求解libcurl取返回网页.以及代理设置方法

[Y.A.K.E]

定义一个函数

string getweb(url:string,proxy:string)
{
//使得最后返回的是网页的HTML代码.错误则返回空.
curl = curl_easy_init(); //初始化一个CURL类型的指针
if(curl!=NULL)
{

curl_easy_setopt(curl, CURLOPT_URL, url);
res = curl_easy_perform(curl);
curl_easy_cleanup(curl);
//....
}

不过我这样只能打印在屏幕上..不能作为返回.
网上翻了很多.只找到保存到文件的方法,而且必须要回调函数...

有没有直接可以返回的?
我记得以前PHP可以用缓冲区..


另外求代理设置方法

[qq120848369]

注册writefunction.

[Y.A.K.E]

引用 1 楼 qq120848369 的回复:

注册writefunction.

这个必须使用回调函数吧...

[旋转的棍子]

引用 2 楼 xunni1000 的回复:

[quote=引用 1 楼 qq120848369 的回复:] 注册writefunction.

这个必须使用回调函数吧...[/quote]你回调的时候，不写文件，而是把数据写进你的缓存区就行了

[Y.A.K.E]

引用 3 楼 lovecuicui13 的回复:

[quote=引用 2 楼 xunni1000 的回复:] [quote=引用 1 楼 qq120848369 的回复:] 注册writefunction.

这个必须使用回调函数吧...[/quote]你回调的时候，不写文件，而是把数据写进你的缓存区就行了[/quote] 缓存区好高级的样子..不会啊,大侠

[Y.A.K.E]

引用 6 楼 lovecuicui13 的回复:

[quote=引用 5 楼 lovecuicui13 的回复:]

#define MAX_BUF 	 65536
char wr_buf[MAX_BUF+1];
void test() 
{
    .....
    if (curl) {
		 curl_easy_setopt(curl, CURLOPT_COOKIEFILE, "d:/cookie.txt"); // 指定cookie文件
		 curl_easy_setopt(curl, CURLOPT_COOKIEJAR, "d:/cookie.txt");
		 curl_easy_setopt(curl, CURLOPT_HTTPHEADER, headers );
		 curl_easy_setopt(curl, CURLOPT_URL, sign_url);   // 指定url
		 curl_easy_setopt(curl, CURLOPT_READDATA, (void *)&wr_error);
		 curl_easy_setopt(curl, CURLOPT_WRITEFUNCTION, write_data );//调用写回调
		
		 /* Allow curl to perform the action */
		 res = curl_easy_perform(curl);
		 printf( "ret = %d (write_error = %d)\n", res, wr_error );

		  /* Emit the page if curl indicates that no errors occurred */
		 if ( res == 0 ) 
			printf( "%s\n", wr_buf );
		 curl_slist_free_all(headers);
		 curl_easy_cleanup(curl);
	}
    .....
}
/*
 * Write data callback function (called within the context of
 * curl_easy_perform.
 */
size_t write_data( void *buffer, size_t size, size_t nmemb, void *userp ) {
	int segsize = size * nmemb;

	  /* Check to see if this data exceeds the size of our buffer. If so,
	   * set the user-defined context value and return 0 to indicate a
	   * problem to curl.
	   */
	  if ( wr_index + segsize > MAX_BUF ) {
	    *(int *)userp = 1;
	    return 0;
	  }

	  /* Copy the data from the curl buffer into our buffer */
	  memcpy( (void *)&wr_buf[wr_index], buffer, (size_t)segsize );

	  /* Update the write index */
	  wr_index += segsize;

	  /* Null terminate the buffer */
	  wr_buf[wr_index] = 0;

	  /* Return the number of bytes received, indicating to curl that all is okay */
	  return segsize;
}

前面还有个记录已经使用的位置的变量 int wr_index=0;[/quote] 请问如果希望test()返回呢.网页内容呢

[旋转的棍子]

#define MAX_BUF 	 65536
char wr_buf[MAX_BUF+1];
void test() 
{
    .....
    if (curl) {
		 curl_easy_setopt(curl, CURLOPT_COOKIEFILE, "d:/cookie.txt"); // 指定cookie文件
		 curl_easy_setopt(curl, CURLOPT_COOKIEJAR, "d:/cookie.txt");
		 curl_easy_setopt(curl, CURLOPT_HTTPHEADER, headers );
		 curl_easy_setopt(curl, CURLOPT_URL, sign_url);   // 指定url
		 curl_easy_setopt(curl, CURLOPT_READDATA, (void *)&wr_error);
		 curl_easy_setopt(curl, CURLOPT_WRITEFUNCTION, write_data );//调用写回调
		
		 /* Allow curl to perform the action */
		 res = curl_easy_perform(curl);
		 printf( "ret = %d (write_error = %d)\n", res, wr_error );

		  /* Emit the page if curl indicates that no errors occurred */
		 if ( res == 0 ) 
			printf( "%s\n", wr_buf );
		 curl_slist_free_all(headers);
		 curl_easy_cleanup(curl);
	}
    .....
}
/*
 * Write data callback function (called within the context of
 * curl_easy_perform.
 */
size_t write_data( void *buffer, size_t size, size_t nmemb, void *userp ) {
	int segsize = size * nmemb;

	  /* Check to see if this data exceeds the size of our buffer. If so,
	   * set the user-defined context value and return 0 to indicate a
	   * problem to curl.
	   */
	  if ( wr_index + segsize > MAX_BUF ) {
	    *(int *)userp = 1;
	    return 0;
	  }

	  /* Copy the data from the curl buffer into our buffer */
	  memcpy( (void *)&wr_buf[wr_index], buffer, (size_t)segsize );

	  /* Update the write index */
	  wr_index += segsize;

	  /* Null terminate the buffer */
	  wr_buf[wr_index] = 0;

	  /* Return the number of bytes received, indicating to curl that all is okay */
	  return segsize;
}

[旋转的棍子]

引用 5 楼 lovecuicui13 的回复:

#define MAX_BUF 	 65536
char wr_buf[MAX_BUF+1];
void test() 
{
    .....
    if (curl) {
		 curl_easy_setopt(curl, CURLOPT_COOKIEFILE, "d:/cookie.txt"); // 指定cookie文件
		 curl_easy_setopt(curl, CURLOPT_COOKIEJAR, "d:/cookie.txt");
		 curl_easy_setopt(curl, CURLOPT_HTTPHEADER, headers );
		 curl_easy_setopt(curl, CURLOPT_URL, sign_url);   // 指定url
		 curl_easy_setopt(curl, CURLOPT_READDATA, (void *)&wr_error);
		 curl_easy_setopt(curl, CURLOPT_WRITEFUNCTION, write_data );//调用写回调
		
		 /* Allow curl to perform the action */
		 res = curl_easy_perform(curl);
		 printf( "ret = %d (write_error = %d)\n", res, wr_error );

		  /* Emit the page if curl indicates that no errors occurred */
		 if ( res == 0 ) 
			printf( "%s\n", wr_buf );
		 curl_slist_free_all(headers);
		 curl_easy_cleanup(curl);
	}
    .....
}
/*
 * Write data callback function (called within the context of
 * curl_easy_perform.
 */
size_t write_data( void *buffer, size_t size, size_t nmemb, void *userp ) {
	int segsize = size * nmemb;

	  /* Check to see if this data exceeds the size of our buffer. If so,
	   * set the user-defined context value and return 0 to indicate a
	   * problem to curl.
	   */
	  if ( wr_index + segsize > MAX_BUF ) {
	    *(int *)userp = 1;
	    return 0;
	  }

	  /* Copy the data from the curl buffer into our buffer */
	  memcpy( (void *)&wr_buf[wr_index], buffer, (size_t)segsize );

	  /* Update the write index */
	  wr_index += segsize;

	  /* Null terminate the buffer */
	  wr_buf[wr_index] = 0;

	  /* Return the number of bytes received, indicating to curl that all is okay */
	  return segsize;
}

前面还有个记录已经使用的位置的变量 int wr_index=0;

[旋转的棍子]

数据已经写到 char wr_buf[MAX_BUF+1]; 里面了啊，你直接用就是了