在简易界面上使用环境 libcurl 时,首先必须调用:
curl_easy_init()
,它初始化了简单的句柄,
curl_global_init()
,大多数情况下标志选项必须是CURL_GLOBAL_ALL
这两个函数中的每一个在开始时只被调用一次,并且需要它们相反的清理:
curl_easy_cleanup()
当你完成你声明的句柄时,
curl_global_cleanup()
当你用完 libcurl,
为了获得更好的结果,请尽可能多地检查错误。Libcurl 为此提供了curl_easy_strerror()
功能。它返回一个描述 CURLcode 错误的字符串。此外,如果一切正常,某些函数会返回值 CURL_OK 或特定整数。
例如,这是使用 CURLOPT_URL 选项的正确方法:
#include <curl.h>
int main(void)
{
/* declaration of an object CURL */
CURL *handle;
/* result of the whole process */
CURLcode result;
/* the first functions */
/* set up the program environment that libcurl needs */
curl_global_init(CURL_GLOBAL_ALL);
/* curl_easy_init() returns a CURL easy handle that you're gonna reuse in other easy functions*/
handle = curl_easy_init();
/* if everything's all right with the easy handle... */
if(handle)
{
/* ...you can list the easy functions */
/* here we just gonna try to get the source code of http://example.com */
curl_easy_setopt(handle, CURLOPT_URL, "http://example.com");
/* but in that case we also tell libcurl to follow redirection */
curl_easy_setopt(handle, CURLOPT_FOLLOWLOCATION, 1L);
/* perform, then store the expected code in 'result'*/
result = curl_easy_perform(handle);
/* Check for errors */
if(result != CURLE_OK)
{
/* if errors have occured, tell us wath's wrong with 'result'*/
fprintf(stderr, "curl_easy_perform() failed: %s\n", curl_easy_strerror(result));
return 1;
}
}
/* if something's gone wrong with curl at the beginning, we'll appriciate that piece of code */
else
{
fprintf(stderr, "Curl init failed!\n");
return 1;
}
/* cleanup since you've used curl_easy_init */
curl_easy_cleanup(handle);
/* this function releases resources acquired by curl_global_init() */
curl_global_cleanup();
/* make the programme stopping for avoiding the console closing befor you can see anything */
system("PAUSE");
return 0;
}
如果您想将该句柄重用于完全不同的目的,您最好使用不同的 CURL 简单句柄。您的代码仍然可以正常工作,但我会使用不同的句柄,因为它显然是两个单独的操作。
但是,有时您需要使用相同的句柄,如果您不想自动重置它,请使用适当的功能:
void curl_easy_reset(CURL *handle);
请注意,它不会更改实时连接、会话 ID 缓存、DNS 缓存、cookie 和句柄中的共享。
我还没有尝试过,但是使用您的代码应该会给我们类似的东西:
#include <curl.h>
int main(void)
{
CURL *handle;
CURLcode result;
int error = 0;
int error2 = 0;
curl_global_init(CURL_GLOBAL_ALL);
handle = curl_easy_init();
if(handle)
{
curl_easy_setopt(handle, CURLOPT_USERAGENT, "Mozilla/5.0 (Windows; U; Windows NT 6.1; fr; rv:1.9.2) Gecko/20100115 Firefox/3.6");
curl_easy_setopt(handle, CURLOPT_URL, "http://www.google.com");
result = curl_easy_perform(handle);
if(result != CURLE_OK)
{
fprintf(stderr, "curl_easy_perform() failed: %s\n", curl_easy_strerror(result));
error++;
}
Sleep(5000); // make a pause if you working on console application
curl_easy_reset(handle);
curl_easy_setopt(handle, CURLOPT_USERAGENT, "Mozilla/5.0 (Windows; U; Windows NT 6.1; fr; rv:1.9.2) Gecko/20100115 Firefox/3.6"); // have to write it again
curl_easy_setopt(handle, CURLOPT_URL, "http://www.bbc.com");
result = curl_easy_perform(handle);
if(result != CURLE_OK)
{
fprintf(stderr, "curl_easy_perform() failed: %s\n", curl_easy_strerror(result));
error2++;
}
if(error == 1 || error2 == 1)
{
return 1;
}
}
else
{
fprintf(stderr, "Curl init failed!\n");
return 1;
}
curl_easy_cleanup(handle);
curl_global_cleanup();
system("PAUSE");
return 0;
}
如果您对 有任何问题,请Sleep
尝试将其替换为sleep
或_sleep
或将 5000 替换为 5。