validate

func EncodePathSegment ¶

func EncodePathSegment(s string) string

EncodePathSegment percent-encodes user input for safe use as a single URL path segment (e.g. / → %2F, ? → %3F), ensuring the value cannot alter URL routing when interpolated into an API path.

func RejectCRLF ¶

func RejectCRLF(value, fieldName string) error

RejectCRLF rejects strings containing carriage return (\r) or line feed (\n). These characters enable MIME/HTTP header injection and must never appear in header values, filenames, or single-line parameters.

func RejectControlChars ¶

func RejectControlChars(value, flagName string) error

RejectControlChars rejects C0 control characters (except \t and \n) and dangerous Unicode characters from user input.

Control characters cause subtle security issues: null bytes truncate strings at the C layer, \r enables HTTP header injection via CRLF. Dangerous Unicode characters allow visual spoofing (e.g. making "admin" appear as a different string via Bidi overrides).

func ResourceName ¶

func ResourceName(name, flagName string) error

ResourceName validates an API resource identifier (userId, taskId, etc.) before it is interpolated into a URL path. It rejects path traversal (..), URL metacharacters (?#%), percent-encoded bypasses, control characters, and dangerous Unicode.

Without this check, an input like "../admin" or "?evil=true" in a resource ID would alter the API endpoint.

func SanitizeForTerminal ¶

func SanitizeForTerminal(text string) string

SanitizeForTerminal strips ANSI escape sequences, C0 control characters (except \n and \t), and dangerous Unicode from text. Apply to table-format output and stderr messages, but NOT to json output where consumers need raw data.

API responses may contain injected ANSI sequences that clear the screen, fake a colored "OK" status, or change the terminal title. In AI Agent scenarios, such injections can pollute the LLM's context window.

func StripQueryFragment ¶

func StripQueryFragment(path string) string

StripQueryFragment removes any ?query or #fragment suffix from a URL path. API parameters must go through structured flags, not embedded in the path, to prevent parameter injection.