首先使用上一篇文章介绍的libcurl库post请求获取OJ题目HTML源码，在使用pcre库正则表达式匹配，注意pcre需要编译出lib和dll哦。

 

下面是作者写的抓取HDOJ题目信息的源代码，是不是很简单呢？

// Spider.cpp : Defines the entry point for the console application.

//

/*

C/C++抓取OJ题目信息

Author: Jungle Wei

Create Date: 2013-01-16

*/

#define PCRE_STATIC // 静态库编译选项

#include <io.h>

#include "curl\curl.h"

#include <iostream>

#include <cstdio>

#include <string>

#include <fstream>

#include <stdio.h>

#include "pcre.h"

using namespace std;

#pragma comment(lib, "pcre.lib") 

#pragma comment(lib, "curllib.lib") 

#pragma comment(lib, "openldap.lib") 

#pragma comment(lib, "ssleay32.lib") 

#define MAX_SIZE_BUF 1000000

CURL *curl;

CURLcode res;

char tmps[MAX_SIZE_BUF];

char username[1000]="username";

char password[1000]="password";

char tfilename[1000]="tmpfile.txt";

char domain[255]="acm.hdu.edu.cn";  //acm.guet.edu.cn

struct curl_slist *headerlist=NULL;

#define DEBUG_PRINT(X)   X

#define UCHAR unsigned char

#define ULONG unsigned long

#define CHAR char

#define BOOL_TRUE 0

#define BOOL_FALSE 1

#define OVECCOUNT 30    /* should be a multiple of 3 */

size_t process_data(void *buffer, size_t size, size_t nmemb, void *user_p)

{

FILE *fp = (FILE *)user_p;

size_t return_size = fwrite(buffer, size, nmemb, fp);

//cout << (char *)buffer << endl;

return return_size;

}

ULONG getInfoByTag(char *src, char *pattern, char *res)

{

    pcre  *re;    

    const char *error;    

    int  erroffset;    

    int  ovector[OVECCOUNT];    

    int  rc, i;    

   

//title

re = pcre_compile(pattern, 0, &error, &erroffset, NULL);         

    if (re == NULL) {                 //如果编译失败，返回错误信息    

        printf("PCRE compilation failed at offset %d: %s\n", erroffset, error);    

        return BOOL_FALSE;    

    }    

    rc = pcre_exec(re,NULL, src, strlen(src), 0, 0, ovector, OVECCOUNT);    

// 返回值：匹配成功返回非负数，没有匹配返回负数    

    if (rc < 0) {                     //如果没有匹配，返回错误信息    

        if (rc == PCRE_ERROR_NOMATCH) printf("Sorry, no match ...\n");    

        else printf("Matching error %d\n", rc);    

        pcre_free(re);    

        return BOOL_FALSE;    

    }

i = (rc==0)?(0):(rc-1);

// for (i = 0; i < rc; i++) //分别取出捕获分组 $0整个正则公式 $1第一个()  

{               

        char *substring_start =  src + ovector[2*i];    

        int substring_length = ovector[2*i+1] - ovector[2*i];    

        

printf("%.*s\n", substring_length, substring_start);

    }   

pcre_free(re);                     // 编译正则表达式re 释放内存   

return BOOL_TRUE;

}

int getProblemInfo_Brief(char *filename)    

{    

string res="",ts;

    FILE * fp=fopen(filename,"r");

    while (fgets(tmps, MAX_SIZE_BUF, fp))

    {

        ts +=tmps;

    }

    fclose(fp);

char  patternTime [] = "(\\d*) MS";  // 将要被编译的字符串形式的正则表达式    

char  patternMemory [] = "(\\d*) K";  // 将要被编译的字符串形式的正则表达式    

char  patternTitle [] = "<h1 style='color:#1A5CC8'>([\\s\\S]*?)</h1>";  // 将要被编译的字符串形式的正则表达式    

    

char  patternDescription [] = "Problem Description</div> <div class=panel_content>([\\s\\S]*?)</div><div class=panel_bottom>&nbsp;</div>";  // 将要被编译的字符串形式的正则表达式    

    

char  patternInput [] = "Input</div> <div class=panel_content>([\\s\\S]*?)</div><div class=panel_bottom>&nbsp;</div>";  // 将要被编译的字符串形式的正则表达式    

    

char  patternOutput [] = "Output</div> <div class=panel_content>([\\s\\S]*?)</div><div class=panel_bottom>&nbsp;</div>";  // 将要被编译的字符串形式的正则表达式    

    

char  patternSampleInput [] = "Sample Input</div><div class=panel_content><pre><div style=\"font-family:Courier New,Courier,monospace;\">([\\s\\S]*?)</div></pre></div><div class=panel_bottom>&nbsp;</div>";  // 将要被编译的字符串形式的正则表达式    

char  patternSampleOutput [] = "Sample Output</div><div class=panel_content><pre><div style=\"font-family:Courier New,Courier,monospace;\">([\\s\\S]*?)</div></pre></div><div class=panel_bottom>&nbsp;</div>";  // 将要被编译的字符串形式的正则表达式    

    

char  patternAuthor [] = "Author</div> <div class=panel_content>([\\s\\S]*?)</div><div class=panel_bottom>&nbsp;</div>";  // 将要被编译的字符串形式的正则表达式    

    

//char  patternTitle [] = "<h1 style='color:#1A5CC8'>([\\s\\S]*?)</h1>";  // 将要被编译的字符串形式的正则表达式    

    

puts("Time");

getInfoByTag((char*)ts.c_str(), patternTime, NULL);

puts("Memoty");

getInfoByTag((char*)ts.c_str(), patternMemory, NULL);

puts("Title");

getInfoByTag((char*)ts.c_str(), patternTitle, NULL);

puts("Description");

getInfoByTag((char*)ts.c_str(), patternDescription, NULL);

puts("Input");

getInfoByTag((char*)ts.c_str(), patternInput, NULL);

puts("Output");

getInfoByTag((char*)ts.c_str(), patternOutput, NULL);

puts("Sample Input");

getInfoByTag((char*)ts.c_str(), patternSampleInput, NULL);

puts("Sample Output");

getInfoByTag((char*)ts.c_str(), patternSampleOutput, NULL);

puts("Author");

getInfoByTag((char*)ts.c_str(), patternAuthor, NULL);

    return 0;    

}    

ULONG getProblemInfo(string pid)

{

CURL *curl;

    CURLcode res;

    curl = curl_easy_init();

    if ( curl ) {

FILE *fp = fopen(tfilename, "ab+");

curl_easy_setopt( curl, CURLOPT_VERBOSE, 0L );

curl_easy_setopt(curl, CURLOPT_COOKIEFILE, "hdu.cookie");

char url[255] = {0};

sprintf(url, "http://acm.hdu.edu.cn/showproblem.php?pid=%s", pid.c_str());

//cout<<url;

curl_easy_setopt( curl, CURLOPT_URL, url);

curl_easy_setopt(curl, CURLOPT_WRITEFUNCTION, &process_data);

curl_easy_setopt(curl, CURLOPT_WRITEDATA, fp);

res = curl_easy_perform( curl );

curl_easy_cleanup(curl);

fclose(fp);

}

getProblemInfo_Brief(tfilename);

return BOOL_TRUE;

}

int main(int argc, char *argv[])

{

if (access(tfilename, 0) == 0)

{

DeleteFile(tfilename);

}

    curl_global_init(CURL_GLOBAL_ALL);

if (BOOL_TRUE != getProblemInfo("1000"))

{

puts("getProblemInfo failed.");

}

    return 0;

}

运行效果：

Time

1000

Memoty

32768

Title

A + B Problem

Description

Calculate <i>A + B</i>.<br>

Input

Each line will contain two integers <i>A</i> and <i>B</i>. Process to end of file.<br>

Output

For each case, output <i>A + B</i> in one line.<br>

Sample Input

1 1

Sample Output

2

Author

HDOJ

Press any key to continue

http://acm.hdu.edu.cn/showproblem.php?pid=1000