/**
 * Check if string contains only whitespace characters.
 */
declare function isBlank(str: string): boolean;
/**
 * Check if value is a non-empty string.
 */
declare function isNonEmptyString(value: unknown): value is string;
/**
 * Check if value is a valid semantic version string.
 */
declare function isSemverString(value: unknown): value is string;
/**
 * Perform locale-aware string comparison.
 */
declare function localeCompare(x: string, y: string): number;
/**
 * Convert package name to lowercase.
 */
declare function lowerName(purl: {
    name: string;
}): void;
/**
 * Convert package namespace to lowercase.
 */
declare function lowerNamespace(purl: {
    namespace?: string | undefined;
}): void;
/**
 * Convert package version to lowercase.
 */
declare function lowerVersion(purl: {
    version?: string | undefined;
}): void;
/**
 * Replace all dashes with underscores in string.
 */
declare function replaceDashesWithUnderscores(str: string): string;
/**
 * Replace all underscores with dashes in string.
 */
declare function replaceUnderscoresWithDashes(str: string): string;
/**
 * Find the first command injection character in a string.
 * Like findInjectionCharCode but uses the narrower command injection set.
 * Returns the character code found, or -1.
 */
declare function findCommandInjectionCharCode(str: string): number;
/**
 * Find the first injection character in a string.
 * Returns the character code of the first dangerous character found, or -1.
 *
 * Uses charCode scanning for performance in hot paths. The check is a
 * single pass with no allocation, no regex, and no prototype method calls
 * beyond the captured StringPrototypeCharCodeAt primordial.
 *
 * Null bytes (0x00) are also caught by validateStrings() in validate.ts,
 * but we include them here for defense-in-depth so callers who skip the
 * base validators still get protection.
 */
declare function findInjectionCharCode(str: string): number;
/**
 * Check if string contains characters commonly used in injection attacks.
 * Returns true if any dangerous character is found.
 *
 * For detailed information about which character was found, use
 * {@link findInjectionCharCode} instead.
 */
declare function containsInjectionCharacters(str: string): boolean;
/**
 * Format an injection character code as a human-readable label for error messages.
 * Returns a string like `"|" (0x7c)` for printable chars or `0x1b` for control chars.
 */
declare function formatInjectionChar(code: number): string;
/**
 * Remove leading slashes from string.
 */
declare function trimLeadingSlashes(str: string): string;
export { containsInjectionCharacters, findCommandInjectionCharCode, findInjectionCharCode, formatInjectionChar, isBlank, isNonEmptyString, isSemverString, localeCompare, lowerName, lowerNamespace, lowerVersion, replaceDashesWithUnderscores, replaceUnderscoresWithDashes, trimLeadingSlashes, };