How to fix this error: undefined reference to `__imp_InternetOpenA' - c++

Question

I want make C++ program where send .txt file with information to my PC. I surch so much in internet but cant find method that works.
When I uusing Dev C++ give me this errors:
...: undefined reference to __imp_InternetOpenA'
...: undefined reference to__imp_InternetConnectA'
...: undefined reference to __imp_FtpPutFileA'
...: undefined reference to__imp_HttpOpenRequestA'
Here are three examples where I find, but all return this error.
<pre>
#include <windows.h>
#include <wininet.h>
#include <iostream>
#include <stdio.h>
#include <tchar.h>
#pragma comment(lib,"wininet.lib")
#define ERROR_OPEN_FILE 10
#define ERROR_MEMORY 11
#define ERROR_SIZE 12
#define ERROR_INTERNET_OPEN 13
#define ERROR_INTERNET_CONN 14
#define ERROR_INTERNET_REQ 15
#define ERROR_INTERNET_SEND 16
using namespace std;
int main()
{
// Local variables
char filename[] = "file"; //Filename to be loaded
char filepath[] = "d:\\a.jpg"; //Filename to be loaded
char type[] = "image/jpeg";
char boundary[] = "--BOUNDARY---"; //Header boundary
char nameForm[] = "formname"; //Input form name
char iaddr[] = "localhost"; //IP address
char url[] = "/http/file.php"; //URL
char hdrs[512]={'-'}; //Headers
char * buffer; //Buffer containing file + headers
char * content; //Buffer containing file
FILE * pFile; //File pointer
long lSize; //File size
size_t result;
// Open file
pFile = fopen ( filepath , "rb" );
if (pFile==NULL)
{
printf("ERROR_OPEN_FILE");
getchar();
return ERROR_OPEN_FILE;
}
printf("OPEN_FILE\n");
// obtain file size:
fseek (pFile , 0 , SEEK_END);
lSize = ftell (pFile);
rewind (pFile);
// allocate memory to contain the whole file:
content = (char*) malloc (sizeof(char)*lSize);
if (content == NULL)
{
printf("ERROR_MEMORY");
getchar();
return ERROR_OPEN_FILE;
}
printf("MEMORY_ALLOCATED\t \"%d\" \n",&lSize);
// copy the file into the buffer:
result = fread (content,1,lSize,pFile);
if (result != lSize)
{
printf("ERROR_SIZE");
getchar();
return ERROR_OPEN_FILE;
}
printf("SIZE_OK\n");
// terminate
fclose (pFile);
printf("FILE_CLOSE\n");
//allocate memory to contain the whole file + HEADER
buffer = (char*) malloc (sizeof(char)*lSize + 2048);
//print header
sprintf(hdrs,"Content-Type: multipart/form-data; boundary=%s",boundary);
sprintf(buffer,"%s\r\nContent-Disposition: form-data; name=\"%s\"; filename=\"%
----------
s\"\r\n",boundary,nameForm,filename);
sprintf(buffer,"%sContent-Type: %s\r\n",buffer,type);
sprintf(buffer,"%s%s",buffer,content);
sprintf(buffer,"%s--%s--\r\n",buffer,boundary);
//Open internet connection
HINTERNET hSession = InternetOpen("WINDOWS",INTERNET_OPEN_TYPE_PRECONFIG, NULL, NULL, 0);
if(hSession==NULL)
{
printf("ERROR_INTERNET_OPEN");
getchar();
return ERROR_OPEN_FILE;
}
printf("INTERNET_OPENED\n");
HINTERNET hConnect = InternetConnect(hSession, iaddr,INTERNET_DEFAULT_HTTP_PORT, NULL, NULL, INTERNET_SERVICE_HTTP, 0, 1);
if(hConnect==NULL)
{
printf("ERROR_INTERNET_CONN");
getchar();
return ERROR_INTERNET_CONN;
}
printf("INTERNET_CONNECTED\n");
HINTERNET hRequest = HttpOpenRequest(hConnect, (const char*)"POST",_T(url),NULL, NULL, NULL,INTERNET_FLAG_RELOAD, 1);
if(hRequest==NULL)
{
printf("ERROR_INTERNET_REQ");
getchar();
}
printf("INTERNET_REQ_OPEN\n");
BOOL sent= HttpSendRequest(hRequest, hdrs, strlen(hdrs), buffer, strlen(buffer));
if(!sent)
{
printf("ERROR_INTERNET_SEND");
getchar();
return ERROR_INTERNET_CONN;
}
printf("INTERNET_SEND_OK\n");
//close any valid internet-handles
InternetCloseHandle(hSession);
InternetCloseHandle(hConnect);
InternetCloseHandle(hRequest);
getchar();
return 0;
}
<pre>
#include <winsock2.h>
#include <wininet.h>
#include <tchar.h>
#include <iostream>
#include <stdlib.h>
#include <windows.h>
//#pragma comment(lib,"wininet.lib")
using namespace std;
int main()
{
static TCHAR frmdata[] = "-----------------------------7d82751e2bc0858\nContent-Disposition: form-data; name=\"uploadedfile\"; filename=\"C:\test.txt\"\nContent-Type: text/plain\n\nfile contents here\n-----------------------------7d82751e2bc0858--";
static TCHAR hdrs[] = "Content-Type: multipart/form-data; boundary=---------------------------7d82751e2bc0858";
HINTERNET hSession = InternetOpen("MyAgent",INTERNET_OPEN_TYPE_PRECONFIG, NULL, NULL, 0);
if(hSession==NULL)
{
cout<<"Error: InternetOpen";
}
HINTERNET hConnect = InternetConnect(hSession, _T("localhost"),INTERNET_DEFAULT_HTTP_PORT, NULL, NULL, INTERNET_SERVICE_HTTP, 0, 1);
if(hConnect==NULL)
{
cout<<"Error: InternetConnect";
}
HINTERNET hRequest = HttpOpenRequest(hConnect, (const char*)"POST",_T("upload.php"), NULL, NULL, (const char**)"*/*\0", 0, 1);
if(hRequest==NULL)
{
cout<<"Error: HttpOpenRequest";
}
BOOL sent= HttpSendRequest(hRequest, hdrs, strlen(hdrs), frmdata, strlen(frmdata));
if(!sent)
{
cout<<"Error: HttpSendRequest";
}
//close any valid internet-handles
InternetCloseHandle(hSession);
InternetCloseHandle(hConnect);
InternetCloseHandle(hRequest);
return 0;
}
#include <windows.h>
#include <wininet.h>
#include <stdio.h>
#include <iostream>
#define ERROR_OPEN_FILE 10
#define ERROR_MEMORY 11
#define ERROR_SIZE 12
#define ERROR_INTERNET_OPEN 13
#define ERROR_INTERNET_CONN 14
#define ERROR_INTERNET_REQ 15
#define ERROR_INTERNET_SEND 16
using namespace std;
int main()
{
// Local variables
static char filename[] = "test.txt"; //Filename to be loaded
static char type[] = "image/jpg";
static char boundary[] = "pippo"; //Header boundary
static char nameForm[] = "uploadedfile"; //Input form name
static char iaddr[] = "localhost"; //IP address
static char url[] = "test.php"; //URL
char hdrs[255]; //Headers
char * buffer; //Buffer containing file + headers
char * content; //Buffer containing file
FILE * pFile; //File pointer
long lSize; //File size
size_t result;
// Open file
pFile = fopen ( filename , "rb" );
if (pFile==NULL) return ERROR_OPEN_FILE;
// obtain file size:
fseek (pFile , 0 , SEEK_END);
lSize = ftell (pFile);
rewind (pFile);
// allocate memory to contain the whole file:
content = (char*) malloc (sizeof(char)*lSize);
if (content == NULL) return ERROR_MEMORY;
// copy the file into the buffer:
result = fread (content,1,lSize,pFile);
if (result != lSize) return ERROR_SIZE;
// terminate
fclose (pFile);
//allocate memory to contain the whole file + HEADER
buffer = (char*) malloc (sizeof(char)*lSize + 2048);
//print header
sprintf(hdrs,"Content-Type: multipart/form-data; boundary=%s",boundary);
sprintf(buffer,"--%s\r\nContent-Disposition: form-data; name=\"%s\"; filename=\"%s\"\r\n",boundary,nameForm,filename);
sprintf(buffer,"%sContent-Type: %s\r\n\r\n",buffer,type);
sprintf(buffer,"%s%s\r\n",buffer,content);
sprintf(buffer,"%s--%s--\r\n",buffer,boundary);
//Open internet connection
HINTERNET hSession = InternetOpen("WinSock",INTERNET_OPEN_TYPE_PRECONFIG, NULL, NULL, 0);
if(hSession==NULL) return ERROR_INTERNET_OPEN;
HINTERNET hConnect = InternetConnect(hSession, iaddr,INTERNET_DEFAULT_HTTP_PORT, NULL, NULL, INTERNET_SERVICE_HTTP, 0, 1);
if(hConnect==NULL) return ERROR_INTERNET_CONN;
HINTERNET hRequest = HttpOpenRequest(hConnect, (const char*)"POST",url, NULL, NULL, (const char**)"*/*\0", 0, 1);
if(hRequest==NULL) return ERROR_INTERNET_REQ;
BOOL sent= HttpSendRequest(hRequest, hdrs, strlen(hdrs), buffer, strlen(buffer));
if(!sent) return ERROR_INTERNET_SEND;
//close any valid internet-handles
InternetCloseHandle(hSession);
InternetCloseHandle(hConnect);
InternetCloseHandle(hRequest);
return 0;
}
</pre>

Answer 1

I had many errors like this on my first C++ program. It is a problem with linking against the WinINet library. If you are using MinGW add "-lwininet" (without quotes) to the additional commandling arguments and it should be fixed. I don't know what to to do if you use VC++. Also, make sure the location of the WinINet library is in the linker's search paths.

Answer 2

With CMake you simply need
target_link_libraries( MY_TARGET
ws2_32)