Undefined reference usb_init()

Question

I am working on customized USB driver for keyboard using libusb. I wrote a simple program and tried to compile that program i received warning and output file is not generated.

This is my program.

#include <stdio.h>
#include <libusb-1.0/libusb.h>

void main(){
  usb_init(NULL);
    return;
}

The error message is

sample.c: In function ‘main’:
sample.c:7:3: warning: implicit declaration of function ‘usb_init’ [-Wimplicit-function-declaration]
   usb_init(NULL);
   ^
/tmp/ccYbyFAK.o: In function `main':
sample.c:(.text+0xf): undefined reference to `usb_init'
collect2: error: ld returned 1 exit status

I run this commands to set the library lining flag, commands are successfully executed.

pkg-config --list-all
pkg-config --libs libusb

i tried following commands to execute my prog

gcc -o output sample.c -lusb-1.0
gcc -o output sample.c -libusb-1.0

Please help me resolve this issue

Where is libusb located? Where did you get libusb? Was it distro installed? Can you provide install instructions or a download? — jww, Apr 23 '19 at 16:56

score 0 · Accepted Answer · answered Apr 23 '19 at 18:01

You are including the header file for libusb 1.0, but you are using usb_init, a function that is not part of it's API. Note that libusb 0.1 is really old and has a different API than libusb 1.0. You should refer to the documentation of libusb 1.0 to learn what functions are supported in libusb 1.0:

https://libusb.info/

Undefined reference usb_init()

1 Answers1