This function allows the service program to control the HTTP status that is returned with a response. By default, the response status will be 200, which is an HTTP status of OK. However, if it is desirable to return a different status, this function may be used to alter the status for the next response. Subsequent responses return OK again unless B$SetResponseStatus is called before B$WriteResponse.
The syntax of this function call is:
Call "B$SetResponseStatus" using ResponseStatus giving BIS-Status.
where ResponseStatus may be:
| Status Code | Status Name | HTTP Standard Description |
|---|---|---|
| 1xx | Informational | This class of status code indicates a provisional response, consisting only of the Status-Line and optional headers, and
is terminated by an empty line. There are no required headers for this class of status code.
A client must be prepared to accept one or more 1xx status responses prior to a regular response, even if the client does not expect a 100 (Continue) status message. Unexpected 1xx status responses may be ignored by a user agent. |
| 100 | Informational | The client should continue with its request. This interim response is used to inform the client that the initial part of the
request has been received and has not yet been rejected by the server. The client should continue by sending the remainder
of the request or, if the request has already been completed, ignore this response. The server must send a final response
after the request has been completed.
This status code is generated by the web server directly and should not be returned by the service program. |
| 101 | Switching Protocols | The server understands and is willing to comply with the client's request, via the Upgrade message header field, for a change
in the application protocol being used on this connection. The server will switch protocols to those defined by the response's
Upgrade header field immediately after the empty line which terminates the
101 response.
This status code is generated by the web server directly and should not be returned by the service program. |
| 2xx | Successful | This class of status code indicates that the client's request was successfully received, understood, and accepted. |
| 200 | OK | The request has succeeded. The information returned with the response is dependent on the method used in the request. |
| 201 | Created | The request has been fulfilled and resulted in a new resource being created. The newly created resource can be referenced by the URI(s) returned in the entity of the response, with the most specific URI for the resource given by a Location header field. The response should include an entity containing a list of resource characteristics and location(s) from which the user or user agent can choose the one most appropriate. The entity format is specified by the media type given in the Content-Type header field. The origin server must create the resource before returning the 201 status code. If the action cannot be carried out immediately, the server should respond with 202 (Accepted) response instead. |
| 202 | Accepted | The request has been accepted for processing, but the processing has not been completed. The request might or might not eventually
be acted upon, as it might be disallowed when processing actually takes place. There is no facility for resending a status
code from an asynchronous operation such as this.
The 202 response is intentionally non-committal. Its purpose is to allow a server to accept a request for some other process (perhaps a batch-oriented process that is only run once per day) without requiring that the user agent's connection to the server persist until the process is completed. The entity returned with this response should include an indication of the request's current status and either a pointer to a status monitor or some estimate of when the user can expect the request to be fulfilled. |
| 203 | Non-Authoritative Information | The returned meta information in the entity-header is not the definitive set as available from the origin server, but is gathered from a local or a third-party copy. The set presented may be a subset or superset of the original version. For example, including local annotation information about the resource might result in a superset of the meta information known by the origin server. Use of this response code is not required and is only appropriate when the response would otherwise be 200 (OK). |
| 204 | No Content | The server has fulfilled the request but does not need to return an entity-body, and might want to return updated meta information.
The response may include new or updated meta information in the form of entity-headers, which if present should be associated
with the requested variant.
If the client is a user agent, it should not change its document view from that which caused the request to be sent. This response is primarily intended to allow input for actions to take place without causing a change to the user agent's active document view, although any new or updated metadata should be applied to the document currently in the user agent's active view. The 204 response must not include a message-body, and thus is always terminated by the first empty line after the header fields. |
| 205 | Reset Content | The server has fulfilled the request and the user agent should reset the document view which caused the request to be sent. This response is primarily intended to allow input for actions to take place via user input, followed by a clearing of the form in which the input is given so that the user can easily initiate another input action. The response must not include an entity. |
| 206 | Partial Content | The server has fulfilled the partial GET request for the resource. |
| 3xx | Redirection | This class of status code indicates that further action needs to be taken by the user agent in order to fulfill the request. The action required may be carried out by the user agent without interaction with the user if and only if the method used in the second request is GET or HEAD. A client should detect infinite redirection loops, since such loops generate network traffic for each redirection. |
| 300 | Multiple Choices | The requested resource corresponds to any one of a set of representations, each with its own specific location, and agent-
driven negotiation information is being provided so that the user (or user agent) can select a preferred representation and
redirect its request to that location.
Unless it was a HEAD request, the response should include an entity containing a list of resource characteristics and location(s) from which the user or user agent can choose the one most appropriate. The entity format is specified by the media type given in the Content-Type header field. Depending upon the format and the capabilities of the user agent, selection of the most appropriate choice may be performed automatically. However, this specification does not define any standard for such automatic selection. If the server has a preferred choice of representation, it should include the specific URI for that representation in the Location field; user agents may use the Location field value for automatic redirection. This response can be cached unless otherwise indicated. |
| 301 | Moved Permanently | The requested resource has been assigned a new permanent URI and any future references to this resource should use one of
the returned URIs. Clients with link editing capabilities ought to automatically re-link references to the Request-URI to
one or more of the new references returned by the server, where possible. This response can be cached unless otherwise indicated.
The new permanent URI should be given by the Location field in the response. Unless the request method was HEAD, the entity of the response should contain a short hypertext note with a hyperlink to the new URI(s). If the 301 status code is received in response to a request other than GET or HEAD, the user agent must not automatically redirect the request unless it can be confirmed by the user, since this might change the conditions under which the request was issued. |
| 302 | Found | The requested resource resides temporarily under a different URI. Since the redirection might be altered on occasion, the
client should continue to use the Request-URI for future requests. This response can only be cached if indicated by a Cache-Control
or Expires header field.
The temporary URI should be given by the Location field in the response. Unless the request method was HEAD, the entity of the response should contain a short hypertext note with a hyperlink to the new URI(s). If the 302 status code is received in response to a request other than GET or HEAD, the user agent must not automatically redirect the request unless it can be confirmed by the user, since this might change the conditions under which the request was issued. |
| 303 | See Other | The response to the request can be found under a different URI and should be retrieved using a GET method on that resource.
This method exists primarily to allow the output of a POST-activated script to redirect the user agent to a selected resource.
The new URI is not a substitute reference for the originally requested resource. The
303 response must not be cached, but the response to the second (redirected) request may be cached.
The different URI should be given by the Location field in the response. Unless the request method was HEAD, the entity of the response should contain a short hypertext note with a hyperlink to the new URI(s). |
| 304 | Not Modified | If the client has performed a conditional GET request and access is allowed, but the document has not been modified, the server should respond with this status code. The 304 response must not contain a message-body, and thus is always terminated by the first empty line after the header fields. |
| 305 | Use Proxy | The requested resource must be accessed through the proxy given by the Location field. The Location field gives the URI of the proxy. The recipient is expected to repeat this single request via the proxy. 305 responses must only be generated by origin servers. |
| 306 | (unused) | The 306 status code was used in a previous version of the specification, is no longer used, and the code is reserved. |
| 307 | Temporary Redirect | The requested resource resides temporarily under a different URI. Since the redirection may be altered on occasion, the client
should continue to use the Request-URI for future requests. This response can only be cached if indicated by a Cache-Control
or Expires header field.
The temporary URI should be given by the Location field in the response. Unless the request method was HEAD, the entity of the response should contain a short hypertext note with a hyperlink to the new URI(s) , since many pre-HTTP/1.1 user agents do not understand the 307 status. Therefore, the note should contain the information necessary for a user to repeat the original request on the new URI. If the 307 status code is received in response to a request other than GET or HEAD, the user agent must not automatically redirect the request unless it can be confirmed by the user, since this might change the conditions under which the request was issued. |
| 4xx | Client Error | The
4xxclass of status code is intended for cases in which the client seems to have erred. Except when responding to a HEAD request,
the server should include an entity containing an explanation of the error situation, and whether it is a temporary or permanent
condition. These status codes are applicable to any request method. User agents should display any included entity to the
user.
If the client is sending data, a server implementation using TCP should be careful to ensure that the client acknowledges receipt of the packet(s) containing the response, before the server closes the input connection. If the client continues sending data to the server after the close, the server's TCP stack will send a reset packet to the client, which may erase the client's unacknowledged input buffers before they can be read and interpreted by the HTTP application. |
| 400 | Bad Request | The request could not be understood by the server due to malformed syntax. The client should not repeat the request without modifications. |
| 401 | Unauthorized | The request requires user authentication. The response must include a WWW-Authenticate header field containing a challenge applicable to the requested resource. The client may repeat the request with a suitable Authorization header field. If the request already included Authorization credentials, then the 401 response indicates that authorization has been refused for those credentials. If the 401 response contains the same challenge as the prior response, and the user agent has already attempted authentication at least once, then the user should be presented the entity that was given in the response, since that entity might include relevant diagnostic information. |
| 402 | Payment Required | This code is reserved for future use. |
| 403 | Forbidden | The server understood the request, but is refusing to fulfill it. Authorization will not help and the request should not be repeated. If the request method was not HEAD and the server wishes to make public why the request has not been fulfilled, it should describe the reason for the refusal in the entity. If the server does not wish to make this information available to the client, the status code 404 (Not Found) can be used instead. |
| 404 | Not Found | The server has not found anything matching the Request-URI. No indication is given of whether the condition is temporary or permanent. The 410 (Gone) status code should be used if the server knows, through some internally configurable mechanism, that an old resource is permanently unavailable and has no forwarding address. This status code is commonly used when the server does not wish to reveal exactly why the request has been refused, or when no other response is applicable. |
| 405 | Method Not Allowed | The method specified in the Request-Line is not allowed for the resource identified by the Request-URI. The response must include an Allow header containing a list of valid methods for the requested resource. |
| 406 | Not Acceptable | The resource identified by the request is only capable of generating response entities which have content characteristics
not acceptable according to the accept headers sent in the request.
Unless it was a HEAD request, the response should include an entity containing a list of available entity characteristics and location(s) from which the user or user agent can choose the one most appropriate. The entity format is specified by the media type given in the Content-Type header field. Depending upon the format and the capabilities of the user agent, selection of the most appropriate choice may be performed automatically. However, this specification does not define any standard for such automatic selection. If the response could be unacceptable, a user agent should temporarily stop receipt of more data and query the user for a decision on further actions. |
| 407 | Proxy Authentication Required | This code is similar to 401 (Unauthorized), but indicates that the client must first authenticate itself with the proxy. The proxy must return a Proxy-Authenticate header field containing a challenge applicable to the proxy for the requested resource. The client may repeat the request with a suitable Proxy-Authorization header field. |
| 408 | Request Timeout | The client did not produce a request within the time that the server was prepared to wait. The client may repeat the request without modifications at any later time. |
| 409 | Conflict | The request could not be completed due to a conflict with the current state of the resource. This code is only allowed in
situations where it is expected that the user might be able to resolve the conflict and resubmit the request. The response
body should include enough information for the user to recognize the source of the conflict. Ideally, the response entity
would include enough information for the user or user agent to fix the problem; however, that might not be possible and is
not required.
Conflicts are most likely to occur in response to a PUT request. For example, if versioning were being used and the entity being PUT included changes to a resource which conflict with those made by an earlier (third-party) request, the server might use the 409 response to indicate that it can't complete the request. In this case, the response entity would likely contain a list of the differences between the two versions in a format defined by the response Content-Type. |
| 410 | Gone | The requested resource is no longer available at the server and no forwarding address is known. This condition is expected
to be considered permanent. Clients with link editing capabilities should delete references to the Request-URI after user
approval. If the server does not know, or has no facility to determine, whether or not the condition is permanent, the status
code
404 (Not Found) should be used instead. This response can be cached unless indicated otherwise.
The 410 response is primarily intended to assist the task of web maintenance by notifying the recipient that the resource is intentionally unavailable and that the server owners desire that remote links to that resource be removed. Such an event is common for limited-time, promotional services and for resources belonging to individuals no longer working at the server's site. It is not necessary to mark all permanently unavailable resources as gone or to keep the mark for any length of time -- that is left to the discretion of the server owner. |
| 411 | Length Required | The server refuses to accept the request without a defined Content- Length. The client may repeat the request if it adds a valid Content-Length header field containing the length of the message-body in the request message. |
| 412 | Precondition Failed | The precondition given in one or more of the request-header fields evaluated to false when it was tested on the server. This response code allows the client to place preconditions on the current resource meta information (header field data) and thus prevent the requested method from being applied to a resource other than the one intended. |
| 413 | Request Entity Too Large | The server is refusing to process a request because the request entity is larger than the server is willing or able to process.
The server may close the connection to prevent the client from continuing the request.
If the condition is temporary, the server should include a Retry- After header field to indicate that it is temporary and after what time the client may try again. |
| 414 | Request-URI Too Long | The server is refusing to service the request because the Request-URI is longer than the server is willing to interpret. This rare condition is only likely to occur when a client has improperly converted a POST request to a GET request with long query information, when the client has descended into a URI black hole of redirection (e.g., a redirected URI prefix that points to a suffix of itself), or when the server is under attack by a client attempting to exploit security holes present in some servers using fixed-length buffers for reading or manipulating the Request-URI. |
| 415 | Unsupported Media Type | The server is refusing to service the request because the entity of the request is in a format not supported by the requested resource for the requested method. |
| 416 | Requested Range Not Satisfiable | A server should return a response with this status code if a request included a Range request-header field, and none of the
range-specifier values in this field overlap the current extent of the selected resource, and the request did not include
an If-Range request-header field. (For byte-ranges, this means that the first- byte-pos of all of the byte-range-spec values
were greater than the current length of the selected resource.)
When this status code is returned for a byte-range request, the response should include a Content-Range entity-header field specifying the current length of the selected resource. This response must not use the multi-part/byteranges content-types. |
| 417 | Expectation Failed | The expectation given in an Expect request-header field could not be met by this server, or, if the server is a proxy, the server has unambiguous evidence that the request could not be met by the next-hop server. |
| 5xx | Server Error | Response status codes beginning with the digit
5 indicate cases in which the server is aware that it has erred or is incapable of performing the request. Except when responding
to a HEAD request, the server should include an entity containing an explanation of the error situation, and whether it is
a temporary or permanent condition. User agents should display any included entity to the user. These response codes are applicable
to any request method.
In general, these error codes are generated by HTTP server itself, and the service program should not use them. |
| 500 | Internal Server Error | The server encountered an unexpected condition which prevented it from fulfilling the request. |
| 501 | Not Implemented | The server does not support the functionality required to fulfill the request. This is the appropriate response when the server does not recognize the request method and is not capable of supporting it for any resource. |
| 502 | Bad Gateway | The server, while acting as a gateway or proxy, received an invalid response from the upstream server it accessed in attempting to fulfill the request. |
| 503 | Service Unavailable | The server is currently unable to handle the request due to a temporary overloading or maintenance of the server. The implication is that this is a temporary condition which will be alleviated after some delay. If known, the length of the delay may be indicated in a Retry-After header. If no Retry-After is given, the client should handle the response as it would for a 500 response. |
| 504 | Gateway Timeout | The server, while acting as a gateway or proxy, did not receive a timely response from the upstream server specified by the URI (e.g. HTTP, FTP, LDAP) or some other auxiliary server (e.g. DNS) it needed to access in attempting to complete the request. |
| 505 | HTTP Version Not Supported | The server does not support, or refuses to support, the HTTP protocol version that was used in the request message. The server is indicating that it is unable or unwilling to complete the request using the same major version as the client, other than with this error message. The response should contain an entity describing why that version is not supported and what other protocols are supported by that server. |
The BIS-Status result field and the result codes are defined in BISDEF.CPY. Here are the most common return codes:
| BIS-Status Code | Event Description |
|---|---|
| BIS-Success | The call was successful. |