters first to avoid bugs or injection.
Performance. For this specific pattern the risk is low, but be cautious of nested quantifiers when adapting it — they can cause exponential backtracking on adversarial input.