GCC C code for MIDI visual output for sliders/knobs/keys

/*
 * Copyright (c) 2017 Kris Occhipint.
 * http://filmsbykris.com
 *
 * Displays a visual output for midi input value of sliders/knobs/buttons
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, version 3.
 *
 * This program is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
 * General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program. If not, see <http://www.gnu.org/licenses/>.
 */
#include <sys/soundcard.h>
#include <fcntl.h>
#include <unistd.h>
#include <stdio.h>

//#define  DEVICE  "/dev/sequencer"
#define  DEVICE  "/dev/midi4"


int main(void) {
   unsigned char input[4];

   // open the midi device for reading.
   int seqfd = open(DEVICE, O_RDONLY);
   if (seqfd == -1) {
      printf("Error: cannot open %s\n", DEVICE);
      return 1;
   }

   // wait for MIDI input and print it to the screen.
   while (1) {
      read(seqfd, &input, sizeof(input));
      //print what key/knob/slider is being pressed and at what value
      fflush(stdout);
      printf("\rMIDI byte: %d - %d", input[1], input[2]);
      for (int i = 0;i<=input[2];i++){
        printf("=");
      }
      fflush(stdout);
      printf("\r                                                                                                                                                              ");
   }

   return 0;
}