Pokémon Database: File I/O Implementation in C

/*****************************************************************
//
//  Function name: writefile
//
//  DESCRIPTION:   This function writes the Pokemon data stored 
//                 in the array to a file. If the file exists, 
//                 then it will be overwritten.
//
//  Parameters:    pokearray (struct pokemon[]) : array of Pokemon to write
//                 num (int)                    : number of Pokemon to write
//                 filename (char[])            : name of the file to write to
//
//  Return values:  0 : success
//                 -1 : error (file could not be opened)
//
****************************************************************/

int writefile(struct pokemon pokearray[], int num, char filename[])
{  
    /* Open the writefile (file will be overwritten if already exists) */
    FILE *pokemonFile = fopen(filename, "w");
    
    int i = 0;

    /* Check if file was successfully opened */
    if (pokemonFile == NULL) 
    {
        return -1; /* return if file could not be opened */
    }
    
    /* Loop the array of pokemons and write their data to the file */
    for (i = 0; i < num; i++) 
    {
        fprintf(pokemonFile, "%d\n", pokearray[i].level); /* Write the Pokemon's level */
        fprintf(pokemonFile, "%s\n", pokearray[i].name); /* Write the Pokemon's name */
    }
    
    /* Close the file so that all of the data is written */
    fclose(pokemonFile);
    return 0;
}

/*****************************************************************
//
//  Function name: readfile
//
//  DESCRIPTION:   This function reads the Pokemon data from a file
//                 and stores it in an array. It stops reading if it 
//                 reaches the maximum array size or the end of the 
//                 file. 
//
//  Parameters:    pokearray (struct pokemon[]) : array to store Pokemon data
//                 num (int*)                   : pointer to the number of Pokemon
//                 filename (char[])            : name of the file to read from
//
//  Return values:  0 : success
//                 -1 : error (file could not be opened)
//
****************************************************************/

int readfile(struct pokemon pokearray[], int *num, char filename[])
{
    int i = 0; /* Counter to how many pokemons have been read so far */

    /* Open the readfile (read it from an existing file) */
    FILE *pokemonFile = fopen(filename, "r");

    /* If fopen returns NULL, then the file was unable to open so return -1 */
    if (pokemonFile == NULL) 
    {
        return -1;
    }

    /* Loop through to read the data from the file. Either read the max number of pokemons or until it reaches the end of the file */
    while (i < *num && fscanf(pokemonFile, "%d\n", &pokearray[i].level) != EOF && fgets(pokearray[i].name, sizeof(pokearray[i].name), pokemonFile) != NULL) 
    {
        /* Remove the newline character from the name, if there is one */
        if (pokearray[i].name[strlen(pokearray[i].name) - 1] == '\n')
        {
            pokearray[i].name[strlen(pokearray[i].name) - 1] = '\0';
        }
        i++;
    }
    
    /* Update the num variable so we can see how many pokemons were read */
    *num = i;
    
    /*Close the file to make sure that all the data is saved and is properly closed */
    fclose(pokemonFile);

    return 0;
}