OK, habs selbst hinbekommen:

Code:
#include <stdio.h>
#include <stdlib.h>
main(){
	FILE *fmouse;
	char b[3];
	fmouse = fopen("/dev/input/mice","r");
	int xd=0,yd=0; //x/y movement delta
	int xo=0,yo=0; //x/y overflow (out of range -255 to +255)
	int lb=0,mb=0,rb=0; //left/middle/right mousebutton
	while(!mb){
		fread(b,sizeof(char),3,fmouse);
		lb=(b[0]&1)>0;
		rb=(b[0]&2)>0;
		mb=(b[0]&4)>0;
		xo=(b[0]&64)>0;
		yo=(b[0]&128)>0;
		xd=b[1];
		yd=b[2];
		printf("lb=%d rm=%d mb=%d xo=%d yo=%d xd=%d yd=%d\n",lb,rb,mb,xo,yo,xd,yd);
	}
	fclose(fmouse);
}
PS: konnts nur mit sudo aufrufen, ansonsten gabs nen segfault.