Project: Node Manager $-$ C Program Shell Implementation

Overview:

$-$ Create a C program that acts as a basic shell named Node Manager.

$-$ Reinforces linked lists, string handling, bitwise operations, and managing multiple source files.

Files and Directory Structure:

$-`$p$3\_$handout$`$ Directory contains:

$-`$src$/$nodemngr$.$c$`$: The source file you need to modify.

$-`$inc$/$listnode$.$h$`$: Contains the ListNode structure.

$-`$inc$/$exec$.$h$`$: Contains function prototypes.

$-`$obj$/$exec$.$o$`$: Object file for linking during compilation.

$-`$inputs$/`$ and $`$outputs$/`$: Test case directories used with the testing script.

$-`$Makefile$`$: Used for compiling the project.

$-`$driver$.$py$`$: Python script to test the shell.

$-$ Text files $(`$joestar$.$txt$`,`$kakyoin$.$txt$`,`$avdol$.$txt$`)$: Provided for testing with List Nodes.

Shell Requirements:

$-**$Command Prompt and Input Loop$**$:

$-$ Shell prompt: $`262$$$`.$

$-$ Print prompt using $`$fflush$($stdout$)$;$`.$

$-$ Continuously loop until EOF is detected.

$-**$Command Parsing and Execution$**$:

$-$ Parse input commands using whitespace as the delimiter.

$-$ Commands can have multiple arguments, with input size limited to $**10,000$ characters$**.$

Built$-$in Commands:

$1.**`$quit$`**$: Exits the shell, deallocates resources, no arguments.

$2.**`$cd $[$dir$]`**$: Changes current directory using $`$chdir$`.$ Prints errors for invalid directory or incorrect arguments.

$3.**`$history$`**$: Displays$/$manages history of the last $**100$ commands$**.$

$-**`$history $-$c$`**$: Clears command history.

$-**`$history $[$index$]`**$: Re$-$executes a command from history by index.

$4.**`$new CMD $[$args$]`**$: Creates a new List Node with a command and arguments.

$-$ A List Node includes: command, arguments, and other details.

$5.**`$list$`**$: Displays information about all current List Nodes.

$6.**`$open $[$id$][$filename$]`**$: Opens a file and assigns its contents to the List Node by ID$.$

$-$ Handles errors for invalid IDs, missing files, and incorrect arguments.

$7.**`$execute $[$id$]`**$: Executes the command stored in a List Node by calling $`$run$\_$command$()`.$

$-$ Extracts exit status and reports errors if unsuccessful.

$-$ Commands are limited to $**127$ arguments$**.$

Key Implementation Requirements:

$-**$No Global Variables$**$: Only local variables are allowed.

$-**$Memory Management$**$: Proper deallocation of resources $($must pass Valgrind with no memory leaks$).$

$-**$Command History$**$: Manages up to $**100$ commands$**,$ replacing the oldest entry when full.

ListNode Structure $($from $`$listnode$.$h$`)$:

$```$c

typedef struct ListNode $\{$

char $*$command; $//$ Command associated with the node

char $**$arguments; $//$ Array of argument strings $($command is arguments$[0])$

struct ListNode $*$next; $//$ Pointer to the next List Node

int id; $//$ ID of the List Node $($starts from $0)$

int arguments$\_$length; $//$ Number of arguments excluding ending NULL pointer

char $*$file$\_$contents; $//$ Contents of any file opened for this node

$\}$ ListNode;

$```$

Testing and Submission Instructions:

$1.**$Testing$**$:

$-$ Use the provided $`$Makefile$`$ to compile the project.

$-$ Run $**`$driver$.$py$`**$ to test with provided test cases.

$-$ Example output from $**`$driver$.$py$`**$ awards scores based on functionality and memory safety.

Driver Script $(`$driver$.$py$`)$ Scoring:

$-$ Scores range from $**0$ to $2**$:

$-**0**$: Compilation failure or incorrect output with memory leaks.

$-**1**$: Correct output but with memory leaks.

$-**2**$: Correct output and no memory leaks.