libcurl

http://www.cppblog.com/qiujian5628/archive/2008/06/28/54873.htmllibcurlhttp://baike.baidu.com/view/1806203.htm使用心得 Libcurl为一个免费开源的，客户端url传输库，支持FTP，FTPS，TFTP，HTTP，HTTPS，GOPHER，TELNET，DICT，FILE和LDAP，跨平台，支持Windows，Unix，Linux等，线程安全，支持Ipv6。并且易于使用。http://curl.haxx.se/libcurl/从http://curl.haxx.se/libcurl/ 下载一个稳定的版本，注意选择OS。在使用之前请大家多阅读libcurl的文档：因为如果要实际运用到项目中，最好对libcurl有具体的了解，具体在http://curl.haxx.se/libcurl/c/curl_easy_setopt() curl_easy_perform() curl_easy_getinfo() 这三个函数的使用上，需要多去钻研，多看Samples，你才能灵活使用libcurl。感谢这篇文章:http://blog.163.com/xu_chao2000/blog/static/27770610200801303252802/给了我许多启发，再次感谢！给出我的一个简单的代码例子：说明:1.关键在curl_easy_setopt函数设置option,可以设置ftp,http,get,post等许多选项，请根据具体使用情况设置。2.对取回来的数据需要进行判断，比如http下载文件，如果文件不存在，需要进行处理。因为writer是可以将buf填充404 not found等网页内容的，不能将这个内容当成文件内容，所以需要判断http web返回来的code，进行判断。3.我有个问题，就是想得到服务器上filename的具体名称，verbose调试已经返回了，但是我在getinfo的时候，试过好多选项，但未找到这个存放真实服务器文件名的选项，如果有知道的麻烦告诉我，谢谢了！#include "curl/curl.h"#pragma comment(lib, "libcurl.lib")long writer(void *data, int size, int nmemb, string &content);bool CurlInit(CURL *&curl, const char* url,string &content);bool GetURLDataBycurl(const char* URL, string &content);void main(){ char *url ="http://www.baidu.com/img/baidu.gif"; string content; if ( GetURLDataBycurl(url,content)) { printf("%s\n",content); } getchar();}bool CurlInit(CURL *&curl, const char* url,string &content){ CURLcode code; string error; curl = curl_easy_init(); if (curl == NULL) { printf( "Failed to create CURL connection\n"); return false; } code = curl_easy_setopt(curl, CURLOPT_ERRORBUFFER, error); if (code != CURLE_OK) { printf( "Failed to set error buffer [%d]\n", code ); return false; } curl_easy_setopt(curl, CURLOPT_VERBOSE, 1L); code = curl_easy_setopt(curl, CURLOPT_URL, url); if (code != CURLE_OK) { printf("Failed to set URL [%s]\n", error); return false; } code = curl_easy_setopt(curl, CURLOPT_FOLLOWLOCATION, 1); if (code != CURLE_OK) { printf( "Failed to set redirect option [%s]\n", error ); return false; } code = curl_easy_setopt(curl, CURLOPT_WRITEFUNCTION, writer); if (code != CURLE_OK) { printf( "Failed to set writer [%s]\n", error); return false; } code = curl_easy_setopt(curl, CURLOPT_WRITEDATA, &content); if (code != CURLE_OK) { printf( "Failed to set write data [%s]\n", error ); return false; } return true;}long writer(void *data, int size, int nmemb, string &content){ long sizes = size * nmemb; string temp(data,sizes); content += temp; return sizes;}bool GetURLDataBycurl(const char* URL, string &content){ CURL *curl = NULL; CURLcode code; string error; code = curl_global_init(CURL_GLOBAL_DEFAULT); if (code != CURLE_OK) { printf( "Failed to global init default [%d]\n", code ); return false; } if ( !CurlInit(curl,URL,content) ) { printf( "Failed to global init default [%d]\n" ); return PM_FALSE; } code = curl_easy_perform(curl); if (code != CURLE_OK) { printf( "Failed to get '%s' [%s]\n", URL, error); return false; } long retcode = 0; code = curl_easy_getinfo(curl, CURLINFO_RESPONSE_CODE , &retcode); if ( (code == CURLE_OK) && retcode == 200 ) { double length = 0; code = curl_easy_getinfo(curl, CURLINFO_CONTENT_LENGTH_DOWNLOAD , &length); printf("%d",retcode); FILE * file = fopen("1.gif","wb"); fseek(file,0,SEEK_SET); fwrite(content.c_str(),1,length,file); fclose(file); //struct curl_slist *list; //code = curl_easy_getinfo(curl,CURLINFO_COOKIELIST,&list); //curl_slist_free_all (list); return true; } else { // debug1( "%s \n ",getStatusCode(retcode)); return false; } curl_easy_cleanup(curl); return false;}