http

Daylight v4.9
Release Date: 1 February 2008

Object Synopsis

http -- HTTP server object

Description

An HTTP object represents a server which communicates via HTTP, i.e., an httpd-like program. An HTTP object is created with dt_http_alloc(3) and supports HTTP/0.9 and HTTP/1.0 protocols. A request from a client (e.g., a browser) are received by the server (an HTTP object) using dt_http_get(3). Communication via HTTP has the great advantage of operating over a logical network which may be local to a machine, between machines on a LAN, or global in scope (World Wide Web). The HTTP object encapsulates this process.

Operation of HTTP objects are controlled via named properties which are set via dt_setinteger(3), dt_setstring(3), and dt_appendstring(3). Names for system-defined properties start with "htt_" and are listed below. The only property which is absolutely required is "htt_port" which is set to the value of the `port' argument of dt_alloc_http_server(3). All other property have sensible defaults, so a call to dt_alloc_http_server(3) with a valid 'port' argument will create a reasonable HTTP service.

READ-ONLY PROPERTIES

htt_date

The date & time of HTTP object allocation, e.g., Mon, 02 Dec 2002 07:40:03 GMT. The format conforms to RFC 822 & RFC 1123. For more information, see http://www.ietf.org/rfc/rfc822.txt and http://www.ietf.org/rfc/rfc1123.txt.

htt_status

The state of the HTTP service when a TRANSFER object is returned from dt_http_get(3) and will be one of following values:

DX_HTT_OK means a request has been received. The TRANSFER object will be equal to NULL_OB if the request was processed internally. Otherwise, the TRANSFER object will be a valid object for processing.

DX_HTT_TIMEOUT means a request has not been received. The TRANSFER object will be equal to NULL_OB.

DX_HTT_ERROR means an error condition exists. The TRANSFER object will be equal to NULL_OB. Use dt_errors(3) to access error information.

DX_HTT_DONE means the same as DX_HTT_OK and also indicates that the service has completed. This status is useful for breaking a CGI service from a dual-purpose Server/CGI loop. Calling dt_http_get(3) again will result in an error.

htt_port

The port number on which the service is listening. This value is equal to the argument passed to dt_alloc_http_server(3). Valid values are 0 to 65535 inclusive. Port 0 is interpreted as standard input and causes the service to behave as a CGI.

htt_host

The name of the local host as viewed from the server using the uname(1) system call, e.g., www.daylight.com.

htt_lips

The IP address of the local host as viewed from the server using gethostbyaddr(3) system call, e.g., 207.225.60.130.

READ_WRITE PROPERTIES

htt_timeout_ms

The time in milliseconds the service polls the listening port for a request by using the select(3) system call. In other words, this value determines how long a call to dt_http_get(3) will wait before returning NULL_OB and setting the htt_status property to DX_HTT_TIMEOUT.

htt_method_id

A bitwise OR of request method identifiers that are implemented by the service. If a request method received within a call to <TT>dt_http_get</TT> is not implemented, the toolkit will internally process the request with a "<FONT COLOR=red>501 Not Implemented</FONT>" response. This is useful for denying unwanted methods within the toolkit. Valid values for this property are:

>DX_HTT_METHOD_HEAD means the service implements the request method HEAD.

DX_HTT_METHOD_GET means the service implements the request method GET.

DX_HTT_METHOD_POST means the service implements the request method POST.

DX_HTT_METHOD_ALL is a bitwise OR of all of the above method identifiers.

DX_HTT_METHOD_ANY disables toolkit internal processing of unimplemented requests.

Object Synopsis

Description

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