openwrt通过libcurl上传图片，服务器端通过PHP接收文件

一、客户端文件上传

　　libcurl上传文件有两种方式：

　　1、直接上传文件，类似form表单<input type=”file” />，<form enctype=”multipart/form-data”…；

　　2、上传二进制流；

设定自定义头，都是使用一样的方法

struct curl_slist *headers=NULL;
headers = curl_slist_append(headers, "Content-Type: text/xml");
headers = curl_slist_append(headers, "Accept: text/html, */*;q=0.01");
//...

//set headers
curl_easy_setopt(easyhandle, CURLOPT_HTTPHEADER, headers);

//last free the header list
curl_slist_free_all(headers); /* free the header list */　

附上开发中写的程序代码

 int UploadFile(char *file_name, char *dir_name, char *save_name)
 {
     char buff[];
     CURL *curl;  

     CURLM *multi_handle;
     int still_running;  

     struct curl_httppost *formpost=NULL;
     struct curl_httppost *lastptr=NULL;
     struct curl_slist *headerlist=NULL;
     static const char buf[] = "Expect:";  

     sprintf(buff, "%s%s%s%s", dir_name, "-", save_name, ".jpg");
     /* Fill in the file upload field. This makes libcurl load data from
         the given file name when curl_easy_perform() is called. */
     curl_formadd(&formpost,
                 &lastptr,
                 CURLFORM_COPYNAME, "file",
                 CURLFORM_FILE, file_name,
                 CURLFORM_CONTENTTYPE, "Image/jpeg",
                 CURLFORM_FILENAME, buff,
                 CURLFORM_END);  

     /* Fill in the filename field */
     curl_formadd(&formpost,
                 &lastptr,
                 CURLFORM_COPYNAME, "filename",
                 CURLFORM_COPYCONTENTS, save_name,
                 CURLFORM_END);  

     /* Fill in the submit field too, even if this is rarely needed */
     curl_formadd(&formpost,
                 &lastptr,
                 CURLFORM_COPYNAME, "directory",
                 CURLFORM_COPYCONTENTS, dir_name,
                 CURLFORM_END);  

     curl = curl_easy_init();
     multi_handle = curl_multi_init();  

     /* initalize custom header list (stating that Expect: 100-continue is not
      wanted */
     headerlist = curl_slist_append(headerlist, buf);
     if(curl && multi_handle) {  

         /* what URL that receives this POST */
         curl_easy_setopt(curl, CURLOPT_URL, "https://app.sopings.com/lock/control/_UploadFile.php");
         curl_easy_setopt(curl, CURLOPT_VERBOSE, 1L);  

         curl_easy_setopt(curl, CURLOPT_HTTPHEADER, headerlist);
         curl_easy_setopt(curl, CURLOPT_HTTPPOST, formpost);  

         if () {
             curl_easy_setopt(curl, CURLOPT_SSL_VERIFYPEER, );
             curl_easy_setopt(curl, CURLOPT_SSL_VERIFYHOST, );
         }            

         curl_multi_add_handle(multi_handle, curl);  

         curl_multi_perform(multi_handle, &still_running);  

         do {
             struct timeval timeout;
             int rc; /* select() return code */  

             fd_set fdread;
             fd_set fdwrite;
             fd_set fdexcep;
             int maxfd = -;  

             long curl_timeo = -;  

             FD_ZERO(&fdread);
             FD_ZERO(&fdwrite);
             FD_ZERO(&fdexcep);  

             /* set a suitable timeout to play around with */
             timeout.tv_sec = ;
             timeout.tv_usec = ;  

             curl_multi_timeout(multi_handle, &curl_timeo);
             if(curl_timeo >= ) {
                 timeout.tv_sec = curl_timeo / ;
                 if(timeout.tv_sec > )
                     timeout.tv_sec = ;
                 else
                 timeout.tv_usec = (curl_timeo % ) * ;
             }  

             /* get file descriptors from the transfers */
             curl_multi_fdset(multi_handle, &fdread, &fdwrite, &fdexcep, &maxfd);  

             /* In a real-world program you OF COURSE check the return code of the
              function calls.  On success, the value of maxfd is guaranteed to be
              greater or equal than -1.  We call select(maxfd + 1, ...), specially in
              case of (maxfd == -1), we call select(0, ...), which is basically equal
              to sleep. */  

             rc = select(maxfd+, &fdread, &fdwrite, &fdexcep, &timeout);  

             switch(rc) {
                 case -:
                     /* select error */
                     break;
                 case :
                 default:
                     /* timeout or readable/writable sockets */
                     printf("perform!\n");
                     curl_multi_perform(multi_handle, &still_running);
                     printf("running: %d!\n", still_running);
                     break;
             }
         } while(still_running);  

         curl_multi_cleanup(multi_handle);  

         /* always cleanup */
         curl_easy_cleanup(curl);  

         /* then cleanup the formpost chain */
         curl_formfree(formpost);  

         /* free slist */
         curl_slist_free_all (headerlist);
     }
     return ;
 }

服务器端的接收代码（PHP）

<?php

require_once (__DIR__."/../libs/Error.php");
include_once (__DIR__."/../db/Db.php");
/**
 * 上传文件
 * @author 戴栋根
 * @version 1.0
 * @created 16-三月-2016
 */
if ((($_FILES["file"]["type"] == "Image/png")
|| ($_FILES["file"]["type"] == "Image/jpeg")
|| ($_FILES["file"]["type"] == "Image/pjpeg"))
&& ($_FILES["file"]["size"] < 10000000))
{
    if ($_FILES["file"]["error"] > 0)
    {
        echo Error::getRetString(10021);
    }
    else
    {
        echo "Upload: " . $_FILES["file"]["name"] . "<br />";
        echo "Type: " . $_FILES["file"]["type"] . "<br />";
        echo "Size: " . ($_FILES["file"]["size"] / 1024) . " Kb<br />";
        echo "Temp file: " . $_FILES["file"]["tmp_name"] . "<br />";

        if (!file_exists($_FILES["directory"]["type"]))
        {
            mkdir ($_FILES["directory"]["type"]);
        }

        if (file_exists($_FILES["directory"]["type"]."/" . $_FILES["filename"]["type"]))
        {
            echo $_FILES["file"]["name"] . " already exists. ";
        }
        else
        {
            move_uploaded_file($_FILES["file"]["tmp_name"],
            $_FILES["directory"]["type"]."/" . $_FILES["filename"]["type"]);
            echo "Stored in: " . $_FILES["directory"]["type"]."/" . $_FILES["filename"]["type"];
        }
    }
}
else
{
    echo Error::getRetString(10007);
}
?>

libcurl开发文档链接