Stories with Tag network

• Bcvi – run vi over a 'back-channel' (2010)

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  Posted: 2025-03-06 18:55:47

  Verbose tl;dr

  Bcvi allows running a full-screen vi editor session over a limited bandwidth or high-latency connection, such as a serial console or SSH connection with significant lag. It achieves this by using a "back-channel" to send screen updates efficiently. Instead of redrawing the entire screen for every change, bcvi only transmits the differences, leading to a significantly more responsive experience. This makes editing files remotely over constrained connections practical, providing a near-native vi experience even with limited bandwidth. The back-channel can be another SSH connection or even a separate serial port, providing flexibility in setup.

  The article "bcvi – run vi over a 'back-channel'" describes a novel approach to editing files remotely over a constrained network connection, specifically targeting situations where using tools like SSH or VNC might be impractical due to bandwidth limitations or latency issues. The core concept revolves around establishing a "back-channel" which is a separate, lower-bandwidth communication pathway alongside the primary channel being used for other purposes. This back-channel is then leveraged by a custom-designed program called bcvi to facilitate remote file editing using the familiar Vi editor interface.

  The article details the technical implementation of bcvi, explaining how it functions as a proxy between the user's local Vi instance and the remote file. Instead of transmitting the entire screen or file content back and forth, bcvi only exchanges minimal information necessary for Vi's operation. This includes keystrokes entered by the user, cursor movements, and changes to the file's buffer. The program achieves this efficiency by hooking into Vi's internal functions to intercept and process these events. On the remote end, a corresponding component of bcvi interprets the transmitted commands and applies them to the target file. The resulting changes are then relayed back to the local Vi instance, updating the user's view accordingly.

  The back-channel communication itself is handled through a separate program called bc, which utilizes User Datagram Protocol (UDP) for its transport. This choice is motivated by the desire to minimize overhead and tolerate occasional packet loss, making it suitable for unreliable network conditions. The bc program encapsulates the Vi-specific commands and data within UDP packets, ensuring efficient and robust transmission over the back-channel.

  The article highlights several advantages of using bcvi. The reduced bandwidth consumption makes it ideal for slow or intermittent connections. The responsiveness, despite potentially high latency, is attributed to the asynchronous nature of the communication. The familiarity of the Vi interface offers a comfortable and efficient editing experience for users already accustomed to Vi's commands and workflows. The article further emphasizes the portability of bcvi, stating its compatibility with various Unix-like systems and its reliance on readily available tools like Vi and UDP.

  Finally, the article discusses the potential use cases for bcvi, such as editing configuration files on embedded devices or managing files on remote servers with limited connectivity. It also touches upon the inherent limitations of the approach, acknowledging the potential impact of significant packet loss on the editing experience and the assumption that the remote system has a compatible version of Vi installed. The overall tone suggests that bcvi offers a practical and efficient solution for remote file editing in specific, constrained environments.

  • vi
  • vim
  • Text Editor
  • command-line
  • terminal
  • remote editing
  • back-channel
  • ssh
  • network
  • bcvi
  • 2010
  • unix
  • Linux
  • Software
  • Tool

  Summary of Comments ( 13 )
  https://news.ycombinator.com/item?id=43283814

  Verbose tl;dr

  Hacker News users discuss the cleverness and potential uses of bcvi, particularly for embedded systems debugging. Some express admiration for the ingenuity of using the back channel for editing, highlighting its usefulness when other methods are unavailable. Others question the practicality due to potential slowness and limitations, suggesting alternatives like ed. A few commenters reminisce about using similar techniques in the past, emphasizing the historical context of this approach within resource-constrained environments. Some discuss potential security implications, pointing out that the back channel could be vulnerable to manipulation. Overall, the comments appreciate the technical ingenuity while acknowledging the niche appeal of bcvi.

  The Hacker News post "Bcvi – run vi over a 'back-channel' (2010)" has several comments discussing the utility and implications of the bcvi tool.

  One commenter highlights the potential security risks of using such a tool, especially if the back channel isn't adequately secured. They express concern about inadvertently exposing sensitive information or granting unintended access to a system. This concern is echoed by another user who points out the inherent danger of trusting arbitrary escape sequences. They suggest that, while interesting, the approach presents a significant attack surface.

  Another commenter questions the practical applications of bcvi, wondering in what scenarios it would be genuinely useful. They acknowledge the cleverness of the concept but struggle to envision situations where it would be preferable to established methods of remote file editing. This skepticism is shared by a separate commenter who points out the existing availability of tools like sshfs which offer a more robust and secure way to edit remote files.

  Several commenters delve into the technical aspects of bcvi, discussing its implementation and potential limitations. One points out the challenge of handling interactive commands and the need for careful consideration of terminal emulation. Another user mentions the project's age and expresses curiosity about its current status and whether it's still actively maintained.

  A commenter recalls using a similar technique in the past, involving screen and vi, for editing files over a serial console. They describe the setup and the advantages it offered in their specific use case. This anecdote provides a practical example of a scenario where a back-channel editing approach could be beneficial.

  One commenter humorously suggests using netcat as a more straightforward alternative for editing remote files over a simple connection. While likely intended as a tongue-in-cheek suggestion, it highlights the potential simplicity of achieving similar functionality with readily available tools.

  Finally, a few comments express general appreciation for the cleverness and ingenuity of the bcvi concept, even if its practicality is debated. They acknowledge the value of exploring unconventional approaches to problem-solving.

• Stats – macOS system monitor in your menu bar

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  Posted: 2025-01-30 19:37:42

  Verbose tl;dr

  Stats is a free and open-source macOS menu bar application that provides a comprehensive overview of system performance. It displays real-time information on CPU usage, memory, network activity, disk usage, battery health, and fan speeds, all within a customizable and compact menu bar interface. Users can tailor the displayed modules and their appearance to suit their needs, choosing from various graph styles and refresh rates. Stats aims to be a lightweight yet powerful alternative to larger system monitoring tools.

  The GitHub repository, stats by user exelban, introduces a macOS application that provides real-time system monitoring directly within the menu bar. This application offers a compact and readily accessible overview of vital system statistics, eliminating the need to open larger, more resource-intensive applications like Activity Monitor. The displayed information is highly configurable, allowing users to customize which metrics are visible and how they are presented.

  Among the available metrics are CPU usage, broken down by individual core utilization and overall system load; memory usage, including details on used, wired, compressed, and cached memory; disk activity, displaying read and write speeds for connected drives; network activity, showing upload and download speeds for active network interfaces; battery status, providing information on current charge level and time remaining; and sensor data, encompassing temperatures and fan speeds for various system components.

  stats offers a high degree of visual customization. Users can select from various pre-built themes or create their own, tailoring the appearance of the menu bar display to match their preferences or system aesthetics. The level of detail shown can also be adjusted, allowing users to choose between concise summaries and more comprehensive breakdowns of system resource usage. This flexibility makes stats adaptable to different user needs and workflows.

  The application is built using Swift and leverages native macOS APIs, potentially leading to efficient performance and seamless integration with the operating system. The project is open-source and hosted on GitHub, enabling community contributions and further development. The readily available source code allows for transparency and potential customization beyond the provided configuration options. While offering a comprehensive suite of features out-of-the-box, the open-source nature suggests the possibility of extending its functionality further based on user needs and community input.

  • macOS
  • system monitor
  • menu bar
  • utility
  • performance monitoring
  • resource usage
  • CPU
  • Memory
  • disk
  • network
  • Open Source
  • GitHub
  • Stats

  Summary of Comments ( 5 )
  https://news.ycombinator.com/item?id=42881342

  Verbose tl;dr

  Hacker News users generally praised Stats' minimalist design and useful information display in the menu bar. Some suggested improvements, including customizable refresh rates, more detailed CPU information (like per-core usage), and GPU temperature monitoring for M1 Macs. Others questioned the need for another system monitor given existing options, with some pointing to iStat Menus as a more mature alternative. The developer responded to several comments, acknowledging the suggestions and clarifying current limitations and future plans. Some users appreciated the open-source nature of the project and the developer's responsiveness. There was also a minor discussion around the chosen license (GPLv3).

  The Hacker News post for "Stats – macOS system monitor in your menu bar" (https://news.ycombinator.com/item?id=42881342) has a moderate number of comments discussing various aspects of the application and system monitoring tools in general.

  Several commenters praise Stats' clean design and comprehensive feature set, contrasting it favorably to other menu bar monitors. One user appreciates its ability to display network speeds directly in the menu bar, a feature they find particularly useful. Others highlight the detailed graphs and customization options available within the app.

  A recurring theme in the comments is the discussion of alternative system monitoring tools. Some users mention iStat Menus as a long-time favorite, while others suggest BitBar and MenuMeters as viable free alternatives. The comparison often revolves around the balance between features, performance impact, and cost, with some users expressing concerns about Stats' potential resource usage compared to simpler solutions.

  The developer of Stats actively participates in the comment section, addressing user questions and feedback. They clarify licensing details, explain the rationale behind certain design choices, and acknowledge areas for potential improvement, like optimizing CPU usage. This direct engagement with the community is seen positively by several commenters.

  A few users raise concerns about the privacy implications of running third-party monitoring tools, particularly those that require elevated permissions. This sparks a brief discussion about the trade-offs between functionality and privacy.

  One commenter points out the challenge of achieving a truly lightweight system monitor, suggesting that the desire for comprehensive data inevitably leads to increased resource consumption. This comment highlights the inherent tension between feature richness and performance optimization in this type of software.

  Finally, there are some specific technical queries and suggestions related to features like GPU monitoring and network interface selection. These comments provide valuable feedback for the developer and contribute to a discussion about the specific needs of users in different contexts.