抓取url的超链接程序（使用到libcurl和libxml2）
写了一个c++语言小程序，当作练习。
c++文件：
Makefile文件：
#include <iostream>
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <string>
#include <vector>
#include <curl/curl.h>
#include <libxml/HTMLparser.h>
using namespace std;
#ifdef _MSC_VER
#define COMPARE(a, b) (!stricmp((a), (b)))
#else
#define COMPARE(a, b) (!strcasecmp((a), (b)))
#endif
typedef struct LinkStringDefined
{
string url;
string anthor_text;
} LinkString;
typedef struct ContextDefined
{
ContextDefined(): addTitle(false) { }
bool addTitle;
string title;
string url;
vector<LinkString> terms;
} Context;
static char errorBuffer[CURL_ERROR_SIZE];
static string buffer;
static int writer(char *, size_t, size_t, string *);
static bool init(CURL *&, char *);
static void parseHtml(const string &, vector<LinkString> &);
static void StartElement(void *, const xmlChar *, const xmlChar **);
static void EndElement(void *, const xmlChar *);
static void Characters(void *, const xmlChar *, int);
static void CdataBlock(void *, const xmlChar *, int);
int main(int argc, char* argv[])
{
CURL *conn = NULL;
CURLcode code;
vector<LinkString> arr;
if (argc != 2)
{
fprintf(stderr, "Usage: %s <url>/n", argv[0]);
exit(EXIT_FAILURE);
}
curl_global_init(CURL_GLOBAL_DEFAULT);
if (!init(conn, argv[1]))
{
fprintf(stderr, "Connection initializion failed/n");
exit(EXIT_FAILURE);
}
code = curl_easy_perform(conn);
curl_easy_cleanup(conn);
if (code != CURLE_OK)
{
fprintf(stderr, "Failed to get '%s' [%s]/n", argv[1], errorBuffer);
exit(EXIT_FAILURE);
}
parseHtml(buffer, arr);
int arr_size = arr.size();
for(int i = 0; i < arr_size; i ++)
{
cout << arr[i].anthor_text << "/t" << arr[i].url << endl;
}
return 0;
}
static bool init(CURL *&conn, char *url)
{
CURLcode code;
conn = curl_easy_init();
if (conn == NULL)
{
fprintf(stderr, "Failed to create CURL connection/n");
exit(EXIT_FAILURE);
}
code = curl_easy_setopt(conn, CURLOPT_ERRORBUFFER, errorBuffer);
if (code != CURLE_OK)
{
fprintf(stderr, "Failed to set error buffer [%d]/n", code);
return false;
}
code = curl_easy_setopt(conn, CURLOPT_URL, url);
if (code != CURLE_OK)
{
fprintf(stderr, "Failed to set URL [%s]/n", errorBuffer);
return false;
}
code = curl_easy_setopt(conn, CURLOPT_FOLLOWLOCATION, 1);
if (code != CURLE_OK)
{
fprintf(stderr, "Failed to set redirect option [%s]/n", errorBuffer);
return false;
}
code = curl_easy_setopt(conn, CURLOPT_WRITEFUNCTION, writer);
if (code != CURLE_OK)
{
fprintf(stderr, "Failed to set writer [%s]/n", errorBuffer);
return false;
}
code = curl_easy_setopt(conn, CURLOPT_WRITEDATA, &buffer);
if (code != CURLE_OK)
{
fprintf(stderr, "Failed to set write data [%s]/n", errorBuffer);
return false;
}
return true;
}
static int writer(char *data, size_t size, size_t nmemb, string *writerData)
{
unsigned long long sizes = size * nmemb;
if (writerData == NULL) return 0;
writerData->append(data, sizes);
return sizes;
}
static htmlSAXHandler saxHandler =
{
NULL,
NULL,
NULL,
NULL,
NULL,
NULL,
NULL,
NULL,
NULL,
NULL,
NULL,
NULL,
NULL,
NULL,
StartElement,
EndElement,
NULL,
Characters,
NULL,
NULL,
NULL,
NULL,
NULL,
NULL,
NULL,
CdataBlock,
NULL
};
static void parseHtml(const string &html, vector<LinkString> &arr)
{
htmlParserCtxtPtr ctxt;
Context context;
ctxt = htmlCreatePushParserCtxt(&saxHandler, &context, "", 0, "", XML_CHAR_ENCODING_NONE);
htmlParseChunk(ctxt, html.c_str(), html.size(), 0);
htmlParseChunk(ctxt, "", 0, 1);
htmlFreeParserCtxt(ctxt);
arr = context.terms;
}
static void StartElement(void *voidContext, const xmlChar *name, const xmlChar **attributes)
{
// int sz_att = sizeof(**attributes) / sizeof(xmlChar);
Context *context = (Context *)voidContext;
if (COMPARE((char *)name, "a"))
{
context->url = (char *)attributes[1];
context->title = "";
context->addTitle = true;
}
}
static void EndElement(void *voidContext, const xmlChar *name)
{
Context *context = (Context *)voidContext;
if (COMPARE((char *)name, "a"))
{
context->url = "";
context->addTitle = false;
}
}
static void handleCharacters(Context *context, const xmlChar *chars, int length)
{
LinkString linkString;
if (context->addTitle)
{
context->title.append((char *)chars, length);
linkString.anthor_text = context->title;
linkString.url = context->url;
context->terms.push_back(linkString);
}
}
static void Characters(void *voidContext, const xmlChar *chars, int length)
{
Context *context = (Context *)voidContext;
handleCharacters(context, chars, length);
}
static void CdataBlock(void *voidContext, const xmlChar *chars, int length)
{
Context *context = (Context *)voidContext;
handleCharacters(context, chars, length);
}
Makefile文件：
CXX = g++
WARNING = -Wall
GDBDEBUG = -g
LIBS = -L.
DEFAULT_INCLUDE = -I. -I/usr/include
ADDED_INCLUDE= -I /usr/include/libxml2
OPTIMIZE = -O2
allprog = get_url_info
object1 = get_url_info.o
complied = $(CXX) $(GDBDEBUG) $(WARNING) $(OPTIMIZE) $(DEFAULT_INCLUDE) $(ADDED_INCLUDE) -c $*.cpp
all : ${allprog}
.cpp.o :
$(complied)
get_url_info : $(object1)
$(CXX) $(GDBDEBUG) $(WARNING) -lcurl -lxml2 $(OPTIMIZE) -o get_url_info $(object1)
.PHONY : cleanall clean cleanobj
cleanall :
-rm *.o ${allprog}
clean :
-rm $(object1) get_url_info
cleanobj :
-rm *.o