# HTTP POST request **URL:** \ **Category:** Open AT\ **Created:** [May 5, 2009, 9:54am UTC](https://forum.sierrawireless.com/t/http-post-request/3185 "2009-05-05T09:54:43Z")\ **Posts on this page:** 4\ **Page:** 1
**Author:** ![njiterry](https://avatars.discourse-cdn.com/v4/letter/n/71c47a/32.png) [@njiterry](https://forum.sierrawireless.com/u/njiterry)\ **Post date:** [May 5, 2009, 9:54am UTC](https://forum.sierrawireless.com/t/http-post-request/3185/1 "2009-05-05T09:54:43Z")
I am trying trying to use HTTP POST to send data to our Vodafone server. I am supposed to send it in name/value pairs. We have two pairs(parameters) on our website date\_time and temp. Please find my code below: const ascii \* HTTP\_STR\_URL = “[http://weather.vodafonernd.com/post.php](http://weather.vodafonernd.com/post.php)”; static void http\_ClientTestDataHandler( wip\_event\_t \*ev, void _ctx) { ascii tmpbuf[160]; int BytesWritten, code; s32 status; ascii info[50]; /_ How many bytes of [tmpbuf] have already been sent. \*/ static int offset = 0; s16 m,n,p,w; m = (s16) GPIO26info\_t.TenMinTemp \* 10; // Decimal precision: 1 digit n = (GPIO26info\_t.TenMinTemp \* 10 ) - m; // Decimal precision: 1 digit p = (s16) GPIO26info\_t.TenMinHum \* 10; // Decimal precision: 1 digit w = (GPIO26info\_t.TenMinHum \* 10 ) - p; // Decimal precision: 1 digit wm\_sprintf(tmpbuf, “date\_time=%04lu-%02lu-%02lu%02lu:%02lu:%02lu&temp=%d.%01d”, GPStimedate\_t.year, GPStimedate\_t.month, GPStimedate\_t.day, GPStimedate\_t.hour, GPStimedate\_t.minute, GPStimedate\_t.seconds, (s16)GPIO26info\_t.TenMinTemp, n); switch(ev-\>kind) { case WIP\_CEV\_OPEN: TRACE(( 4, “http\_ClientTestDataHandler: WIP\_CEV\_OPEN\n” )); adl\_atSendResponsePort ( ADL\_AT\_RSP, ADL\_PORT\_UART1, “\r\nhttp\_ClientTestDataHandler: Start\r\n”); break; case WIP\_CEV\_READ: adl\_atSendResponsePort ( ADL\_AT\_RSP, ADL\_PORT\_UART1, “\r\nhttp\_ClientTestDataHandler: WIP\_CEV\_READ\r\n”); wip\_getOpts(http\_ClientTestCtx.DataChannel, WIP\_COPT\_HTTP\_STATUS\_CODE, &code, WIP\_COPT\_END); wm\_sprintf( info, “\r\nHTTP Status code: %d\r\n”, code); adl\_atSendResponsePort ( ADL\_AT\_RSP, ADL\_PORT\_UART1, info); if (code == 200){ wip\_close( http\_ClientTestCtx.DataChannel); wip\_close( http\_ClientTestCtx.CnxChannel); } break; ``` case WIP_CEV_WRITE: TRACE(( 4, "http_ClientTestDataHandler: WIP_CEV_WRITE\n" )); adl_atSendResponsePort ( ADL_AT_RSP, ADL_PORT_UART1, "\r\nhttp_ClientTestDataHandler: WIP_CEV_WRITE\r\n"); BytesWritten = wip_write( http_ClientTestCtx.DataChannel, tmpbuf, sizeof(tmpbuf)-offset); if(BytesWritten < 0) {/* error */ wip_debug( "HTTP write error %i\n", BytesWritten); adl_atSendResponse ( ADL_AT_UNS, "\r\nwip_write error\r\n" ); return; } offset += BytesWritten; /* Update the number of bytes sent. */ if( offset == sizeof( tmpbuf)) { /* All of [buffer] has been sent */ TRACE(( 4, "http_ClientTestDataHandler: bytes %d written\n", offset )); wm_sprintf( info, "\r\nhttp_ClientTestDataHandler: %d bytes written\r\n", offset); adl_atSendResponsePort ( ADL_AT_RSP, ADL_PORT_UART1, info); } wip_shutdown( http_ClientTestCtx.DataChannel,FALSE,TRUE); break; case WIP_CEV_PEER_CLOSE: TRACE(( 4, "http_ClientTestDataHandler: WIP_CEV_PEER_CLOSE\n" )); adl_atSendResponse ( ADL_AT_UNS, "\r\nhttp_ClientTestDataHandler: Done\r\n" ); // end of data // show response information if( wip_getOpts( ev->channel, WIP_COPT_HTTP_STATUS_CODE, &status, WIP_COPT_HTTP_STATUS_REASON, tmpbuf, sizeof(tmpbuf), WIP_COPT_END) == OK) { ascii sbuf[16]; adl_atSendResponse ( ADL_AT_UNS, "http_ClientTestDataHandler: Status=" ); wm_sprintf( sbuf, "%d", status); adl_atSendResponse ( ADL_AT_UNS, sbuf); adl_atSendResponse ( ADL_AT_UNS, "\r\nhttp_ClientTestDataHandler: Reason=\"" ); adl_atSendResponse ( ADL_AT_UNS, tmpbuf); adl_atSendResponse ( ADL_AT_UNS, "\"\r\n" ); TRACE(( 4, "http_ClientTestDataHandler: Status=%d\n", status)); TRACE(( 4, "http_ClientTestDataHandler: Reason=\"%s\"\n", tmpbuf)); } if( wip_getOpts( ev->channel, WIP_COPT_HTTP_HEADER, "content-type", tmpbuf, sizeof(tmpbuf), WIP_COPT_END) == OK) { TRACE(( 4, "http_ClientTestDataHandler: Content Type=\"%s\"\n", tmpbuf)); } TRACE(( 4, "http_ClientTestDataHandler: Response Length=%d bytes\n", pHttpClientCtx->dataLength )); // data channel must be closed wip_close( ev->channel); break; case WIP_CEV_ERROR: TRACE(( 2, "http_ClientTestDataHandler: WIP_CEV_ERROR %d\n", ev->content.error.errnum)); //adl_atSendResponse ( ADL_AT_UNS, "http_ClientTestDataHandler: ERROR\r\n" ); adl_atSendResponsePort ( ADL_AT_RSP, ADL_PORT_UART1, "\r\nhttp_ClientTestDataHandler: ERROR\r\n"); // connection to server broken wip_close( ev->channel); break; default: TRACE(( 2, "http_ClientTestDataHandler: unexpected event: %d\n", ev->kind)); adl_atSendResponsePort ( ADL_AT_RSP, ADL_PORT_UART1, "\r\nunexpected event\r\n"); break; ``` } } static s32 http\_Client(void) { s32 ret = 0; ``` // HTTP Session creation // --------------------------- http_ClientTestCtx.CnxChannel = wip_HTTPClientCreateOpts( NULL, // no handler NULL, // no context // default headers WIP_COPT_HTTP_HEADER, "User-Agent", "HTTP/1.1", WIP_COPT_END); if (http_ClientTestCtx.CnxChannel == NULL) { TRACE(( 2, "cannot create http session channel\n" )); //adl_atSendResponse ( ADL_AT_UNS, "cannot create http session channel\r\n" ); adl_atSendResponsePort ( ADL_AT_RSP, ADL_PORT_UART1, "\r\ncannot create http session channel\r\n"); ret = -1; } else { adl_atSendResponsePort ( ADL_AT_RSP, ADL_PORT_UART1, "\r\nhttp session channel created\r\n"); // HTTP POST command http_ClientTestCtx.DataChannel = wip_getFileOpts( http_ClientTestCtx.CnxChannel, // session channel HTTP_STR_URL, // URL to receive the data http_ClientTestDataHandler, // data handler &http_ClientTestCtx, // context WIP_COPT_HTTP_METHOD, WIP_HTTP_METHOD_POST, // request headers WIP_COPT_HTTP_HEADER, "Content-Type", "application/x-www-form-urlencoded", WIP_COPT_HTTP_HEADER, "Content-Length", 160, WIP_COPT_HTTP_HEADER, "Accept", "text/html", WIP_COPT_END); if (http_ClientTestCtx.DataChannel == NULL) { TRACE(( 2, "cannot create http data channel\n" )); adl_atSendResponsePort ( ADL_AT_RSP, ADL_PORT_UART1, "\r\ncannot create http data channel\r\n"); wip_close( http_ClientTestCtx.CnxChannel); // ret =-1; } else adl_atSendResponsePort ( ADL_AT_RSP, ADL_PORT_UART1, "\r\nHTTP data channel created\r\n"); } return(ret); ``` } I get the following traces/responses and the data is not posted on our server. http session channel created [HTTP] new request GET [weather.vodafonernd.com/post.php](http://weather.vodafonernd.com/post.php) HTTP/1.1 @ 180ed12020 [HTTP] connect to host: [weather.vodafonernd.com:80](http://weather.vodafonernd.com:80) HTTP data channel created http\_ClientTestDataHandler: Start http\_ClientTestDataHandler: WIP\_CEV\_WRITE http\_ClientTestDataHandler: 160 bytes written http\_ClientTestDataHandler: WIP\_CEV\_READ HTTP Status code: 400 The status code 400 means my request is bad or has a wrong syntax. Please what is wrong with my syntax? how should i sent the reqeust message so that the server receives the name/value pairs ? ---
**Author:** ![maly\_co](https://avatars.discourse-cdn.com/v4/letter/m/3e96dc/32.png) [@maly\_co](https://forum.sierrawireless.com/u/maly_co)\ **Post date:** [May 17, 2009, 12:14am UTC](https://forum.sierrawireless.com/t/http-post-request/3185/2 "2009-05-17T00:14:45Z")
I don’t know if this header id is good: WIP\_COPT\_HTTP\_HEADER, “Content-Length”, 160, - maybe you should replace 160 to a string. ---
**Author:** ![davidc](https://avatars.discourse-cdn.com/v4/letter/d/a183cd/32.png) [@davidc](https://forum.sierrawireless.com/u/davidc)\ **Post date:** [May 17, 2009, 7:35am UTC](https://forum.sierrawireless.com/t/http-post-request/3185/3 "2009-05-17T07:35:18Z")
Hiya, > [@njiterry](#): > > Please what is wrong with my syntax? how should i sent the reqeust message so that the server receives the name/value pairs A : (colon) is not permitted in a POST field. This character also needs to be URL encoded ( %3A ). However, a - (dash) seems to be OK. > [@njiterry](#): > > wm\_sprintf(tmpbuf, “date\_time=%04lu-%02lu-%02lu%02lu:%02lu:%02lu&temp=%d.%01d”, I’ve done a quick count of your data request: ```auto [10] date_time= [4] %04lu [1] - [2] %02lu [2] %02lu [1] : [2] %02lu [6] &temp= [??] %d [1] . [1] %01d ``` This adds up to 30 characters (not counting [??] and not expanding the colon into %3A). The Content-Length: has to be the exact length of the URL encoded data in the request…or the server will barf on your data. Note that the field %d is going to be an indeterminate length, depending on the value of your variable - which will make using a fixed value for your header a little bit harder. You are probably better using %04d to ensure that the value is always the same length (as you did with the date and time fields). My final comment is that you are probably better building the content buffer before you start the HTTP POST event, rather than in the top of the event handler as you are doing at the moment. That way, you can build your content header along the following lines: ```auto static s32 http_Client( void ) { ascii tmpbuf[160]; ascii contentHdrBuf[10]; // set up session etc // create outgoing data buffer wm_sprintf(tmpbuf, ""); // as per your existing code // create content length header wm_sprintf(contentHdrBuf, "%d", wm_strlen(tmpbuf)); // create POST request http_ClientTestCtx.DataChannel = wip_getFileOpts( http_ClientTestCtx.CnxChannel, // session channel HTTP_STR_URL, // URL to receive the data http_ClientTestDataHandler, // data handler &http_ClientTestCtx, // context WIP_COPT_HTTP_METHOD, WIP_HTTP_METHOD_POST, // request headers WIP_COPT_HTTP_HEADER, "Content-Type", "application/x-www-form-urlencoded", WIP_COPT_HTTP_HEADER, "Content-Length", contentHdrBuf, WIP_COPT_HTTP_HEADER, "Accept", "text/html", WIP_COPT_END); // continue processing ``` Hope this helps. ciao, Dave P.S. Please use the [code] tags next time you insert code into a forum post. It keeps all your formatting - and makes it easier for the rest of us to read 😃 . ---
**Author:** ![peter\_mcc](https://avatars.discourse-cdn.com/v4/letter/p/6a8cbe/32.png) [@peter\_mcc](https://forum.sierrawireless.com/u/peter_mcc)\ **Post date:** [July 17, 2009, 4:00am UTC](https://forum.sierrawireless.com/t/http-post-request/3185/4 "2009-07-17T04:00:20Z")
> [@maly\_co](#): > > I don’t know if this header id good: WIP\_COPT\_HTTP\_HEADER, “Content-Length”, 160, - maybe you should replace 160 to a string. This just caught me out - the 160 is missing double quotes. So the line should be ```auto WIP_COPT_HTTP_HEADER, "Content-Length", "160" ```