#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <string.h>

int function1(int argument) 
{ 
    int * p = (int *)malloc(sizeof(int));
    int k[10];

    printf("%s\n", __FUNCTION__); 
    free(p);
    
    return argument; 
}

struct Document
{
    int i;
    struct Document * head;
    struct Document * tail;
    
    //int foo(int argument) { printf("%s\n", __FUNCTION__); return argument; }
};

int function2(int argument) 
{ 
    int * p = (int *)malloc(sizeof(int));
    int k[10];

    printf("%s\n", __FUNCTION__); 
    
    return argument; 
}

struct Document * bar()
{
    struct Document * document = (struct Document *)malloc(sizeof(struct Document));
    
    // cycle
    document->head = (struct Document *)malloc(sizeof(struct Document));
    document->head->head = (struct Document *)malloc(sizeof(struct Document));
    document->head->head->head = document;
    
    return document;
}

const char * const text1 = "Is this on?";
int const array1[] = {1, 2, 3, 4, 5};

int main()
{
    typedef int (*function3_t)(int argument);

    function3_t function3 = function2;

    int temporary = 1;
    
    struct Document * document = (struct Document *)calloc(10, sizeof(struct Document));
    document = (struct Document *)realloc(document, sizeof(struct Document) * 20);
    
    printf("%i\n", 1);
    struct Document * result = bar();//->foo(temporary);
    printf("%i\n", 2);
    
    printf("%d\n", ++ document[18].i);
    printf("%p\n", document[18].head);
    printf("%p\n", document[18].tail);

    function1(1);
    function2(1);
    
    const char * const text2 = "Is this on?";
    static int const array2[] = {1, 2, 3, 4, 5};
    
    char * text3 = strdup(text2);
        
    printf("%s\n", text2);
    printf("The magic number is: %i\n", 3.1416);

    memcpy(text3, text2, strlen(text2));
    printf("text3 = %s\n", text3);

    memset(text3, 0, strlen(text2));
    printf("text3 = %s\n", text3);
    
    text3 = strndup(text2, 50);
    printf("text3 = %s\n", text3);
    
    text3 = NULL;
    
    char buffer[256];
    const char * cwd = getcwd(buffer, sizeof(buffer));
    
    printf("cwd = %s\n", cwd);

    const char * const text4 = strdup(cwd);

    printf("text4 = %s\n", text4);
}