- Allowed editors: vi, vim, emacs
- All your files will be compiled on Ubuntu 14.04 LTS
- Your programs and functions will be compiled with gcc 4.8.4 using the flags -Wall -Werror -Wextra and -pedantic
- 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 malloc, free and exit. Any use of functions like printf, puts, calloc, realloc etc… is forbidden
- You are allowed to use _putchar
- You don’t have to push _putchar.c, we will use our file. If you do it won’t be taken into account
- 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 own main.c files at compilation. Our main.c files might be different from the one shown in the examples
- The prototypes of all your functions and the prototype of the function _putchar should be included in your header file called holberton.h
- Don’t forget to push your header file
- All your header files should be include guarded
- Tip: always prefer using symbolic constants (POSIX) vs numbers when it makes sense. For instance read(STDIN_FILENO, ... vs read(0, ...
0. Tread lightly, she is near
File: 0-read_textfile.c
Write a function that reads a text file and prints it to the POSIX standard output.
Prototype: ssize_t read_textfile(const char *filename, size_t letters); where letters is the number of letters it should read and print returns the actual number of letters it could read and print if the file can not be opened or read, return 0 if filename is NULL return 0 if write fails or does not write the expected amount of bytes, return 0
julien@ubuntu:~/0x15. File descriptors and permissions$ cat Requiescat
Requiescat
by Oscar Wilde
Tread lightly, she is near
Under the snow,
Speak gently, she can hear
The daisies grow.
All her bright golden hair
Tarnished with rust,
She that was young and fair
Fallen to dust.
Lily-like, white as snow,
She hardly knew
She was a woman, so
Sweetly she grew.
Coffin-board, heavy stone,
Lie on her breast,
I vex my heart alone,
She is at rest.
Peace, Peace, she cannot hear
Lyre or sonnet,
All my life's buried here,
Heap earth upon it.
julien@ubuntu:~/0x15. File descriptors and permissions$ cat 0-main.c
#include <stdio.h>
#include <stdlib.h>
#include "holberton.h"
/**
* main - check the code for Holberton School students.
*
* Return: Always 0.
*/
int main(int ac, char **av)
{
ssize_t n;
if (ac != 2)
{
dprintf(2, "Usage: %s filename\n", av[0]);
exit(1);
}
n = read_textfile(av[1], 114);
printf("\n(printed chars: %li)\n", n);
n = read_textfile(av[1], 1024);
printf("\n(printed chars: %li)\n", n);
return (0);
}
julien@ubuntu:~/0x15. File descriptors and permissions$ gcc -Wall -pedantic -Werror -Wextra 0-main.c 0-read_textfile.c -o a
julien@ubuntu:~/0x15. File descriptors and permissions$ ./a Requiescat
Requiescat
by Oscar Wilde
Tread lightly, she is near
Under the snow,
Speak gently, she can hear
The daisies grow.
(printed chars: 114)
Requiescat
by Oscar Wilde
Tread lightly, she is near
Under the snow,
Speak gently, she can hear
The daisies grow.
All her bright golden hair
Tarnished with rust,
She that was young and fair
Fallen to dust.
Lily-like, white as snow,
She hardly knew
She was a woman, so
Sweetly she grew.
Coffin-board, heavy stone,
Lie on her breast,
I vex my heart alone,
She is at rest.
Peace, Peace, she cannot hear
Lyre or sonnet,
All my life's buried here,
Heap earth upon it.
(printed chars: 468)
julien@ubuntu:~/0x15. File descriptors and permissions$ 1. Under the snow
File: 1-create_file.c
Create a function that creates a file.
- Prototype: int create_file(const char *filename, char *text_content);
- where filename is the name of the file to create and text_content is a NULL terminated string to write to the file
- Returns: 1 on success, -1 on failure (file can not be created, file can not be written, write “fails”, etc…)
- The created file must have those permissions: rw-------. If the file already exists, do not change the permissions.
- if the file already exists, truncate it
- if filename is NULL return -1
- if text_content is NULL create an empty file
julien@ubuntu:~/0x15. File descriptors and permissions$ cat 1-main.c
#include <stdio.h>
#include <stdlib.h>
#include "holberton.h"
/**
* main - check the code for Holberton School students.
*
* Return: Always 0.
*/
int main(int ac, char **av)
{
int res;
if (ac != 3)
{
dprintf(2, "Usage: %s filename text\n", av[0]);
exit(1);
}
res = create_file(av[1], av[2]);
printf("-> %i)\n", res);
return (0);
}
julien@ubuntu:~/0x15. File descriptors and permissions$ gcc -Wall -pedantic -Werror -Wextra 1-main.c 1-create_file.c -o b
julien@ubuntu:~/0x15. File descriptors and permissions$ ./b hello world
-> 1)
julien@ubuntu:~/0x15. File descriptors and permissions$ ls -l hello
-rw------- 1 julien julien 5 Dec 3 14:28 hello
julien@ubuntu:~/0x15. File descriptors and permissions$ cat hello
worldjulien@ubuntu:~/0x15. File descriptors and permis$ 2. Speak gently, she can hear
File: 2-append_text_to_file.c
Write a function that appends text at the end of a file.
- Prototype: int append_text_to_file(const char *filename, char *text_content);
- where filename is the name of the file and text_content is the NULL terminated string to add at the end of the file
- Return: 1 on success and -1 on failure
- Do not create the file if it does not exist
- If filename is NULL return -1
- If text_content is NULL, do not add anything to the file. Return 1 if the file exists and -1 if the file does not exist or if you do not have the required permissions to write the file
julien@ubuntu:~/c/curriculum_by_julien/holbertonschool-low_level_programming/0x15. File descriptors and permissions$ cat 2-main.c
#include <stdio.h>
#include <stdlib.h>
#include "holberton.h"
/**
* main - check the code for Holberton School students.
*
* Return: Always 0.
*/
int main(int ac, char **av)
{
int res;
if (ac != 3)
{
dprintf(2, "Usage: %s filename text\n", av[0]);
exit(1);
}
res = append_text_to_file(av[1], av[2]);
printf("-> %i)\n", res);
return (0);
}
julien@ubuntu:~/0x15. File descriptors and permissions$ echo -n Hello > hello
julien@ubuntu:~/0x15. File descriptors and permissions$ ls -l hello
-rw-rw-r-- 1 julien julien 5 Dec 3 14:48 hello
julien@ubuntu:~/0x15. File descriptors and permissions$ gcc -Wall -pedantic -Werror -Wextra 2-main.c 2-append_text_to_file.c -o c
julien@ubuntu:~/0x15. File descriptors and permissions$ ./c hello " World!
> "
-> 1)
julien@ubuntu:~/0x15. File descriptors and permissions$ cat hello
Hello World!
julien@ubuntu:~/0x15. File descriptors and permissions$3. cp
File: 3-cp.c
Write a program that copies the content of a file to another file.
- Usage: cp file_from file_to if the number of argument is not the correct one, exit with code 97 and print - Usage: cp file_from file_to, followed by a new line, on the POSIX standard error
- if file_to already exists, truncate it
- if file_from does not exist, or if you can not read it, exit with code 98 and print Error: Can't read from file NAME_OF_THE_FILE, followed by a new line, on the POSIX standard error
- where NAME_OF_THE_FILE is the first argument passed to your program
- if you can not create or if write to file_to fails, exit with code 99 and print Error: Can't write to NAME_OF_THE_FILE, followed by a new line, on the POSIX standard error
- where NAME_OF_THE_FILE is the second argument passed to your program
- if you can not close a file descriptor , exit with code 100 and print Error: Can't close fd FD_VALUE, followed by a new line, on the POSIX standard error where FD_VALUE is the value of the file descriptor Permissions of the created file: rw-rw-r--. If the file already exists, do not > - change the permissions
- You must read 1,024 bytes at a time from the file_from to make less system calls. - Use a buffer
- You are allowed to use dprintf
julien@ubuntu:~/0x15. File descriptors and permissions$ gcc -Wall -pedantic -Werror -Wextra 3-cp.c -o cp
julien@ubuntu:~/0x15. File descriptors and permissions$ cat incitatous
Why you should think twice before putting pictures on social media.
(What you always wanted to know about @Incitatous)
#PrivacyAware
http://imgur.com/a/Mq1tc
julien@ubuntu:~/0x15. File descriptors and permissions$ ./cp incitatous Incitatous
julien@ubuntu:~/0x15. File descriptors and permissions$ ls -l Incitatous
-rw-rw-r-- 1 julien julien 158 Dec 3 15:39 Incitatous
julien@ubuntu:~/0x15. File descriptors and permissions$ cat Incitatous
Why you should think twice before putting pictures on social media.
(What you always wanted to know about @Incitatous)
#PrivacyAware
http://imgur.com/a/Mq1tc
julien@ubuntu:~/0x15. File descriptors and permissions$