#include <stdio.h>#include <string.h> #include <curl/curl.h> int main(int argc, char *argv[]){  CURL *curl;  CURLcode res;   struct curl_httppost *formpost=NULL;  struct curl_httppost *lastptr=NULL;  struct curl_slist *headerlist=NULL;  static const char buf[] = "Expect:";   curl_global_init(CURL_GLOBAL_ALL);   /* Fill in the file upload field */   curl_formadd(&formpost,               &lastptr,               CURLFORM_COPYNAME, "message",               CURLFORM_COPYCONTENTS, "hello",               CURLFORM_END);   /* Fill in the filename field */   curl_formadd(&formpost,               &lastptr,               CURLFORM_COPYNAME, "filename",               CURLFORM_FILE,"test.xlsx",               CURLFORM_CONTENTTYPE, "application/vnd.ms-excel",               CURLFORM_END);   curl = curl_easy_init();  /* initalize custom header list (stating that Expect: 100-continue is not     wanted */   headerlist = curl_slist_append(headerlist, buf);  if(curl) {    /* what URL that receives this POST */     curl_easy_setopt(curl, CURLOPT_URL, "http://192.168.1.107/protocol/upload_questions/");    if ( (argc == 2) && (!strcmp(argv[1], "noexpectheader")) )      /* only disable 100-continue header if explicitly requested */       curl_easy_setopt(curl, CURLOPT_HTTPHEADER, headerlist);    curl_easy_setopt(curl, CURLOPT_HTTPPOST, formpost);     /* 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);     /* then cleanup the formpost chain */     curl_formfree(formpost);    /* free slist */     curl_slist_free_all (headerlist);  }  return 0;}