WebTcpipRecvUntil Function

Action

Retrieves a response from the remote host until the pattern sPattern is found. Only the first nMaxData bytes are stored into the buffer sData. If sData is set to NULL, internal buffers are used for retrieval.

Include file

WebAPI.bdh

Syntax

WebTcpipRecvUntil( in  hWeb      : number,
                   out sData     : string allownull,
                   in  nMaxData  : number,
                   out nReceived : number allownull,
                   in  sPattern  : string,
                   in  nLength   : number optional ): boolean;

Return value

true if the end of response is found
false otherwise

Parameter	Description
hWeb	Valid handle to a Web connection that was created by WebTcpipConnect
sData	Buffer to store the received data. This field also can be set to NULL to use only internal buffers, for example, if data is not to be parsed
nMaxData	Maximum amount of bytes to store into sData. Specify STRING_COMPLETE to get all received data. This value has no effect when sData is set to NULL.
nReceived	Parameter that receives the actual amount of data received from the server
sPattern	The termination string. Predefined constants are: WEB_CRLF ("\r\n") WEB_CRLFCRLF ( "\r\n\r\n") WEB_CRLFDOTCRLF ("\r\n.\r\n") WEB_CRNULL ("\h0D00") WEB_LFNULL ("\h0A00") This may also be binary data. For using all available binary data specify STRING_COMPLETE for nLength and use the bin() operator for sData (see example).
nLength	The length of the binary pattern (optional). Omit this parameter to use all available data.

Example

dcltrans
  transaction TWeb
  var
    hWeb      : number;
    sHdr      : string;
    sSize     : string(20);
    nReceived : number;
    sPattern  : string;
  begin
    WebTcpipConnect(hWeb, "lab3", 80);
    sHdr := "GET /file5k.html HTTP/1.1\r\n"
                 "Host: lab3\r\n\r\n";
    
    // send HTTP request header
    WebTcpipSend(hWeb, sHdr);

    // receive HTTP response header
    WebTcpipRecvUntil(hWeb, sHdr, STRING_COMPLETE, nReceived, "\r\n\r\n");
    SPattern := "\r\n";
    WebTcpipRecvUntil(hWeb, sHdr, STRING_COMPLETE, nReceived, "\r\n\r\n");
 
    // receive document
    StrSearchDelimited(sSize, STRING_COMPLETE, sHdr, "Content-Length: ", 1, "\r\n",
                      1, STR_SEARCH_FIRST);
    WebTcpipRecvExact(hWeb, NULL, number(sSize));

    // reset the persistent connection
    WebTcpipShutdown(hWeb, WEB_SHUTDOWN_RESET);
  end TWeb;

Sample scripts

WebTcpipHttp01.bdf, WebTcpipImap401.bdf