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Multiple request version for showtags.c

From: Michael Qiu <michael@atlas-china.com>
Date: Mon, 17 Feb 2003 14:19:44 +0800
Message-ID: <000501c2d64c$91b1c380$1c01a8c0@michaelchina>
To: <www-lib@w3.org>
Hello everyone,
  I am newbie of libwww. My task is to develop a module for my application which can get data from web server(I put the data into HTML&XML page). So I should parse HTML&XML page. I have seen the ready to go example for libwww. And I found showtags.c which fit my request well. But I want to use it as a module of my project. It should fetch multiple request. Such like:
initwww()
fetch()
fetch()
.......
fetch()
closewww()

Here is my module. It works in most time. But as the time goes by, It will caught a SIGSEGV signal. Seems like I have make some mistake in memory. Can anybody help me?





#include <stdlib.h>

#include "WWWLib.h"
#include "WWWInit.h"
#include "WWWHTML.h"
#include "WWWXML.h"
#include "http.h"

PRIVATE void beginElement (HText * 		text,
			   int			element_number,
			   const BOOL *		present,
			   const char **	value)
{
    SGML_dtd * dtd = HTML_dtd();
    HTTag * tag = SGML_findTag(dtd, element_number);
    if (tag)
    {
	char * tagname = HTTag_name(tag);
	if (!strcmp(tagname, "A"))
	{
	  int maxcnt = HTTag_attributes(tag);
	  int cnt;
	  for (cnt=0; cnt<maxcnt; cnt++)
	  {
	    if (present[cnt])
	    {
	      char * attrname = HTTag_attributeName(tag, cnt);
	      if (!strcmp(attrname, "HREF"))
	      {
		  if (!strncmp(value[cnt], "RoomId", 6) && (strlen(value[cnt]) > 7))
		  {
		    strncpy(g_strID, value[cnt]+7, 9);
		    g_strID[9] = '\0';
		  }
		  if (!strncmp(value[cnt], "RoomName", 6) && (strlen(value[cnt]) > 9))
		  {
		    strncpy(g_strName, value[cnt]+9, 9);
		    g_strName[9] = '\0';
		  }
	      }
	    }
	  }
	}
	HT_FREE(tagname);
    }
    HT_FREE(tag);
    HT_FREE(dtd);
}


PRIVATE void XML_startElement (void * userData,
	   	    	       const XML_Char *	name, const XML_Char ** atts)
{
  if (!strcmp(name, "row"))
  {
    int i = 0;
    songdata *tmp = NULL;
    tmp = (songdata *)g_malloc(sizeof(songdata));
    
    while(atts[i])
    {
      if (!strcmp(atts[i], "soundid")||!strcmp(atts[i], "songid")
	  ||!strcmp(atts[i], "SongID")||!strcmp(atts[i], "SoundID"))
      {
	strcpy(tmp->songid, atts[i+1]);
      }
      if (!strcmp(atts[i], "title")||!strcmp(atts[i], "Title"))
      {
	strcpy(tmp->songtitle, atts[i+1]);
      }
      if (!strcmp(atts[i], "artistname")||!strcmp(atts[i], "ArtistName"))
      {
	strcpy(tmp->singername, atts[i+1]);
      }
      if (!strcmp(atts[i], "artistid"))
      {
	strcpy(tmp->singerid, atts[i+1]);
      }
      if (!strcmp(atts[i], "played")||!strcmp(atts[i], "Played"))
      {
	tmp->state = atoi(atts[i+1]);
      }
      i++;
    }
    tmp->selected = 0;
    head = g_list_append (head, tmp);
    
  }
	    
}

PRIVATE void XML_endElement (void * userData,
			     const XML_Char * name)
{
    //HTPrint("End......... %s\n", name ? name : "<null>");
}


PRIVATE int printer (const char * fmt, va_list pArgs)
{
    return (vfprintf(stdout, fmt, pArgs));
}


PRIVATE int tracer (const char * fmt, va_list pArgs)
{
    return (vfprintf(stderr, fmt, pArgs));
}

PRIVATE int terminate_handler (HTRequest * request, HTResponse * response,
			       void * param, int status) 
{

    HTEventList_stopLoop ();
    HTRequest_delete(request);
    
    return 0;
}

PRIVATE void HTXML_setHandlers (XML_Parser me)
{
    XML_SetElementHandler(me, XML_startElement, XML_endElement);
}

PRIVATE void HTXML_newInstance (HTStream *		me,
				HTRequest *		request,
				HTFormat 		target_format,
				HTStream *		target_stream,
				XML_Parser              xmlparser,
				void * 			context)
{
    if (me && xmlparser) HTXML_setHandlers(xmlparser);
}

void
initwww()
{
  HTProfile_newHTMLNoCacheClient ("BZKTV-LIBWWW", "1.0");
  HTPrint_setCallback(printer);
  HTTrace_setCallback(tracer);
  HTNet_addAfter(terminate_handler, NULL, NULL, HT_ALL, HT_FILTER_LAST);
  HTXMLCallback_registerNew (HTXML_newInstance, NULL);
  HText_registerElementCallback(beginElement, NULL);
  
//  HTHost_setEventTimeout(5000);
}

void
closewww()
{
  HTProfile_delete();
  exit(0);
}

void
fetch (const char * url)
{
    
    char * uri = NULL;
    
    uri = HTParse(url, NULL, PARSE_ALL);

    if (uri) {
	HTRequest * request = NULL;
	HTAnchor * anchor = NULL;
	BOOL status = NO;

	request = HTRequest_new();
	
//	HTRequest_setPreemptive(request, YES);
	
	anchor = HTAnchor_findAddress(uri);

	status = HTLoadAnchor(anchor, request);

	if (status == YES) HTEventList_loop(request);
    }
    HT_FREE(uri);
    return;
}
Received on Monday, 17 February 2003 01:22:37 GMT

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