REGEXVAULTv2.0
Dev & Systems/Environment
Verified Safe

POSIX Environment Variable Name (Uppercase Convention) Regex for Go

/^[A-Z_][A-Z0-9_]{0,254}$/

What this pattern does

This page provides a lightweight, single-purpose regular expression for matching posix environment variable name (uppercase convention), ported and verified for Go. A rigorously tested regex reduces debugging time and protects your application from edge-case failures. The snippet below is ready to drop into your Go project — whether you're validating in a Gin handler, a gRPC service, or a command-line tool.

Go Implementation

Go
// POSIX Environment Variable Name (Uppercase Convention)
// ReDoS-safe | RegexVault — Dev & Systems > Environment

package validation

import "regexp"

var posixEnvironmentVariableNameUppercaseConventionRe = regexp.MustCompile(`^[A-Z_][A-Z0-9_]{0,254}$`)

func ValidatePosixEnvironmentVariableNameUppercaseConvention(s string) bool {
    return posixEnvironmentVariableNameUppercaseConventionRe.MatchString(s)
}

// Example
// fmt.Println(ValidatePosixEnvironmentVariableNameUppercaseConvention("PATH")) // true

Test Cases

Matches (Valid)
Rejects (Invalid)
PATH1VAR
HOMEvar-name
NODE_ENVVAR NAME
_PRIVATEVAR.NAME
DATABASE_URL_2
AWS_ACCESS_KEY_ID

When to use this pattern

This pattern is drawn from the Dev & Systems > Environment category and carries a ReDoS-safe certification. That matters for Go developers because Go's RE2 engine is inherently safe from catastrophic backtracking, but this pattern has been additionally verified for correctness. RegexVault audits patterns against known backtracking attack vectors, ensuring you have the necessary context before using this regex in a high-stakes production environment.

Common Pitfalls

Lowercase variable names like 'path' are valid POSIX but shadow uppercase PATH. Normalize expected variable names to uppercase in cross-platform code.

Technical Notes

POSIX variables are case-sensitive and conventionally uppercase. Lowercase variables (PATH vs path) are different on Linux. On Windows, environment variables are case-insensitive.

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