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.
Compilation Your code will be compiled this way: $ gcc -Wall -Werror -Wextra -pedantic *.c -o monty Any output will be printed on stdout. Any error message will be printed on stderr. 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:
bryanekong@ubuntu:/0x18-stacks_queues_lifo_fifo$ cat -e bytecodes/000.m
push 0$
push 1$
push 2$
push 3$
pall $
push 4$
push 5 $
push 6 $
pall$
bryanekong@ubuntu:/0x18-stacks_queues_lifo_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:
bryanekong@ubuntu:/0x18-stacks_queues_lifo_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!$
bryanekong@ubuntu:/0x18-stacks_queues_lifo_fifo$
The monty program
Usage: monty file
where file is the path to the file containing Monty byte code.
If the user does not give any file or more than one argument to your program, print the error message USAGE: monty file, followed by a new line, and exit with the status EXIT_FAILURE.
If, for any reason, it’s not possible to open the file, print the error message Error: Can't open file , followed by a new line, and exit with the status EXIT_FAILURE.
where is the name of the file.
If the file contains an invalid instruction, print the error message L<line_number>: unknown instruction , followed by a new line, and exit with the status EXIT_FAILURE.
where <line_number> the line number where the instruction appears.
Line numbers always start at 1.
The monty program runs the bytecodes line by line and stop if either:
it executed properly every line of the file.
it finds an error in the file.
an error occured.
If you can’t malloc anymore, print the error message Error: malloc failed, followed by a new line, and exit with status EXIT_FAILURE.
Output
Here are some examples of the output for th opcodes used.
The push opcode - The opcode push pushes an element to the stack.
Usage: push . where is an integer. The pall opcode
The opcode pall prints all the values on the stack, starting from the top of the stack.
Usage pall.
Format: see example.
If the stack is empty, don’t print anything.
bryanekong@ubuntu:/0x18-stacks_queues_lifo_fifo$ cat -e bytecodes/00.m
push 1$
push 2$
push 3$
pall$
bryanekong@ubuntu:/0x18-stacks_queues_lifo_fifo$ ./monty bytecodes/00.m
3
2
1
bryanekong@ubuntu:~/0x18-stacks_queues_lifo_fifo$
The add opcode - The opcode add adds the top two elements of the stack.
Usage: add 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. bryanekong@ubuntu:~/0x18-stacks_queues_lifo_fifo$ cat bytecodes/12.m push 1 push 2 push 3 pall add pall