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Meeting Summary for CS 326 Lecture/Lab Spring 2025

Date & Time: February 05, 2025, 06:28 PM Pacific Time (US & Canada)
Meeting ID: 813 3845 7711

Quick Recap

During the session, Greg provided updates on Lab 2, focusing on assignment requirements and auto-grading procedures. The lecture included:

  • Lab 2 Updates
    • New requirements and updates for the assignment.
    • Integration of a Google Sheet for collecting GitHub IDs for auto-grading.
  • Code Formatting & Tools
    • Introduction to Markdown for lab questions and AI code assist.
    • Demonstration of the uncrustify utility for enforcing code style.
    • Guidance on configuring Visual Studio Code for automatic formatting.
  • General Guidance
    • Emphasis on code quality and systematic approaches when tackling coding tasks.
    • Discussion on file comparison techniques and clarifications on project deadlines.

Next Steps

The following action items were proposed:

  • Greg’s Actions:
    • Update the uncrustify configuration file to improve code formatting consistency.
    • Post instructions for using uncrustify on the course website.
    • Create and share a Google Sheet for students to submit their GitHub IDs.
    • Work with Phil to update the auto-grader to accept two versions of the cat -n implementation.
    • Upload a Markdown template for exam questions on Campus Wire.
    • Investigate integration of uncrustify with the micro editor.
    • Provide additional C programming resources along with an interactive learning tool on the course website.
    • Update Lab 2 to optionally allow restarting the line count for each new file in the cat -n implementation.
  • Students’ Actions:
    • Practice using uncrustify for code formatting in lab assignments.
    • Follow coding assistant guidelines when using AI tools for assignment help.

Detailed Summary

Lab 2 Updates and Assignment Requirements

Greg confirmed that Lab 2 has been updated. Key points include:

  • Assignment Components:
    • GitHub IDs: A Google Sheet will be circulated for auto-grading purposes.
    • Gen File Component:
      • Offers hands-on experience with writing system calls.
      • Provides test files for verifying the diff command.
      • Specifies the expected output format for file differences.
  • Task Complexity:
    • The sort task is acknowledged as more challenging than the diff task.
  • Coding Guidelines:
    • Questions regarding coding style were addressed, and resource updates are planned accordingly.

xv6-riscv Example: A Simplified cat -n Implementation

Below is a basic xv6-riscv C code snippet that illustrates a possible approach for numbering lines in a file:

// cat -n: Print file contents with line numbers.
#include "types.h"
#include "stat.h"
#include "user.h"
#include "fcntl.h"

int main(int argc, char *argv[]) {
  int fd, line = 1;
  char buf[512];

  if(argc < 2) {
    printf(2, "Usage: cat -n filename ...\n");
    exit();
  }

  for (int i = 1; i < argc; i++) {
    fd = open(argv[i], O_RDONLY);
    if(fd < 0) {
      printf(2, "cat: cannot open %s\n", argv[i]);
      continue;
    }
    int n;
    while((n = read(fd, buf, sizeof(buf))) > 0) {
      /* Here, one would typically parse buf to print each line with its number. */
      printf(1, "%d: %s", line++, buf);
    }
    close(fd);
  }
  exit();
}

Markdown and Code Formatting Tools

Greg explained the use of Markdown for creating well-structured lab questions and provided an overview of the code formatting utility uncrustify. Key points include:

  • Markdown:
    • A lightweight markup language ideal for formatting text, including headings, quotes, lists, and code blocks.
    • Widely used by language models and supported by many editors for clear content structuring.
  • Uncrustify:
    • A customizable tool that enforces coding style conventions.
    • Can be configured via dedicated configuration files.
    • Integration options include command line usage, a Visual Studio Code extension, and even potential usage with the micro editor.

Uncrustify Tool Demonstration and Usage

Key steps in using uncrustify include:

  • Usage Modes:
    • Command Line: Running uncrustify directly from a terminal.
    • Visual Studio Code Extension: Automatically applying formatting on file save.
  • Setup Considerations:
    • Environment variables and proper configuration file setup.
    • Creating backups and redirecting output to avoid losing original content.

xv6-riscv Example Shell Script for Automatic Formatting

This shell script demonstrates how uncrustify can be used to format all C source files in a directory:

#!/bin/bash
# Backup and format all .c files in the current directory.
for file in *.c; do
    cp "$file" "$file.bak"
    uncrustify -c uncrustify.cfg "$file" > "$file.formatted"
    mv "$file.formatted" "$file"
done

Mermaid Diagram: Uncrustify Formatting Workflow

flowchart TD
    A[User edits source file in VS Code] --> B[File Save triggers auto-format]
    B --> C[VS Code extension calls uncrustify]
    C --> D[uncrustify processes file using configuration]
    D --> E[Formatted file is saved]

Automatic File Formatting Process

Greg discussed setting up an automatic formatting process by placing a configuration file at the repository root. This allows for:

  • Automatic Formatting in Visual Studio Code:
    • The use of extensions to reformat files automatically on save.
  • Optional Shell Script:
    • A script to selectively reformat files based on whether they differ from the desired style.
    • Caution against wholesale changes to every file.

Code Quality and Assistance Guidelines

Key points emphasized by Greg include:

  • Maintaining Code Quality:
    • Consistent formatting and proper commenting are crucial.
    • Code quality feedback will be provided on projects.
  • Guidelines for Using Coding Assistants:
    • Students should first attempt problems on their own.
    • Use AI or coding assistants only after thorough review of relevant material and code.
    • Engage with generated solutions—ask questions and consider refactoring if needed.
    • Seek help for environment setup or other technical challenges as required.

Technical Issues and Coding Solutions

Greg addressed several technical challenges encountered during development, including:

  • Configuration and Environment Issues:
    • Problems with configuration files and interactive tool features.
    • Solutions for integrating various tools and extensions.
  • Miscellaneous Topics:
    • Brief mentions of personal habits and lifestyle, which were tangential to the main technical discussions.

File Comparison Techniques and Deadlines

The session also covered techniques for file comparison and outlined deadlines:

  • File Comparison Process:
    • Open two files simultaneously.
    • Read lines from each file and compare them using string comparison functions.
    • Use pointers to iterate through file contents.
  • Project Deadlines:
    • Discussion of upcoming project deadlines.
    • Plans for the next meeting were mentioned, with Greg noting availability for the following Wednesday.

Mermaid Diagram: File Comparison Process

flowchart TD
    A[Start File Comparison] --> B[Open File1 and File2]
    B --> C[Read a line from each file]
    C --> D{Are the lines equal?}
    D -- Yes --> C
    D -- No --> E[Record difference]
    E --> C
    C --> F[End of file reached?]
    F -- Yes --> G[Finish comparison]

This summary provides a clear and organized review of the session, highlighting key actions, technical demonstrations, and future tasks. The integration of code examples and diagrams helps concretize the concepts discussed during the meeting.

References