#include <stdio.h>
#include <stdlib.h>
#include <fcntl.h>
#include <unistd.h>
#include <linux/input.h>

#define MOUSEFILE "/dev/input/mouse1"
//
int main()
{
    int fd;
    struct input_event ie;
    //
    unsigned char button,bLeft,bMiddle,bRight;
    char x,y;
    int absolute_x,absolute_y;

    if((fd = open(MOUSEFILE, O_RDONLY)) == -1) {
        printf("Device open ERROR\n");
        exit(EXIT_FAILURE);
    }
    else
    {
        printf("Device open OK\n");
    }
    //
    printf("right-click to set absolute x,y coordinates origin (0,0)\n");
    while(read(fd, &ie, sizeof(struct input_event)))
    {
        unsigned char *ptr = (unsigned char*)&ie;
        int i;       
        //
        button=ptr[0];
        bLeft = button & 0x1;
        bMiddle = ( button & 0x4 ) > 0;
        bRight = ( button & 0x2 ) > 0;
        x=(char) ptr[1];y=(char) ptr[2];
        // printf("bLEFT:%d, bMIDDLE: %d, bRIGHT: %d, rx: %d  ry=%d\n",bLeft,bMiddle,bRight, x,y);
        //
        absolute_x+=x;
        absolute_y-=y;
        if (bRight==1)
        {
            absolute_x=0;
            absolute_y=0;
            printf("Absolute x,y coords origin recorded\n");
        }
        //
        printf("Absolute coords from TOP_LEFT= %i %i\n",absolute_x,absolute_y);
        //
        // comment to disable the display of raw event structure datas
        //
        for(i=0; i<sizeof(ie); i++)
        {
            printf("%02X ", *ptr++);
        }
        printf("\n");
    }

return 0;
}