0x18. C - Stacks, Queues - LIFO, FIFO

Requirements:

• Allowed editors: vi, vim, emacs
• Files will be compiled on Ubuntu 14.04 LTS
• Programs will be compiled with gcc 4.8.4 using -Wall -Werror -Wextra and -pedantic
• Files should end with a new line
• A README.md file, at the root of the folder of the project
• A code should use the Betty style. It will be checked using betty-style.pl and betty-doc.pl
• One global variable maximum
• No more than 5 functions per file
• C standard library
• The prototypes of all functions should be included in header file called monty.h
• All header files should be include guarded
• Do the tasks in the order shown in the project
• The repository monty should be added as a submodule to holbertonschool-low_level_programming repository, under the name 0x17-stacks_queues_lifo_fifo
• Use the following data structures for this project:

/**
 * struct stack_s - doubly linked list representation of a stack (or queue)
 * @n: integer
 * @prev: points to the previous element of the stack (or queue)
 * @next: points to the next element of the stack (or queue)
 *
 * Description: doubly linked list node structure
 * for stack, queues, LIFO, FIFO Holberton project
 */
typedef struct stack_s
{
        int n;
        struct stack_s *prev;
        struct stack_s *next;
} stack_t;

/**
 * struct instruction_s - opcode and its function
 * @opcode: the opcode
 * @f: function to handle the opcode
 *
 * Description: opcode and its function
 * for stack, queues, LIFO, FIFO Holberton project
 */
typedef struct instruction_s
{
        char *opcode;
        void (*f)(stack_t **stack, unsigned int line_number);
} instruction_t;

Compilation

$ gcc -Wall -Werror -Wextra -pedantic *.c -o monty

The Monty language

Monty 0.98 is a scripting language that is first compiled into Monty byte codes (Just like Python). It relies on a unique stack, with specific instructions to manipulate it. The goal of this project is to create an interpreter for Monty ByteCodes files.

Tasks

0. push, pall

Implement the push and pall opcodes.

Monty byte code files

Files containing Monty byte codes usually have the .m extension. Most of the industry uses this standard but it is not required by the specification of the language. There is not more than one instruction per line. There can be any number of spaces before or after the opcode and its argument:

julien@ubuntu:~/0x18. Stack (LIFO) & queue (FIFO)$ cat -e bytecodes/000.m
push 0$
push 1$
push 2$
  push 3$
                   pall    $
push 4$
    push 5    $
      push    6        $
pall$
julien@ubuntu:~/0x18. Stack (LIFO) & queue (FIFO)$

Monty byte code files can contain blank lines (empty or made of spaces only, and any additional text after the opcode or its required argument is not taken into account:

julien@ubuntu:~/0x18. Stack (LIFO) & queue (FIFO)$ cat -e bytecodes/001.m
push 0 Push 0 onto the stack$
push 1 Push 1 onto the stack$
$
push 2$
  push 3$
                   pall    $
$
$
                           $
push 4$
$
    push 5    $
      push    6        $
$
pall This is the end of our program. Monty is awesome!$
julien@ubuntu:~/0x18. Stack (LIFO) & queue (FIFO)$

The monty program

1. Usage: monty file
   • where file is the path to the file containing Monty byte code
2. If the user does not give any file or more than one argument to your program, print USAGE: monty file, followed by a new line, and exit with the status EXIT_FAILURE
3. If, for any reason, it’s not possible to use read the file, print Error: Can't open file , followed by a new line, and exit with the status EXIT_FAILURE
4. If the file contains an invalid instruction, print L<line_number>: unknown instruction <opcode>, followed by a new line, and exit with the status EXIT_FAILURE
   • Line numbers always start at 1
5. The monty program runs the bytecodes line by line and stop if:
   • it executed properly every line of the file
   • or it finds an error in the file
   • or an error occured
6. If you can’t malloc anymore, print Error: malloc failed, followed by a new line, and exit with status EXIT_FAILURE. You have to use malloc and free and are not allowed to use any other function from man malloc
7. All error messages must be printed on stdout

The push opcode

The opcode push pushes an element to the stack.

1. Usage: push <int>`` * where ` is an integer
2. If <int> is not an integer or if there is no argument to push, print the message L<line_number>: usage: push integer, followed by a new line, and exit with the status EXIT_FAILURE
3. You don’t have to deal with overflows. Use the atoi function

The pall opcode

The opcode pall prints all the values on the stack, starting from the top of the stack.

1. Usage: pall
2. Format: see example If the stack is empty, don’t print anything

julien@ubuntu:~/0x18. Stack (LIFO) & queue (FIFO)$ cat -e bytecodes/00.m
push 1$
push 2$
push 3$
pall$
julien@ubuntu:~/0x18. Stack (LIFO) & queue (FIFO)$ ./monty bytecodes/00.m
3
2
1
julien@ubuntu:~/0x18. Stack (LIFO) & queue (FIFO)$

The pint opcode

The opcode pint prints the value at the top of the stack, followed by a new line.

1. Usage: pint
2. If the stack is empty, print L<line_number>: can't pint, stack empty, followed by a new line, and exit with the status EXIT_FAILURE

julien@ubuntu:~/0x18. Stack (LIFO) & queue (FIFO)$ cat bytecodes/06.m
push 1
pint
push 2
pint
push 3
pint
julien@ubuntu:~/0x18. Stack (LIFO) & queue (FIFO)$ ./monty bytecodes/06.m
1
2
3
julien@ubuntu:~/0x18. Stack (LIFO) & queue (FIFO)$

The pop opcode

The opcode pop removes the top element of the stack.

1. Usage: pop
2. If the stack is empty, print L<line_number>: can't pop an empty stack, followed by a new line, and exit with the status EXIT_FAILURE

julien@ubuntu:~/0x18. Stack (LIFO) & queue (FIFO)$ cat bytecodes/07.m
push 1
push 2
push 3
pall
pop
pall
pop
pall
pop
pall
julien@ubuntu:~/0x18. Stack (LIFO) & queue (FIFO)$ ./monty bytecodes/07.m
3
2
1
2
1
1
julien@ubuntu:~/0x18. Stack (LIFO) & queue (FIFO)$

The swap opcode

The opcode swap swaps the top two elements of the stack.

1. Usage: swap
2. If the stack is less than two element long, print L<line_number>: can't swap, stack too short, followed by a new line, and exit with the status EXIT_FAILURE

julien@ubuntu:~/0x18. Stack (LIFO) & queue (FIFO)$ cat bytecodes/09.m
push 1
push 2
push 3
pall
swap
pall
julien@ubuntu:~/0x18. Stack (LIFO) & queue (FIFO)$ ./monty bytecodes/09.m
3
2
1
2
3
1
julien@ubuntu:~/0x18. Stack (LIFO) & queue (FIFO)$

The add opcode

The opcode add adds the top two elements of the stack.

1. Usage: add
2. If the stack is less than two element long, print L<line_number>: can't add, stack too short, followed by a new line, and exit with the status EXIT_FAILURE
3. The result is stored in the second top element of the stack, and the top element is removed, so that at the end: * the top element of the stack contains the result * the stack is one element shorter

julien@ubuntu:~/0x18. Stack (LIFO) & queue (FIFO)$ cat bytecodes/12.m
push 1
push 2
push 3
pall
add
pall

julien@ubuntu:~/0x18. Stack (LIFO) & queue (FIFO)$ ./monty bytecodes/12.m
3
2
1
5
1
julien@ubuntu:~/0x18. Stack (LIFO) & queue (FIFO)$

The nop opcode

The opcode nop doesn’t do anything :)

1. Usage: nop

The sub opcode

The opcode sub subtracts the top element of the stack from the second top element of the stack.

1. Usage: sub
2. If the stack is less than two element long, print L<line_number>: can't sub, stack too short, followed by a new line, and exit with the status EXIT_FAILURE
3. The result is stored in the second top element of the stack, and the top element is removed, so that at the end: * the top element of the stack contains the result * the stack is one element shorter

julien@ubuntu:~/0x18. Stack (LIFO) & queue (FIFO)$ cat bytecodes/19.m
push 1
push 2
push 10
push 3
sub
pall
julien@ubuntu:~/0x18. Stack (LIFO) & queue (FIFO)$ ./monty bytecodes/19.m
7
2
1
julien@ubuntu:~/0x18. Stack (LIFO) & queue (FIFO)$

The div opcode

The opcode div divides the second top element of the stack by the top element of the stack.

Usage: div If the stack is less than two element long, print L<line_number>: can't div, stack too short, followed by a new line, and exit with the status EXIT_FAILURE The result is stored in the second top element of the stack, and the top element is removed, so that at the end: the top element of the stack contains the result the stack is one element shorter If the top element of the stack is 0, print L<line_number>: division by zero, followed by a new line, and exit with the status EXIT_FAILURE

The mul opcode

The opcode mul multiplies the second top element of the stack with the top element of the stack.

Usage: mul If the stack is less than two element long, print L<line_number>: can't mul, stack too short, followed by a new line, and exit with the status EXIT_FAILURE The result is stored in the second top element of the stack, and the top element is removed, so that at the end: the top element of the stack contains the result the stack is one element shorter Repo:

GitHub repository: monty

The mod opcode

The opcode mod computes the rest of the division of the second top element of the stack by the top element of the stack.

Usage: mod If the stack is less than two element long, print L<line_number>: can't mod, stack too short, followed by a new line, and exit with the status EXIT_FAILURE The result is stored in the second top element of the stack, and the top element is removed, so that at the end: the top element of the stack contains the result the stack is one element shorter If the top element of the stack is 0, print L<line_number>: division by zero, followed by a new line, and exit with the status EXIT_FAILURE

10. comments

Every good language comes with the capability of commenting. When the first non-space character of a line is #, treat this line as a comment (don’t do anything).

The pchar opcode

The opcode pchar prints the char at the top of the stack, followed by a new line.

Usage: pchar The integer stored at the top of the stack is treated as the ascii value of the character to be printed If the value is not in the ascii table (man ascii) print L<line_number>: can't pchar, value out of range, followed by a new line, and exit with the status EXIT_FAILURE If the stack is empty, print L<line_number>: can't pchar, stack empty, followed by a new line, and exit with the status EXIT_FAILURE

julien@ubuntu:~/0x18. Stack (LIFO) & queue (FIFO)$ cat bytecodes/28.m
push 72
pchar
julien@ubuntu:~/0x18. Stack (LIFO) & queue (FIFO)$ ./monty bytecodes/28.m
H
julien@ubuntu:~/0x18. Stack (LIFO) & queue (FIFO)$

The pstr opcode

The opcode pstr prints the string starting at the top of the stack, followed by a new line.

Usage: pstr The integer stored in each element of the stack is treated as the ascii value of the character to be printed The string stops where: the stack is over the value of the element is 0 the value of the element is not in the ascii table If the stack is empty, print only a new line

julien@ubuntu:~/0x18. Stack (LIFO) & queue (FIFO)$ cat bytecodes/31.m
push 1
push 2
push 3
push 4
push 0
push 110
push 0
push 110
push 111
push 116
push 114
push 101
push 98
push 108
push 111
push 72
pstr
julien@ubuntu:~/0x18. Stack (LIFO) & queue (FIFO)$ ./monty bytecodes/31.m
Holberton
julien@ubuntu:~/0x18. Stack (LIFO) & queue (FIFO)$

The rotl opcode

The opcode rotl rotates the stack to the top.

Usage: rotl The top element of the stack becomes the last one, and the second top element of the stack becomes the first one rotl never fails

julien@ubuntu:~/0x18. Stack (LIFO) & queue (FIFO)$ cat bytecodes/35.m
push 1
push 2
push 3
push 4
push 5
push 6
push 7
push 8
push 9
push 0
pall
rotl
pall
julien@ubuntu:~/0x18. Stack (LIFO) & queue (FIFO)$ ./monty bytecodes/35.m
0
9
8
7
6
5
4
3
2
1
9
8
7
6
5
4
3
2
1
0
julien@ubuntu:~/0x18. Stack (LIFO) & queue (FIFO)$

The rotr opcode

The opcode rotr rotates the stack to the bottom.

Usage: rotr The last element of the stack becomes the top element of the stack rotr never fails

The stack opcode

The opcode stack sets the format of the data to a stack (LIFO). This is the default behavior of the program.

Usage: stack

The queue opcode

The opcode queue sets the format of the data to a queue (FIFO).

Usage: queue When switching mode:

the top of the stack becomes the front of the queue the front of the queue becomes the top of the stack

julien@ubuntu:~/0x18. Stack (LIFO) & queue (FIFO)$ cat bytecodes/47.m
queue
push 1
push 2
push 3
pall
stack
push 4
push 5
push 6
pall
add
pall
queue
push 11111
add
pall
julien@ubuntu:~/0x18. Stack (LIFO) & queue (FIFO)$ ./monty bytecodes/47.m
1
2
3
6
5
4
1
2
3
11
4
1
2
3
15
1
2
3
11111
julien@ubuntu:~/0x18. Stack (LIFO) & queue (FIFO)$

Brainf*ck

1. Write a Brainf*ck script that prints Holberton, followed by a new line.

All your Brainf*ck files should be stored inside the brainfuck sub directory You can install the bf interpreter to test your code: sudo apt-get install bf Read: Brainf*ck

julien@ubuntu:~/brainfuck$ bf 1000-holberton.bf
Holberton
julien@ubuntu:~/brainfuck$

2. Add two digits given by the user.

Read the two digits from stdin, add them, and print the result The total of the two digits with be one digit-long (<10)

julien@ubuntu:~/brainfuck$ bf ./1001-add.bf
81
9julien@ubuntu:~/brainfuck$