Apache: The Definitive Guide, 3rd Edition

Status Codes

The HTTP 1.1 standard defines many status codes that can be returned as a response to a request. Most of the functions involved in processing a request return OK, DECLINED, or a status code. DECLINED generally means that the module is not interested in processing the request; OK means it did process it, or that it is happy for the request to proceed, depending on which function was called. Generally, a status code is simply returned to the user agent, together with any headers defined in the request structure’s headers_out table. At the time of writing, the status codes predefined in httpd.h were as follows:

#define HTTP_CONTINUE 100 #define HTTP_SWITCHING_PROTOCOLS 101 #define HTTP_OK 200 #define HTTP_CREATED 201 #define HTTP_ACCEPTED 202 #define HTTP_NON_AUTHORITATIVE 203 #define HTTP_NO_CONTENT 204 #define HTTP_RESET_CONTENT 205 #define HTTP_PARTIAL_CONTENT 206 #define HTTP_MULTIPLE_CHOICES 300 #define HTTP_MOVED_PERMANENTLY 301 #define HTTP_MOVED_TEMPORARILY 302 #define HTTP_SEE_OTHER 303 #define HTTP_NOT_MODIFIED 304 #define HTTP_USE_PROXY 305 #define HTTP_BAD_REQUEST 400 #define HTTP_UNAUTHORIZED 401 #define HTTP_PAYMENT_REQUIRED 402 #define HTTP_FORBIDDEN 403 #define HTTP_NOT_FOUND 404 #define HTTP_METHOD_NOT_ALLOWED 405 #define HTTP_NOT_ACCEPTABLE 406 #define HTTP_PROXY_AUTHENTICATION_REQUIRED 407 #define HTTP_REQUEST_TIME_OUT 408 #define HTTP_CONFLICT 409 #define HTTP_GONE 410 #define HTTP_LENGTH_REQUIRED 411 #define HTTP_PRECONDITION_FAILED 412 #define ...