- By Julien Barbier
Read or watch:
- 0x0d. Structures.pdf
- struct (C programming language)
- Documentation: structures
- 0x0d. Typedef and structures.pdf
- typedef
- Programming in C by Stephen Kochan - Chapter 8, Working with Structures p163-189
- The Lost Art of C Structure Packing (Advanced - not mandatory)
At the end of this project, you are expected to be able to explain to anyone, without the help of Google:
- What are structures, when, why and how to use them
- How to use
typedef
- Allowed editors:
vi
,vim
,emacs
- All your files will be compiled on Ubuntu 20.04 LTS using
gcc
, using the options-Wall -Werror -Wextra -pedantic -std=gnu89
- All your files should end with a new line
- A
README.md
file, at the root of the folder of the project is mandatory - Your code should use the
Betty
style. It will be checked using betty-style.pl and betty-doc.pl - You are not allowed to use global variables
- No more than 5 functions per file
- The only C standard library functions allowed are
printf
,malloc
,free
andexit
. - In the following examples, the
main.c
files are shown as examples. You can use them to test your functions, but you don't have to push them to your repo (if you do we won't take them into account). We will use our ownmain.c
files at compilation. Ourmain.c
files might be different from the one shown in the examples - Don't forget to push your header file
- All your header files should be include guarded
mandatory
Define a new type struct dog
with the following elements:
name
, type =char *
age
, type =float
owner
, type =char *
julien@ubuntu:~/0x0d. structures, typedef$ cat 0-main.c
#include <stdio.h>
#include "dog.h"
/**
* main - check the code
*
* Return: Always 0.
*/
int main(void)
{
struct dog my_dog;
my_dog.name = "Poppy";
my_dog.age = 3.5;
my_dog.owner = "Bob";
printf("My name is %s, and I am %.1f :) - Woof!\n", my_dog.name, my_dog.age);
return (0);
}
julien@ubuntu:~/0x0d. structures, typedef$ gcc -Wall -pedantic -Werror -Wextra -std=gnu89 0-main.c -o a
julien@ubuntu:~/0x0d. structures, typedef$ ./a
My name is Poppy, and I am 3.5 :) - Woof!
julien@ubuntu:~/0x0d. structures, typedef$
Repo:
- GitHub repository:
alx-low_level_programming
- Directory:
0x0E-structures_typedef
- File:
dog.h
mandatory
Write a function that initialize a variable of type struct dog
- Prototype:
void init_dog(struct dog *d, char *name, float age, char *owner);
julien@ubuntu:~/0x0d. structures, typedef$ cat 1-main.c
#include <stdio.h>
#include "dog.h"
/**
* main - check the code
*
* Return: Always 0.
*/
int main(void)
{
struct dog my_dog;
init_dog(&my_dog, "Poppy", 3.5, "Bob");
printf("My name is %s, and I am %.1f :) - Woof!\n", my_dog.name, my_dog.age);
return (0);
}
julien@ubuntu:~/0x0d. structures, typedef$ gcc -Wall -pedantic -Werror -Wextra -std=gnu89 1-main.c 1-init_dog.c -o b
julien@ubuntu:~/0x0d. structures, typedef$ ./b
My name is Poppy, and I am 3.5 :) - Woof!
julien@ubuntu:~/0x0d. structures, typedef$
Repo:
- GitHub repository:
alx-low_level_programming
- Directory:
0x0E-structures_typedef
- File:
1-init_dog.c
2. A dog will teach you unconditional love. If you can have that in your life, things won't be too bad
mandatory
Write a function that prints a struct dog
- Prototype:
void print_dog(struct dog *d);
- Format: see example bellow
- You are allowed to use the standard library
- If an element of
d
isNULL
, print(nil)
instead of this element. (ifname
isNULL
, printName: (nil)
) - If
d
isNULL
print nothing.
julien@ubuntu:~/0x0d. structures, typedef$ cat 2-main.c
#include <stdio.h>
#include "dog.h"
/**
* main - check the code
*
* Return: Always 0.
*/
int main(void)
{
struct dog my_dog;
my_dog.name = "Poppy";
my_dog.age = 3.5;
my_dog.owner = "Bob";
print_dog(&my_dog);
return (0);
}
julien@ubuntu:~/0x0d. structures, typedef$ gcc -Wall -pedantic -Werror -Wextra -std=gnu89 2-main.c 2-print_dog.c -o c
julien@ubuntu:~/0x0d. structures, typedef$ ./c
Name: Poppy
Age: 3.500000
Owner: Bob
julien@ubuntu:~/0x0d. structures, typedef$
Repo:
- GitHub repository:
alx-low_level_programming
- Directory:
0x0E-structures_typedef
- File:
2-print_dog.c
mandatory
Define a new type dog_t
as a new name for the type struct dog
.
julien@ubuntu:~/0x0d. structures, typedef$ cat 3-main.c
#include <stdio.h>
#include "dog.h"
/**
* main - check the code
*
* Return: Always 0.
*/
int main(void)
{
dog_t my_dog;
my_dog.name = "Poppy";
my_dog.age = 3.5;
my_dog.owner = "Bob";
printf("My name is %s, and I am %.1f :) - Woof!\n", my_dog.name, my_dog.age);
return (0);
}
julien@ubuntu:~/0x0d. structures, typedef$ gcc -Wall -pedantic -Werror -Wextra -std=gnu89 3-main.c -o d
julien@ubuntu:~/0x0d. structures, typedef$ ./d
My name is Poppy, and I am 3.5 :) - Woof!
julien@ubuntu:~/0x0d. structures, typedef$
Repo:
- GitHub repository:
alx-low_level_programming
- Directory:
0x0E-structures_typedef
- File:
dog.h
mandatory
Write a function that creates a new dog.
- Prototype:
dog_t *new_dog(char *name, float age, char *owner);
- You have to store a copy of
name
andowner
- Return
NULL
if the function fails
julien@ubuntu:~/0x0d. structures, typedef$ cat 4-main.c
#include <stdio.h>
#include "dog.h"
/**
* main - check the code
*
* Return: Always 0.
*/
int main(void)
{
dog_t *my_dog;
my_dog = new_dog("Poppy", 3.5, "Bob");
printf("My name is %s, and I am %.1f :) - Woof!\n", my_dog->name, my_dog->age);
return (0);
}
julien@ubuntu:~/0x0d. structures, typedef$ gcc -Wall -pedantic -Werror -Wextra -std=gnu89 4-main.c 4-new_dog.c -o e
julien@ubuntu:~/0x0d. structures, typedef$ ./e
My name is Poppy, and I am 3.5 :) - Woof!
julien@ubuntu:~/0x0d. structures, typedef$
Repo:
- GitHub repository:
alx-low_level_programming
- Directory:
0x0E-structures_typedef
- File:
4-new_dog.c
5. How many legs does a dog have if you call his tail a leg? Four. Saying that a tail is a leg doesn't make it a leg
mandatory
Write a function that frees dogs.
- Prototype:
void free_dog(dog_t *d);
julien@ubuntu:~/0x0d. structures, typedef$ cat 5-main.c
#include <stdio.h>
#include "dog.h"
/**
* main - check the code
*
* Return: Always 0.
*/
int main(void)
{
dog_t *my_dog;
my_dog = new_dog("Poppy", 3.5, "Bob");
printf("My name is %s, and I am %.1f :) - Woof!\n", my_dog->name, my_dog->age);
free_dog(my_dog);
return (0);
}
julien@ubuntu:~/0x0d. structures, typedef$ gcc -Wall -pedantic -Werror -Wextra -std=gnu89 5-main.c 5-free_dog.c 4-new_dog.c -o f
julien@ubuntu:~/0x0d. structures, typedef$ valgrind ./f
==22840== Memcheck, a memory error detector
==22840== Copyright (C) 2002-2015, and GNU GPL'd, by Julian Seward et al.
==22840== Using Valgrind-3.11.0 and LibVEX; rerun with -h for copyright info
==22840== Command: ./f
==22840==
My name is Poppy, and I am 3.5 :) - Woof!
==22840==
==22840== HEAP SUMMARY:
==22840== in use at exit: 0 bytes in 0 blocks
==22840== total heap usage: 4 allocs, 4 frees, 1,059 bytes allocated
==22840==
==22840== All heap blocks were freed -- no leaks are possible
==22840==
==22840== For counts of detected and suppressed errors, rerun with: -v
==22840== ERROR SUMMARY: 0 errors from 0 contexts (suppressed: 0 from 0)
julien@ubuntu:~/0x0d. structures, typedef$
Repo:
- GitHub repository:
alx-low_level_programming
- Directory:
0x0E-structures_typedef
- File:
5-free_dog.c