lab08.md

Lab 8

In this lab, you will expose the functionality of Lab 6 both as an interpreter and as an interactive debugger for the byte command language of Lab 2.

Note: Unlike Lab 6, you are welcome to use the solutions posted for previous labs at no penalty.

Your program should accept any number of command line arguments. Each argument should be the name of a file containing byte instructions. Execute these instructions in order, and print the value of the byte at the end.

Use the C Standard File I/O functions from <stdio.h> to read each file.

In addition to the command-line arguments, your program should also accept the following command-line options:

Option	Meaning
-v	verbose - print each byte command and its result
-d	debug - Accept debug commands from standard input

Use getopt() to parse the command-line options, as described in Chapter 2 of UNIX Systems Programming for SVR4.

Note: In order to use getopt() you will need to:

1. Include <unistd.h>
2. Modify CFLAGS to include -D_POSIX_C_SOURCE=200801L

Examples

$ ./calculator lab02.input 
e

$ cat > extra.input <<EOF
> set 42
> EOF

$ ./calculator lab02.input extra.input
42

$ ./calculator -v lab02.input extra.input
set 1 => 1
shl 1 => 2
shl 1 => 4
or 1 => 5
or 2 => 7
shl 2 => 1c
xor 10 => c
xor 10 => 1c
and 4 => 4
set 1c => 1c
and 3 => 0
set 1c => 1c
shr 1 => e
set 42 => 42

$ ./calculator -d lab02.input extra.input
list
 1 set 1
 2 shl 1
continue
list
13 shr 1
14 set 42
quit

$ ./calculator -d -v lab02.input extra.input
list
 1 set 1
 2 shl 1
step
set 1 => 1
list
 1 set 1
 2 shl 1
 3 shl 1
continue
shl 1 => 2
shl 1 => 4
or 1 => 5
or 2 => 7
shl 2 => 1c
xor 10 => c
xor 10 => 1c
and 4 => 4
set 1c => 1c
and 3 => 0
set 1c => 1c
shr 1 => e
set 42 => 42
quit