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• A project done during my Full-Stack Software Engineering studies atALX Africa, a course offered byHolberton School.

• Files written invi,vim, andemacs editors.
• C files compiled usinggcc 9.4.0.
• C files wriiten according to the betty coding style. Checked usingbetty-style.pl andbetty-doc.pl.
• Files tested onUbuntu 20.04 LTS usinggcc.
• Outpus are printed onstdout
• Error messages printed onstderr

• 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.

• 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
• 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.

• Usage:monty file
  • where file is the path to the file containing Monty byte code.

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

$ ./monty monty_file.m5712

$ ./monty [montyfilename]$

• If the user does not give any file or more than one argument to your program, print the error messageUSAGE: monty file, followed by a new line, and exit with the statusEXIT_FAILURE
• If, for any reason, it’s not possible to open the file, print the error messageError: Can't open file <file>, followed by a new line, and exit with the statusEXIT_FAILURE.
  • where<file> is the name of the file.
• If the file contains an invalid instruction, print the error messageL<line_number>: unknown instruction <opcode>, followed by a new line, and exit with the statusEXIT_FAILURE
  • where is 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, the program prints the error messageError: malloc failed, followed by a new line, and exit with statusEXIT_FAILURE.

1. pint

• The opcodepint prints the value at the top of the stack, followed by a new line.

Usage:pint

• If the stack is empty, print the error messageL<line_number>: can't pint, stack empty, followed by a new line, and exit with the statusEXIT_FAILURE
• Example:

micahondiwa@ubuntu:~/monty$ cat bytecodes/06.m push 1pintpush 2pintpush 3pintmicahondiwa@ubuntu:~/monty$ ./monty bytecodes/06.m 123micahondiwa@ubuntu:~/monty$

2. pop

• The opcodepop removes the top element of the stack.

Usage:pop

• If the stack is empty, print the error messageL<line_number>: can't pop an empty stack, followed by a new line, and exit with the statusEXIT_FAILURE
• Example:

micahondiwa@ubuntu:~/monty$ cat bytecodes/07.m push 1push 2push 3pallpoppallpoppallpoppallmicahondiwa@ubuntu:~/monty$ ./monty bytecodes/07.m 321211micahondiwa@ubuntu:~/monty$

3. swap

• The opcodeswap swaps the top two elements of the stack.

Usage:swap

• If the stack contains less than two elements, print the error messageL<line_number>: can't swap, stack too short, followed by a new line, and exit with the statusEXIT_FAILURE-Example:

micahondiwa@ubuntu:~/monty$ cat bytecodes/09.m push 1push 2push 3pallswappallmicahondiwa@ubuntu:~/monty$ ./monty bytecodes/09.m 321231micahondiwa@ubuntu:~/monty$

4. add

• The opcodeadd adds the top two elements of the stack.

Usage:add

• If the stack contains less than two elements, print the error messageL<line_number>: can't add, stack too short, followed by a new line, and exit with the statusEXIT_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

• Example:

micahondiwa@ubuntu:~/monty$ cat bytecodes/12.m push 1push 2push 3palladdpallmicahondiwa@ubuntu:~/monty$ ./monty bytecodes/12.m 3215micahondiwa@ubuntu:~/monty$

5. nop

• The opcodenop doesn’t do anything!

Usage:nop

6. sub

• The opcodesub subtracts the top element of the stack from the second top element of the stack.

Usage:sub

• If the stack contains less than two elements, print the error messageL<line_number>: can't sub, stack too short, followed by a new line, and exit with the statusEXIT_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
• Example:

micahondiwa@ubuntu:~/monty$ cat bytecodes/19.m push 1push 2push 10push 3subpallmicahondiwa@ubuntu:~/monty$ ./monty bytecodes/19.m 721

7. div

• The opcodediv divides the second top element of the stack by the top element of the stack.

Usage:div

• If the stack contains less than two elements, print the error messageL<line_number>: can't div, stack too short, followed by a new line, and exit with the statusEXIT_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 is0, print the error messageL<line_number>: division by zero, followed by a new line, and exit with the statusEXIT_FAILURE

8. mul

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

Usage:mul

• If the stack contains less than two elements, print the error messageL<line_number>: can't mul, stack too short, followed by a new line, and exit with the statusEXIT_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
  • nThe stack is one element shorter

9. mod

• The opcodemod 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 contains less than two elements, print the error messageL<line_number>: can't mod, stack too short, followed by a new line, and exit with the statusEXIT_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 the error message L<line_number>: division by zero, followed by a new line, and exit with the status EXIT_FAILURE

10. pchar

• The opcodepchar prints the char at the top of the stack.

• 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 the error messageL<line_number>: can't pchar, value out of range, followed by a new line, and exit with the statusEXIT_FAILURE

• If the stack is empty, print the error messageL<line_number>: can't pchar, stack empty, followed by a new line, and exit with the status EXIT_FAILURE

• Example:

micahondiwa@ubuntu:~/monty$ cat bytecodes/28.m push 72pcharmicahondiwa@ubuntu:~/monty$ ./monty bytecodes/28.m Hmicahondiwa@ubuntu:~/monty$

11. pstr

• The opcodepstr 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 when either:
  • 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
• Example:

micahondiwa@ubuntu:~/monty$ cat bytecodes/31.m push 1push 2push 3push 4push 0push 110push 0push 108push 111push 111push 104push 99push 83micahondiwa@ubuntu:~/monty$ ./monty bytecodes/31.m Schoolmicahondiwa@ubuntu:~/monty$

12. rotl

• The opcoderotl 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 onerotl never fails
• Example:

micahondiwa@ubuntu:~/monty$ cat bytecodes/35.m push 1push 2push 3push 4push 5push 6push 7push 8push 9push 0pallrotlpallmicahondiwa@ubuntu:~/monty$ ./monty bytecodes/35.m 09876543219876543210micahondiwa@ubuntu:~/monty$

13. rotr

• The opcoderotr rotates the stack to the bottom.

Usage: rotr

• The last element of the stack becomes the top element of the stackrotr never fails

14. stack,queue

The stack opcode

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

• Usage: ```stack``

The queue opcode

• The opcodequeue 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

-Example:

micahondiwa@ubuntu:~/monty$ cat bytecodes/47.mqueuepush 1push 2push 3pallstackpush 4push 5push 6palladdpallqueuepush 11111addpallmicahondiwa@ubuntu:~/monty$ ./monty bytecodes/47.m1236541231141231512311111micahondiwa@ubuntu:~/monty$

Author:micahondiwa