First function runs - never called - node.js

Question

I am working through smashing node.js - the first book example shows a function that brings in all the current directory files into a list, then file(i) is run, without it being called. I don't know why? - the input parameter to the function is used within the program and incremented as well, but where does this value come from? How is this function called in the first place?
/**
* Module dependencies.
*/
var fs = require('fs')
, stdin = process.stdin
, stdout = process.stdout
/**
* Read the current directory.
*/
fs.readdir(__dirname, function (err, files) {
console.log('');
if (!files.length) {
return console.log(' \033[31m No files to show!\033[39m\n');
}
console.log(' Select which file or directory you want to see\n');
// called for each file walked in the directory
var stats = {};
function file(i) {
var filename = files[i];
fs.stat(__dirname + '/' + filename, function (err, stat) {
stats[i] = stat;
if (stat.isDirectory()) {
console.log(' '+i+' \033[36m' + filename + '/\033[39m');
} else {
console.log(' '+i+' \033[90m' + filename + '\033[39m');
}
if (++i == files.length) {
read();
} else {
file(i);
}
});
}
// read user input when files are shown
function read () {
console.log('');
stdout.write(' \033[33mEnter your choice: \033[39m');
stdin.resume();
stdin.setEncoding('utf8');
stdin.on('data', option);
}
// called with the option supplied by the user
function option (data) {
var filename = files[Number(data)];
if (!filename) {
stdout.write(' \033[31mEnter your choice: \033[39m');
} else {
stdin.pause();
if (stats[Number(data)].isDirectory()) {
fs.readdir(__dirname + '/' + filename, function (err, files) {
console.log('');
console.log(' (' + files.length + ' files)');
files.forEach(function (file) {
console.log(' - ' + file);
});
console.log('');
});
} else {
fs.readFile(__dirname + '/' + filename, 'utf8', function (err, data) {
console.log('');
console.log('\033[90m' + data.replace(/(.*)/g, ' $1') + '\033[39m');
});
}
}
}
// start by walking the first file
file(0);
});

Answer 1

I must be misunderstanding your question... cuz it seems to straightforward.
The line at the bottom:
// start by walking the first file
file(0);
Is the line the "kicks-off" the file(i) chain. That line is at the bottom of the callback of the fs.readdir and is called when it gets to that point after defining the other functions and variables in the main body of the fs.readdir callback.
Am I missing something to your question?