// Copyright 2016 The Emscripten Authors. All rights reserved.

// Emscripten is available under two separate licenses, the MIT license and the

// University of Illinois/NCSA Open Source License. Both these licenses can be

// found in the LICENSE file.

#include <assert.h>

#include <stdio.h>

#include <stdlib.h>

#include <string.h>

#include <emscripten/emscripten.h>

void create_file()

{

FILE *file = fopen("hello_file.txt", "wb");

assert(file);

const char *data = "Hello world";

const char *data2 = "da";

const char *data3 = "ta!";

fwrite(data, 1, strlen(data), file);

fseek(file, 8, SEEK_SET);

fwrite(data3, 1, strlen(data3), file);

fseek(file, 6, SEEK_SET);

fwrite(data2, 1, strlen(data2), file);

fclose(file);

}

void read_file()

{

FILE *file = fopen("hello_file.txt", "rb");

char buffer[128] = {};

size_t read = fread(buffer, 1, sizeof(buffer), file);

printf("read %u bytes. Result: %s\n", (unsigned int)read, buffer);

assert(read == strlen("Hello data!"));

assert(!strcmp(buffer, "Hello data!"));

}

int main()

{

create_file();

read_file();

return 0;

}