libcurl windows编译，运行配置

1. 编译
   官方下载源码，找到winbuild目录。打开vs2013开发人员命令提示工具，编译debug版本：E:\cpp11\curl-7.51.0\winbuild>nmake /f Makefile.vc mode=static VC=12 DEBUG=yes
   编译relase版本去掉DEBUG=yes就可以了；
   builds目录下找到生成的include和lib目录；
2. 使用
   附加头文件目录；
   链接器加入lib库；
   关键，关键，关键，C/C++预处理器中加入：BUILDING_LIBCURL
3. 上传文件例子

// ConsoleApplication7.cpp : 定义控制台应用程序的入口点。//#include "stdafx.h"#include <stdio.h>#include <curl/curl.h>#include <sys/stat.h>#include <fcntl.h>int main(void){    CURL *curl;    CURLcode res;    struct stat file_info;    double speed_upload, total_time;    FILE *fd;    fopen_s(&fd, "hello", "rb");    //fd = fopen("debugit", "rb"); /* open file to upload */    if (!fd) {        return 1; /* can't continue */    }    /* to get the file size */    if (fstat(_fileno(fd), &file_info) != 0) {        return 1; /* can't continue */    }    curl = curl_easy_init();    if (curl) {        /* upload to this place */        curl_easy_setopt(curl, CURLOPT_URL,            "localhost:3000/hello");        /* tell it to "upload" to the URL */        curl_easy_setopt(curl, CURLOPT_UPLOAD, 1L);        /* set where to read from (on Windows you need to use READFUNCTION too) */        curl_easy_setopt(curl, CURLOPT_READDATA, fd);        /* and give the size of the upload (optional) */        curl_easy_setopt(curl, CURLOPT_INFILESIZE_LARGE,            (curl_off_t)file_info.st_size);        /* enable verbose for easier tracing */        curl_easy_setopt(curl, CURLOPT_VERBOSE, 1L);        res = curl_easy_perform(curl);        /* Check for errors */        if (res != CURLE_OK) {            fprintf(stderr, "curl_easy_perform() failed: %s\n",                curl_easy_strerror(res));        }        else {            /* now extract transfer info */            curl_easy_getinfo(curl, CURLINFO_SPEED_UPLOAD, &speed_upload);            curl_easy_getinfo(curl, CURLINFO_TOTAL_TIME, &total_time);            fprintf(stderr, "Speed: %.3f bytes/sec during %.3f seconds\n",                speed_upload, total_time);        }        /* always cleanup */        curl_easy_cleanup(curl);    }    system("pause");    return 0;}

上传文件：

#include "httpcurl.h"#include <stdio.h>#include <curl/curl.h>#include <sys/stat.h>#include <fcntl.h>static const int OPEN_FILE_ERROR = 100;static const int FILE_SIZE_ZERO = 101;namespace httpcurl {    struct WriteThis {        FILE *fd;        long size;    };    static size_t read_callback(void *ptr, size_t size, size_t nmemb, void *userp)    {        struct WriteThis *pooh = (struct WriteThis *)userp;        if (size*nmemb < 1) {            return 0;        }        size_t readSize = fread(ptr, size, nmemb, pooh->fd);        pooh->size -= readSize;        return readSize;    }    int UploadFileSync(const std::string &url, const std::string &filePath)    {        CURL *curl;        CURLcode res;        struct stat file_info;        struct WriteThis pooh;        pooh.fd = fopen(filePath.c_str(), "rb");        if (!pooh.fd) {            return OPEN_FILE_ERROR;        }        fstat(_fileno(pooh.fd), &file_info);        pooh.size = file_info.st_size;        if (pooh.size == 0) {            return FILE_SIZE_ZERO;        }        /* In windows, this will init the winsock stuff */        res = curl_global_init(CURL_GLOBAL_DEFAULT);        /* Check for errors */        if (res != CURLE_OK) {            return res;        }        /* get a curl handle */        curl = curl_easy_init();        if (curl) {            /* First set the URL that is about to receive our POST. */            curl_easy_setopt(curl, CURLOPT_URL, url.c_str());            /* Now specify we want to POST data */            curl_easy_setopt(curl, CURLOPT_POST, 1L);            /* we want to use our own read function */            curl_easy_setopt(curl, CURLOPT_READFUNCTION, read_callback);            /* pointer to pass to our read function */            curl_easy_setopt(curl, CURLOPT_READDATA, &pooh);            /* get verbose debug output please */            curl_easy_setopt(curl, CURLOPT_VERBOSE, 1L);            /*            If you use POST to a HTTP 1.1 server, you can send data without knowing            the size before starting the POST if you use chunked encoding. You            enable this by adding a header like "Transfer-Encoding: chunked" with            CURLOPT_HTTPHEADER. With HTTP 1.0 or without chunked transfer, you must            specify the size in the request.            */#ifdef USE_CHUNKED            {                struct curl_slist *chunk = NULL;                chunk = curl_slist_append(chunk, "Transfer-Encoding: chunked");                res = curl_easy_setopt(curl, CURLOPT_HTTPHEADER, chunk);                /* use curl_slist_free_all() after the *perform() call to free this                list again */            }#else            /* Set the expected POST size. If you want to POST large amounts of data,            consider CURLOPT_POSTFIELDSIZE_LARGE */            curl_easy_setopt(curl, CURLOPT_POSTFIELDSIZE, file_info.st_size);#endif#ifdef DISABLE_EXPECT            /*            Using POST with HTTP 1.1 implies the use of a "Expect: 100-continue"            header.  You can disable this header with CURLOPT_HTTPHEADER as usual.            NOTE: if you want chunked transfer too, you need to combine these two            since you can only set one list of headers with CURLOPT_HTTPHEADER. */            /* A less good option would be to enforce HTTP 1.0, but that might also            have other implications. */            {                struct curl_slist *chunk = NULL;                chunk = curl_slist_append(chunk, "Expect:");                res = curl_easy_setopt(curl, CURLOPT_HTTPHEADER, chunk);                /* use curl_slist_free_all() after the *perform() call to free this                list again */            }#endif            /* Perform the request, res will get the return code */            res = curl_easy_perform(curl);            /* Check for errors */            if (res != CURLE_OK)                fprintf(stderr, "curl_easy_perform() failed: %s\n",                curl_easy_strerror(res));            /* always cleanup */            curl_easy_cleanup(curl);        }        curl_global_cleanup();        fclose(pooh.fd);        return res;    }    std::string GetErrorStr(int err)    {        if (err > CURLE_OK && err < CURL_LAST) {            return curl_easy_strerror((CURLcode)err);        }        switch (err) {        case 0:            return "success";            break;        case OPEN_FILE_ERROR:            return "open file error";            break;        case FILE_SIZE_ZERO:            return "file size is zero";            break;        default:            return "unkown";            break;        }    }}