Sending file to HTTP server (C++ Wininet) - c++

Question

I have code for uploading small .txt files on my HTTP-server:
#include <wininet.h>
#define BUF_SIZE 4096
void __fastcall TForm1::Button1Click(TObject *Sender)
{
TStringList * list = new TStringList();
AnsiString Path = "";
if(OpenDialog1->Execute()) {
Path = "filename=\""+OpenDialog1->FileName+"\"";
list->LoadFromFile(OpenDialog1->FileName);
}
char data[BUF_SIZE] = "";
static char hdrs[] = "Content-Type: multipart/form-data; boundary=---------------------------7d82751e2bc0858";
strcat(data,"-----------------------------7d82751e2bc0858");
strcat(data,"\n");
strcat(data,"Content-Disposition: form-data; name=\"files[]\"; ");
strcat(data,Path.c_str());
strcat(data,"\n");
strcat(data,"Content-Type: application/octet-stream");
strcat(data,"\n\n");
strcat(data,list->Text.c_str());
strcat(data,"\n");
strcat(data,"-----------------------------7d82751e2bc0858");
strcat(data,"\n");
strcat(data,"Content-Disposition: form-data; name=\"user\"");
strcat(data,"\r\n\r\n");
strcat(data,"username");
strcat(data,"\r\n");
strcat(data,"-----------------------------7d82751e2bc0858");
strcat(data,"\n");
HINTERNET hSession = InternetOpen("MyAgent",INTERNET_OPEN_TYPE_PRECONFIG, NULL, NULL, 0);
HINTERNET hConnect = InternetConnect(hSession, "localhost",INTERNET_DEFAULT_HTTP_PORT, NULL, NULL, INTERNET_SERVICE_HTTP, 0, 1);
HINTERNET hRequest = HttpOpenRequest(hConnect, "POST", "new_upltest.php", NULL, NULL, NULL, 0, 1);
HttpSendRequest(hRequest, hdrs, strlen(hdrs), data, strlen(data));
delete list;
}
It's working fine, but now I'm needing to upload big files (over 70-100 mb), that can be images (.jpg, .png, .bmp) and other document types (.pdf, .docx, etc).
Is it possible to solve my task with this code? I will be grateful for each advices...
P.S. My IDE is C++ Builder 6, but I think it doesn't matter.

Answer 1

This is working example for one file uploading:
void http_upload_file(PCHAR szServer, PCHAR szScript, PCHAR szParam, PCHAR szValue, PCHAR szFile)
{
PCHAR szHeaders = "Content-Type: multipart/form-data; boundary=----qwerty";
PCHAR szData = "------qwerty\r\n"
"Content-Disposition: form-data; name=\"%s\"\r\n\r\n%s\r\n"
"------qwerty\r\n"
"Content-Disposition: form-data; name=\"files[]\"; filename=\"%s\"\r\n"
"Content-Type: application/octet-stream\r\n"
"Content-Transfer-Encoding: binary\r\n\r\n";
PCHAR szDataEnd = "\r\n------qwerty--\r\n";
char szHeader[512];
HINTERNET hSession, hConnect, hRequest;
DWORD dwFileSize, dwBytesRead, dwContentLength,dwBytesWritten;
hSession = InternetOpen(NULL, INTERNET_OPEN_TYPE_DIRECT, NULL, NULL, 0);
if (hSession)
{
hConnect = InternetConnect(hSession, szServer, INTERNET_DEFAULT_HTTP_PORT, NULL, NULL, INTERNET_SERVICE_HTTP,0, 0);
if (hConnect)
{
hRequest = HttpOpenRequest(hConnect, "POST", szScript, NULL, NULL, 0, 0, 0);
if (hRequest)
{
HANDLE hFile = CreateFile(szFile, GENERIC_READ, FILE_SHARE_READ, NULL, OPEN_EXISTING, NULL, NULL);
if (hFile != INVALID_HANDLE_VALUE)
{
dwFileSize = GetFileSize(hFile, NULL);
wsprintf(szHeader, szData, szParam, szValue, szFile);
dwContentLength = lstrlen(szHeader) + dwFileSize + lstrlen(szDataEnd);
LPBYTE pBuf = (LPBYTE)malloc(dwContentLength);
CopyMemory(&pBuf[0], szHeader, lstrlen(szHeader));
ReadFile(hFile, &pBuf[lstrlen(szHeader)], dwFileSize, &dwBytesRead, NULL);
CopyMemory(&pBuf[lstrlen(szHeader) + dwFileSize], szDataEnd, lstrlen(szDataEnd));
HttpSendRequest(hRequest, szHeaders, lstrlen(szHeaders), pBuf, dwContentLength);
CloseHandle(hFile);
free(pBuf);
}
}
InternetCloseHandle(hRequest);
}
InternetCloseHandle(hConnect);
}
InternetCloseHandle(hSession);
}