Setup

g01c starts from the complete g01a terminal game. If you followed the journey path, you have it. If you are starting independently, the g01a companion repo contains the full solution.

Starting point

Your working directory must contain these files before you begin:

main.c
load.c
display.c
game.c
game.h
questions.txt
Makefile
libtci/          (your c01 build, or a copy)

Verify the build:

make re
./game questions.txt

The game must run and respond to input before you add music to it.

Install aplay

aplay is part of the ALSA utilities package. Install it if it is not already present:

sudo apt install alsa-utils
aplay --version

aplay plays WAV files from the command line. It will be the child process that our game spawns to handle audio.

Get the WAV files

You need three royalty-free WAV files — one per tier. Search Freesound.org for tracks licensed CC0 or CC BY. What to look for:

Download each track and convert it to WAV if necessary (ffmpeg -i input.mp3 output.wav). Trim each track to a clean loop of 30–90 seconds using Audacity or sox.

Create a music/ directory and place the three files there:

mkdir music
cp ~/Downloads/calm_loop.wav   music/tier1.wav
cp ~/Downloads/tense_loop.wav  music/tier2.wav
cp ~/Downloads/finale_loop.wav music/tier3.wav

Create the new files

Create two empty files for the music module:

touch music.c music.h

Add music.h to game.h

Open game.h and add the include for the music header immediately after the existing system includes, before the LEVELS definition:

# include "music.h"

music.h does not exist yet — the next page defines it. The include goes in game.h so that game.c picks it up automatically (it already includes game.h).

Update the Makefile

Add music.c to the source list:

SRCS = main.c load.c display.c game.c music.c

The %.o: %.c game.h rule already recompiles every object when game.h changes, so no other Makefile change is needed.

Build check

The build will fail until music.c and music.h have valid content — the compiler will complain about the missing include. Add stubs now so the build stays clean while you work through the pages:

music.h (stub):

#ifndef MUSIC_H
# define MUSIC_H
 
# include <sys/types.h>
 
pid_t  start_music(const char *path);
void   stop_music(pid_t pid);
 
#endif

music.c (stub):

#include "music.h"
 
pid_t  start_music(const char *path)
{
    (void)path;
    return (-1);
}
 
void   stop_music(pid_t pid)
{
    (void)pid;
}

make re

The game must build cleanly with zero warnings. Music will not play yet — start_music returns -1 — but the binary works.