change socket to O_NONBLOCK

src/main.c

@@ -10,6 +10,7 @@
 #include <sys/ioctl.h>
 #include <sys/socket.h>
 #include <net/if.h>
+#include <fcntl.h>
 
 const int digit_bitmaps[10][5][3] = {
         {{1,1,1},{1,0,1},{1,0,1},{1,0,1},{1,1,1}}, // 0
@@ -394,6 +395,7 @@ int main(int argc, char **argv) {
                         perror("socket error");
                         return 1;
                 }
+                fcntl(soc, F_SETFL, O_NONBLOCK);
                 strcpy(ifr.ifr_name, "can0");
                 ioctl(soc, SIOCGIFINDEX, &ifr);
                 addr.can_family = AF_CAN;