Compiler Error while using libusb.h

Question

I am writing a program in QT in C++. I am using the library libusb.h. Below is my code -

libusb_device **devs;
libusb_device_handle *dev_handle;
libusb_context *ctx = NULL;
int r;
ssize_t cnt; 
r = libusb_init(&ctx); 
if(r < 0) {
        cout<<"Init Error "<<r<<endl; //there was an error
        return 1;
    }

But when I want to build it, the errors is occur.

/home/test/main.cpp:12: błąd: undefined reference to `libusb_init'

This is file.pro

QT += core
QT -= gui

TARGET = test
CONFIG += console
CONFIG -= app_bundle

TEMPLATE = app

SOURCES += main.cpp

Can someone help me pointing out the mistake in my code above?

You need to link to the libusb as well – hellow Jul 10 '18 at 11:49 — hellow, Jul 10 '18 at 11:49
`LIBS += -libusb-1.0` should work (not sure) – hellow Jul 10 '18 at 11:51 — hellow, Jul 10 '18 at 11:51
`LIBS += -lusb-1.0` worked for me – Juliette Marquis Feb 07 '19 at 11:21 — Juliette Marquis, Feb 07 '19 at 11:21

score 1 · Answer 1 · answered Aug 18 '19 at 21:21

1

That's a link error.

Add the following to your project (.pro) file. Do not forget to edit library path and library name according to your own setup.

INCLUDEPATH += "/usr/local/include/libusb-1.0"
LIBS += -L"/usr/lib" -l"usb-1.0"

answered Aug 18 '19 at 21:21

Nazım Gediz Aydındoğmuş

176
4
9

score 0 · Answer 2 · answered Jul 10 '18 at 09:48

0

You didn't

#include "libusb.h"

or

#include <libusb.h>

answered Jul 10 '18 at 09:48

Goswin von Brederlow

11,875
2
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I included two librarys #include #include – P.Wujek Jul 10 '18 at 10:28
Well, not in the source you gave. If you included it then you don't link it. Most libraries are not just their header. – Goswin von Brederlow Jul 10 '18 at 10:33
`undefined reference` indicates a missing library instead of a missing header. But yes, no `include` is given in the question, you're right about that. – hellow Jul 10 '18 at 11:49

Compiler Error while using libusb.h

2 Answers2