Pattern

Regex for Docker volume mount

Docker -v host:container[:options] format.

The Docker volume mount regex is ^[^:]+:[^:]+(:(ro|rw|z|Z|cached|delegated|consistent))?$ — copy it below, or open it in the explainer for a token-by-token breakdown.

The pattern

^[^:]+:[^:]+(:(ro|rw|z|Z|cached|delegated|consistent))?$

Open in explainer → Download cheat sheet ↓

Token-by-token breakdown

Every part of the pattern, left to right:

Token	Meaning
`^`	start of string (or line in multiline mode)
`[^:]+`	one or more: any character except “:”
`:`	literal text “:”
`[^:]+`	one or more: any character except “:”
`(`	start of a capturing group
`:`	literal text “:”
`(`	start of a capturing group
`ro`	literal text “ro”
`\|`	OR — try the alternative
`rw`	literal text “rw”
`\|`	OR — try the alternative
`z`	literal text “z”
`\|`	OR — try the alternative
`Z`	literal text “Z”
`\|`	OR — try the alternative
`cached`	literal text “cached”
`\|`	OR — try the alternative
`delegated`	literal text “delegated”
`\|`	OR — try the alternative
`consistent`	literal text “consistent”
`)`	end of group
`)?`	end of group, optional (zero or one)
`$`	end of string (or line in multiline mode)

About this pattern

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

Quick usage in different languages

This exact pattern — with the correct escaping and idioms for each language:

JavaScript: /^[^:]+:[^:]+(:(ro|rw|z|Z|cached|delegated|consistent))?$/.test(value)
Python: re.match(r"^[^:]+:[^:]+(:(ro|rw|z|Z|cached|delegated|consistent))?$", value)
Java: Pattern.compile("^[^:]+:[^:]+(:(ro|rw|z|Z|cached|delegated|consistent))?$").matcher(value).matches()
C# / .NET: Regex.IsMatch(value, @"^[^:]+:[^:]+(:(ro|rw|z|Z|cached|delegated|consistent))?$")
Go: regexp.MustCompile(`^[^:]+:[^:]+(:(ro|rw|z|Z|cached|delegated|consistent))?$`).MatchString(value)
Ruby: /^[^:]+:[^:]+(:(ro|rw|z|Z|cached|delegated|consistent))?$/.match?(value)
PHP: preg_match('~^[^:]+:[^:]+(:(ro|rw|z|Z|cached|delegated|consistent))?$~', $value)

The explainer’s Code tab regenerates these for any pattern you paste, and the downloadable cheat sheet bundles the breakdown, all seven snippets, and the pitfalls below onto one printable page.

Common pitfalls

Anchored to the whole string. This pattern uses ^ and $, so it requires the entire input to match. To find it inside a longer text, drop the anchors and use the global (g) flag.
Validate beyond format. Matching the format doesn't guarantee the value is real. Confirm the docker volume mount against a source of truth (database, API, or checksum) where it matters.

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