我正在尝试编译这段非常简单的代码。我从命令行对GCC相当陌生，所以请原谅我。我用 GCC 尝试了很多不同的东西，但我仍然无法编译它。我确实安装了libusb。我怎样才能让这段代码编译？
图书馆：
anything:usb mymac$ brew list libusb
/usr/local/Cellar/libusb/1.0.9/include/libusb-1.0/libusb.h
/usr/local/Cellar/libusb/1.0.9/lib/libusb-1.0.0.dylib
/usr/local/Cellar/libusb/1.0.9/lib/pkgconfig/libusb-1.0.pc
/usr/local/Cellar/libusb/1.0.9/lib/ (2 other files)
anything:usb mymac$
GCC 尝试（全部失败）：
gcc -o xout usbtest.c
gcc -o xout usbtest.c -lusb-1.0
gcc -L/usr/local/Cellar/libusb/1.0.9/lib -o xout usbtest.c -lusb-1.0
所有尝试的错误：
usbtest.c:3:10: fatal error: 'libusb.h' file not found
#include <libusb.h>
代码：
#include <stdio.h>
#include <stdlib.h>
#include <libusb.h>
int main(int argc, const char * argv[])
{
libusb_device **devs;
libusb_context *context = NULL;
size_t list;
//size_t i;
int ret;
ret = libusb_init(&context);
if(ret < 0)
{
perror("libusb_init");
exit(1);
}
list = libusb_get_device_list(context, &devs);
printf("There are %zd devices found\n", list);
return 0;
}