QtCreator and cURL - final showdown.

jareq000

Hi.
I read a hundred sites.
I try to run libraries third day.
But I can't run my code.

I work on Windows 7 64bit
"Tutorial":http://howtofix.pro/tutorial-libcurl-on-qt-creator-with-mingw/
"Qt 5.3.1 for Windows 32-bit (MinGW 4.8.2, OpenGL) ":http://download.qt-project.org/official_releases/qt/5.3/5.3.1/qt-opensource-windows-x86-mingw482_opengl-5.3.1.exe
"Win - MinGW64 7.34.0 devel SSL SSH Günter Knauf":http://curl.haxx.se/gknw.net/7.34.0/dist-w64/curl-7.34.0-devel-mingw64.7z

.pro file:
@TEMPLATE = app
CONFIG += console
CONFIG -= app_bundle

SOURCES += main.cpp

INCLUDEPATH += C:\Qt\Qt5.3.1\5.3\curl-7.34.0-devel-mingw64\include\curl
LIBS += -LC:\Qt\Qt5.3.1\5.3\curl-7.34.0-devel-mingw64\lib64 -lcurl
#LIBS += -LC:\Qt\Qt5.3.1\5.3\curl-7.34.0-devel-mingw64\lib64\libcurldll.a -this also didn't work
@

.cpp file:
@#define CURL_STATICLIB
#include <stdio.h>
#include <curl.h>
#include <easy.h>
#include <string>

size_t write_data(void *ptr, size_t size, size_t nmemb, FILE *stream) {
size_t written;
written = fwrite(ptr, size, nmemb, stream);
return written;
}

int main(void) {
CURL *curl;
FILE *fp;
CURLcode res;
char *url = "http://localhost/aaa.txt";
char outfilename[FILENAME_MAX] = "C:\bbb.txt";
curl = curl_easy_init();
if (curl) {
fp = fopen(outfilename,"wb");
curl_easy_setopt(curl, CURLOPT_URL, url);
curl_easy_setopt(curl, CURLOPT_WRITEFUNCTION, write_data);
curl_easy_setopt(curl, CURLOPT_WRITEDATA, fp);
res = curl_easy_perform(curl);
curl_easy_cleanup(curl);
fclose(fp);
}
return 0;
}
@

Always
"error: undefined reference to curl_easy_init'" "error: undefined reference to curl_easy_setopt'"
"error: undefined reference to `curl_easy_perform'"

I add and link libraries.
I add "#define CURL_STATICLIB"
I copy libcurl dll files to Qt project Release/Debug
but it didn't work.

Please help.

sierdzio

Your libraries are binary incompatible: you are trying to link a 64 bit library to a 32 bit program. That will not work. Arhcitectures and compilers must match.

jareq000

I tried compile program with MinGW64. Win32 - MSVC also didn't work.
I don't know, why there is no cURL MinGW32.

sierdzio

Compile curl yourself, using the compiler from Qt package, then compile your application using the same compiler.

jareq000

I find cURL MinGW32 - didn't work. The same fail.
I don't know, how to compile this. It is difficult for me.
I must download Source Archives - curl 7.37.1.zip, yes?
I need to use QtCreator or only MinGW and command line?

sierdzio

Then maybe easier option is to download the 64 bit Qt package?

jareq000

Yes, but MinGW is only in version Qt 32b. I don't know why.

Erlier I have a problem with version Qt VS, programs didn't compile, so I download MinGW. But some problems still are.

sierdzio

I'm so happy to be developing on Linux ;-) Problems like that are pretty much unheard of here.

Maybe there were problems with MinGW64 on Windows, so they have dropped the package, I don't know. You can try compiling Qt yourself, although it's not so easy on Windows.

jareq000

So, now:
Qt, MinGW and cURL are for Windows 32-bit, and problem is not solved. Why?
I need to add some packages?
Do I something wrong?

sierdzio

They might have been compiled using different version of MinGW. Some versions are not compatible with one another...

or something else is wrong. One thing is certain: the error you are getting is a linker error, so there is no bug on the C++ side.

jareq000

Problem solved, but not completly.
All libcurl sources I moved to project folder, and I add:
@INCLUDEPATH += C:...\curl-7.34.0-devel-mingw32\include
LIBS += C:...\curl-7.34.0-devel-mingw32\lib\libcurldll.a
LIBS += C:...\curl-7.34.0-devel-mingw32\lib\libcurl.a
@
But programs exited with code -1073741515, what is the same as 0xC0000135 -> problem with dependency...

The Fight Continues...

SGaist

Hi,

You're application is probably not finding the libcurld dll. In Qt Creator go to Project -> run -> PATH and add the path to the folder containing the curl dll

jareq000

I added path the libcurl dll (to Projects -> Run -> Run Environment -> Path), but nothing changes.
Still " programs exited with code -1073741515"

sierdzio

What happens when you run with the debugger?

jareq000

"The gdb process terminated unexpectedely (code 0)"
"Cannot continue debugged process: The program is not being run"
and
"During startup program exited with code 0xc0000135"

Even when I close the terminal window, program is still running (when I want to quit Qt I get a message "Do you want to force quit untitled.exe?)

jareq000

I installed Qt Creator 64 bit, Visual Studio 2013, cURL 64bit, and I have
"Cannot obtain a handle to the inferior: The parameter is incorrect."
So I cleaning project, and again
"exited with code -1073741515"

Files are now in release folder
@INCLUDEPATH += C:\Users...\build-one-Qt_64bit-Release\curl-7.34.0-devel-mingw64\include
LIBS += C:\Users...\build-one-Qt_64bit-Release\curl-7.34.0-devel-mingw64\lib64\libcurldll.a
LIBS += C:\Users...\build-one-Qt_64bit-Release\curl-7.34.0-devel-mingw64\lib64\libcurl.a
@

Any suggestions?

Edit:
Qt ask about "curl.lib", so I find it and copy to lib files.
Now Qt want "curldll.lib" and these file I can't find.
Why are they needed? .dll files are not enough?

jareq000

Finally, problem solved.
I run untitled.exe form explorer, and message shown, which dll is necessary.
So I download some dll's and it's work.
Thanks for response.