Fedora is implementing a change to enhance package reproducibility, aiming for a 99% success rate. This involves using "source date epochs" (SDE) which fixes build timestamps to a specific point in the past, eliminating variations caused by differing build times. While this approach simplifies reproducibility checks and reduces false positives, it won't address all issues, such as non-deterministic build processes within the software itself. The project is actively seeking community involvement in testing and reporting any remaining non-reproducible packages after the SDE switch.
mem-isolate
is a Rust crate designed to execute potentially unsafe code within isolated memory compartments. It leverages Linux's memfd_create
system call to create anonymous memory mappings, allowing developers to run untrusted code within these confined regions, limiting the potential damage from vulnerabilities or exploits. This sandboxing approach helps mitigate security risks by restricting access to the main process's memory, effectively preventing malicious code from affecting the wider system. The crate offers a simple API for setting up and managing these isolated execution environments, providing a more secure way to interact with external or potentially compromised code.
Hacker News users discussed the practicality and security implications of the mem-isolate
crate. Several commenters expressed skepticism about its ability to truly isolate unsafe code, particularly in complex scenarios involving system calls and shared resources. Concerns were raised about the performance overhead and the potential for subtle bugs in the isolation mechanism itself. The discussion also touched on the challenges of securely managing memory in Rust and the trade-offs between safety and performance. Some users suggested alternative approaches, such as using WebAssembly or language-level sandboxing. Overall, the comments reflected a cautious optimism about the project but acknowledged the difficulty of achieving complete isolation in a practical and efficient manner.
This book, "Introduction to System Programming in Linux," offers a practical, project-based approach to learning low-level Linux programming. It covers essential concepts like process management, memory allocation, inter-process communication (using pipes, message queues, and shared memory), file I/O, and multithreading. The book emphasizes hands-on learning through coding examples and projects, guiding readers in building their own mini-shell, a multithreaded web server, and a key-value store. It aims to provide a solid foundation for developing system software, embedded systems, and performance-sensitive applications on Linux.
Hacker News users discuss the value of the "Introduction to System Programming in Linux" book, particularly for beginners. Some commenters highlight the importance of Kay Robbins and Dave Robbins' previous work, expressing excitement for this new release. Others debate the book's relevance given the wealth of free online resources, although some counter that a well-structured book can be more valuable than scattered web tutorials. Several commenters express interest in seeing more practical examples and projects within the book, particularly those focusing on modern systems and real-world applications. Finally, there's a brief discussion about alternative learning resources, including the Linux Programming Interface and Beej's Guide.
Paged Out #6 explores the growing complexity in software, focusing on the challenges of debugging. It argues that traditional debugging methods are becoming inadequate for modern systems, which often involve distributed architectures, asynchronous operations, and numerous interacting components. The zine dives into various advanced debugging techniques like reverse debugging, using eBPF for observability, and applying chaos engineering principles to uncover vulnerabilities. It highlights the importance of understanding system behavior as a whole, rather than just individual components, advocating for tools and approaches that provide a more holistic view of execution flow and state. Finally, it touches on the psychological aspects of debugging, emphasizing the need for patience, persistence, and a structured approach to problem-solving in complex environments.
HN users generally praised the issue of Paged Out, finding the articles well-written and insightful. Several commenters highlighted specific pieces, such as the one on "The Spectre of Infinite Retry" and another discussing the challenges of building a database on top of a distributed consensus system. The article on the Unix philosophy also generated positive feedback. Some users appreciated the magazine's focus on systems programming and lower-level topics. There was some light discussion of the practicality of formal methods in software development, prompted by one of the articles. Overall, the reception was very positive with many expressing anticipation for future issues.
Google is shifting internal Android development to a private model, similar to how it develops other products. While Android will remain open source, the day-to-day development process will no longer be publicly visible. Google claims this change will improve efficiency and security. The company insists this won't affect the open-source nature of Android, promising continued AOSP releases and collaboration with external partners. They anticipate no changes to the public bug tracker, release schedules, or the overall openness of the platform itself.
Hacker News users largely expressed skepticism and concern over Google's shift towards internal Android development. Many questioned whether "open source releases" would truly remain open if Google's internal development diverged significantly, leading to a de facto closed-source model similar to iOS. Some worried about potential stagnation of the platform, with fewer external contributions and slower innovation. Others saw it as a natural progression for a maturing platform, focusing on stability and polish over rapid feature additions. A few commenters pointed out the potential benefits, such as improved security and consistency through tighter control. The prevailing sentiment, however, was cautious pessimism about the long-term implications for Android's openness and community involvement.
The blog post "Entropy Attacks" argues against blindly trusting entropy sources, particularly in cryptographic contexts. It emphasizes that measuring entropy based solely on observed outputs, like those from /dev/random
, is insufficient for security. An attacker might manipulate or partially control the supposedly random source, leading to predictable outputs despite seemingly high entropy. The post uses the example of an attacker influencing the timing of network packets to illustrate how seemingly unpredictable data can still be exploited. It concludes by advocating for robust key-derivation functions and avoiding reliance on potentially compromised entropy sources, suggesting deterministic random bit generators (DRBGs) seeded with a high-quality initial seed as a preferable alternative.
The Hacker News comments discuss the practicality and effectiveness of entropy-reduction attacks, particularly in the context of Bernstein's blog post. Some users debate the real-world impact, pointing out that while theoretically interesting, such attacks often rely on unrealistic assumptions like attackers having precise timing information or access to specific hardware. Others highlight the importance of considering these attacks when designing security systems, emphasizing defense-in-depth strategies. Several comments delve into the technical details of entropy estimation and the challenges of accurately measuring it. A few users also mention specific examples of vulnerabilities related to insufficient entropy, like Debian's OpenSSL bug. The overall sentiment suggests that while these attacks aren't always easily exploitable, understanding and mitigating them is crucial for robust security.
A developer encountered a perplexing bug where multiple threads were simultaneously entering a supposedly protected critical section. The root cause was an unexpected optimization performed by the compiler. A loop containing a critical section, protected by EnterCriticalSection
and LeaveCriticalSection
, was optimized to move the EnterCriticalSection
call outside the loop. Consequently, the lock was acquired only once, allowing all loop iterations for a given thread to proceed concurrently, violating the intended mutual exclusion. This highlights the subtle ways compiler optimizations can interact with threading primitives, leading to difficult-to-debug concurrency issues.
Hacker News users discussed potential causes for the described bug where a critical section seemed to allow multiple threads. Some pointed to subtle issues with the provided code example, suggesting the LeaveCriticalSection
might be executed before the InitializeCriticalSection
, due to compiler reordering or other unexpected behavior. Others speculated about memory corruption, particularly if the CRITICAL_SECTION structure was inadvertently shared or placed in writable shared memory. The possibility of the debugger misleading the developer due to its own synchronization mechanisms also arose. Several commenters emphasized the difficulty of diagnosing such race conditions and recommended using dedicated tooling like Application Verifier, while others suggested simpler alternatives for thread synchronization in such a straightforward scenario.
This blog post details the surprisingly complex process of gracefully shutting down a nested Intel x86 hypervisor. It focuses on the scenario where a management VM within a parent hypervisor needs to shut down a child VM, also running a hypervisor. Simply issuing a poweroff command isn't sufficient, as it can leave the child hypervisor in an undefined state. The author explores ACPI shutdown methods, explaining that initiating shutdown from within the child hypervisor is the cleanest approach. However, since external intervention is sometimes necessary, the post delves into using the hypervisor's debug registers to inject a shutdown signal, ultimately mimicking the internal ACPI process. This involves navigating complexities of nested virtualization and ensuring data integrity during the shutdown sequence.
HN commenters generally praised the author's clear writing and technical depth. Several discussed the complexities of hypervisor development and the challenges of x86 specifically, echoing the author's points about interrupt virtualization and hardware quirks. Some offered alternative approaches to the problems described, including paravirtualization and different ways to handle interrupt remapping. A few commenters shared their own experiences wrestling with similar low-level x86 intricacies. The overall sentiment leaned towards appreciation for the author's willingness to share such detailed knowledge about a typically opaque area of software.
"A Tale of Four Kernels" examines the performance characteristics of four different operating system microkernels: Mach, Chorus, Windows NT, and L4. The paper argues that microkernels, despite their theoretical advantages in modularity and flexibility, have historically underperformed monolithic kernels due to high inter-process communication (IPC) costs. Through detailed measurements and analysis, the authors demonstrate that while Mach and Chorus suffer significantly from IPC overhead, L4's highly optimized IPC mechanisms allow it to achieve performance comparable to monolithic systems. The study reveals that careful design and implementation of IPC primitives are crucial for realizing the potential of microkernel architectures, with L4 showcasing a viable path towards efficient and flexible OS structures. Windows NT, despite being marketed as a microkernel, is shown to have a hybrid structure closer to a monolithic kernel, sidestepping the IPC bottleneck but also foregoing the modularity benefits of a true microkernel.
Hacker News users discuss the practical implications and historical context of the "Four Kernels" paper. Several commenters highlight the paper's effectiveness in teaching OS fundamentals, particularly for those new to the subject. The simplicity of the kernels, along with the provided code, allows for easy comprehension and experimentation. Some discuss how valuable this approach is compared to diving straight into a complex kernel like Linux. Others point out that while pedagogically useful, these simplified kernels lack the complexities of real-world operating systems, such as memory management and device drivers. The historical significance of MINIX 3 is also touched upon, with one commenter mentioning Tanenbaum's involvement and the influence of these kernels on educational materials. The overall sentiment is that the paper is a valuable resource for learning OS basics.
macOS historically handled null pointer dereferences by trapping them, leading to immediate application crashes. This was achieved by mapping the first page of virtual memory to an inaccessible region. Over time, increasing demands for performance, especially from Java, prompted Apple to introduce "guarded pages" in macOS 10.7 (Lion). This optimization allowed for a small window of usable memory at address zero, improving performance for frequently checked null references but introducing the risk of silent memory corruption if a true null pointer dereference occurred. While efforts were made to mitigate these risks, the behavior shifted again in macOS 12 (Monterey) and later ARM-based systems, where the entire page at zero became usable. This means null pointer dereferences now consistently result in memory corruption, potentially leading to more difficult-to-debug issues.
Hacker News users discussed the nuances of null pointer dereferences on macOS and other systems. Some highlighted that the behavior described (where dereferencing a NULL pointer doesn't always crash) isn't unique to macOS and stems from virtual memory page zero being unmapped. Others pointed out the security implications, particularly in the kernel, where such behavior could be exploited. Several commenters mentioned the trade-off between debugging ease (catching null pointer dereferences early) and performance (the overhead of checking for null every time). The history of this design choice and its evolution in different macOS versions was also a topic of conversation, along with comparisons to other operating systems' handling of null pointers. One commenter noted the irony of Apple moving away from this behavior, as it was initially designed to make things less crashy. The utility of tools like scribble
for catching such errors was also mentioned.
The blog post "IO Devices and Latency" explores the significant impact of I/O operations on overall database performance, emphasizing that optimizing queries alone isn't enough. It breaks down the various types of latency involved in storage systems, from the physical limitations of different storage media (like NVMe drives, SSDs, and HDDs) to the overhead introduced by the operating system and file system layers. The post highlights the performance benefits of using direct I/O, which bypasses the OS page cache, for predictable, low-latency access to data, particularly crucial for database workloads. It also underscores the importance of understanding the characteristics of your storage hardware and software stack to effectively minimize I/O latency and improve database performance.
Hacker News users discussed the challenges of measuring and mitigating I/O latency. Some questioned the blog post's methodology, particularly its reliance on fio
and the potential for misleading results due to caching effects. Others offered alternative tools and approaches for benchmarking storage performance, emphasizing the importance of real-world workloads and the limitations of synthetic tests. Several commenters shared their own experiences with storage latency issues and offered practical advice for diagnosing and resolving performance bottlenecks. A recurring theme was the complexity of the storage stack and the need to understand the interplay of various factors, including hardware, drivers, file systems, and application behavior. The discussion also touched on the trade-offs between performance, cost, and complexity when choosing storage solutions.
"The Night Watch" argues that modern operating systems are overly complex and difficult to secure due to the accretion of features and legacy code. It proposes a "clean-slate" approach, advocating for simpler, more formally verifiable microkernels. This would entail moving much of the OS functionality into user space, enabling better isolation and fault containment. While acknowledging the challenges of such a radical shift, including performance concerns and the enormous effort required to rebuild the software ecosystem, the paper contends that the long-term benefits of improved security and reliability outweigh the costs. It emphasizes that the current trajectory of increasingly complex OSes is unsustainable and that a fundamental rethinking of system design is crucial to address the growing security threats facing modern computing.
HN users discuss James Mickens' humorous USENIX keynote, "The Night Watch," focusing on its entertaining delivery and insightful points about the complexities and frustrations of systems work. Several commenters praise Mickens' unique presentation style and the relatable nature of his anecdotes about debugging, legacy code, and the challenges of managing distributed systems. Some highlight specific memorable quotes and jokes, appreciating the blend of humor and technical depth. Others reflect on the timeless nature of the talk, noting how the issues discussed remain relevant years later. A few commenters express interest in seeing a video recording of the presentation.
This blog post presents a revised and more robust method for invoking raw OpenBSD system calls directly from C code, bypassing the standard C library. It improves upon a previous example by handling variable-length argument lists and demonstrating how to package those arguments correctly for system calls. The core improvement involves using assembly code to dynamically construct the system call arguments on the stack and then execute the syscall
instruction. This allows for a more general and flexible approach compared to hardcoding argument handling for each specific system call. The provided code example demonstrates this technique with the getpid()
system call.
Several Hacker News commenters discuss the impracticality of the raw syscall demo, questioning its real-world usefulness and emphasizing that libraries like libc exist for a reason. Some appreciated the technical depth and the exploration of low-level system interaction, viewing it as an interesting educational exercise. One commenter suggested the demo could be useful for specialized scenarios like writing a dynamic linker or a microkernel. There was also a brief discussion about the performance implications and the idea that bypassing libc wouldn't necessarily result in significant speed improvements, and might even be slower in some cases. Some users also debated the portability of the code and suggested alternative methods for achieving similar results.
This 1989 Xerox PARC paper argues that Unix, despite its strengths, suffers from a fragmented environment hindering programmer productivity. It lacks a unifying framework integrating tools and information, forcing developers to grapple with disparate interfaces and manually manage dependencies. The paper proposes an integrated environment, similar to Smalltalk or Interlisp, built upon a shared repository and incorporating features like browsing, version control, configuration management, and debugging within a consistent user interface. This would streamline the software development process by automating tedious tasks, improving code reuse, and fostering better communication among developers. The authors advocate for moving beyond the Unix philosophy of small, independent tools towards a more cohesive and interactive system that supports the entire software lifecycle.
Hacker News users discussing the Xerox PARC paper lament the lack of a truly integrated computing environment, even decades later. Several commenters highlight the continued relevance of the paper's criticisms of Unix's fragmented toolset and the persistent challenges in achieving seamless interoperability. Some point to Smalltalk as an example of a more integrated system, while others mention Lisp Machines and Oberon. The discussion also touches upon the trade-offs between integration and modularity, with some arguing that Unix's modularity, while contributing to its fragmentation, is also a key strength. Others note the influence of the internet and the web, suggesting that these technologies shifted the focus away from tightly integrated desktop environments. There's a general sense of nostalgia for the vision presented in the paper and a recognition of the ongoing struggle to achieve a truly unified computing experience.
1984 saw the rise of networked filesystems like NFS, which offered performance comparable to local filesystems, and the introduction of the Andrew File System (AFS), designed for large-scale distributed environments with client-side caching and whole-file serving. Research focused on improving performance and reliability, with log-structured filesystems like LFS emerging to optimize write operations. Additionally, the standardization of file systems continued, with work on the ISO 9660 standard for CD-ROMs solidifying the format's widespread adoption. This year highlighted the increasing importance of networking and the evolving demands placed upon file systems for both performance and portability.
The Hacker News comments discuss the blog post's focus on the early days of networked filesystems, particularly NFS. Several commenters share their own experiences with early NFS, highlighting its initial slow performance and eventual improvements. Some discuss the influence of Sun Microsystems and the rise of distributed systems. Others delve into technical details like caching, consistency models, and the challenges of implementing distributed locks. A few comments compare NFS to other contemporary filesystems and contemplate the enduring relevance of some of the challenges faced in the 1980s. There's a general appreciation for the historical perspective offered by the blog post.
This presentation compares and contrasts Fuchsia's component architecture with Linux containers. It explores how both technologies approach isolation, resource management, and inter-process communication. The talk delves into the underlying mechanisms of each, highlighting Fuchsia's capability-based security model and its microkernel design as key differentiators from containerization solutions built upon Linux's monolithic kernel. The goal is to provide a clear understanding of the strengths and weaknesses of each approach, allowing developers to better evaluate which technology best suits their specific needs.
HN commenters generally expressed skepticism about Fuchsia's practical advantages over Linux containers. Some pointed out the significant existing investment in container technology and questioned whether Fuchsia offered enough improvement to justify switching. Others noted Fuchsia's apparent complexity and lack of clear benefits in terms of security or performance. A few commenters raised concerns about software availability on Fuchsia, specifically mentioning the lack of common tools like strace
and gdb
. The overall sentiment leaned towards a "wait and see" approach, with little enthusiasm for Fuchsia as a container replacement.
The author meticulously debugged a mysterious issue where transferring Apple DOS 3.3 system files to a blank diskette sometimes resulted in a bootable disk, and sometimes a non-bootable one, despite seemingly identical procedures. Through painstaking analysis of the DOS 3.3 source code and assembly-level debugging, they discovered the culprit: a timing-sensitive bug within the SYS.COM
program related to how it handled track zero formatting. Specifically, SYS.COM
occasionally failed to wait for the drive head to settle after seeking to track zero before writing, resulting in corrupted data on the disk. This timing issue was sensitive to drive mechanics and environmental factors, explaining the intermittent nature of the problem. The author's fix involved adding a small delay within SYS.COM
to ensure the drive head had stabilized before writing, resolving the frustrating bug and guaranteeing consistent creation of bootable disks.
Several Hacker News commenters praised the author's clear and detailed write-up of the bug hunt, appreciating the methodical approach and the insights into early DOS development. Some shared their own experiences with similar bugs and debugging processes in other systems. One commenter pointed out the historical significance of relying on undocumented behavior, a common practice at the time due to limited documentation. Others discussed the challenges of working with older hardware and software, and the satisfaction of successfully solving such intricate problems. The overall sentiment reflects admiration for the detective work involved and nostalgia for the era of simpler, yet more opaque, computing.
Jon Blow reflects on the concept of a "daylight computer," a system designed for focused work during daylight hours. He argues against the always-on, notification-driven nature of modern computing, proposing a machine that prioritizes deep work and mindful engagement. This involves limiting distractions, emphasizing local data storage, and potentially even restricting network access. The goal is to reclaim a sense of control and presence, fostering a healthier relationship with technology by aligning its use with natural rhythms and promoting focused thought over constant connectivity.
Hacker News users largely praised the Daylight Computer project for its ambition and innovative approach to personal computing. Several commenters appreciated the focus on local-first software and the potential for increased privacy and control over data. Some expressed skepticism about the project's feasibility and the challenges of building a sustainable ecosystem around a niche operating system. Others debated the merits of the chosen hardware and software stack, suggesting alternatives like RISC-V and questioning the reliance on Electron. A few users shared their personal experiences with similar projects and offered practical advice on development and community building. Overall, the discussion reflected a cautious optimism about the project's potential, tempered by a realistic understanding of the difficulties involved in disrupting the established computing landscape.
Despite Windows 10's approaching end-of-life in October 2025, nearly half of Steam users are still using the operating system, according to the latest Steam Hardware Survey. While Windows 11 adoption is slowly growing, it still sits significantly behind Windows 10, leaving a large portion of PC gamers potentially facing security risks and a lack of support in the near future.
Hacker News users discussed the implications of nearly half of Steam users still running Windows 10, despite its approaching end-of-life. Some questioned the statistic's accuracy, suggesting the data might include Windows Server instances or older, unsupported Windows builds lumped in with Windows 10. Others pointed out the apathy many users feel towards upgrading, especially gamers who prioritize stable systems over new features. Several commenters mentioned the potential security risks of staying on an unsupported OS, while others downplayed this, arguing that games often run in sandboxed environments. The cost of upgrading, both in terms of hardware and software, was also a recurring theme, with some suggesting Microsoft's aggressive upgrade tactics in the past have led to distrust and reluctance to upgrade. Finally, some users speculated that many "Windows 10" users might actually be running Windows 11 but misreported due to Steam's detection methods.
An interactive, annotated version of the classic "Unix Magic" poster has been created. This online resource allows users to explore the intricate diagram of Unix commands and their relationships. By clicking on individual commands, users can access descriptions, examples, and links to further resources, providing a dynamic and educational way to learn or rediscover the power of the Unix command line. The project aims to make the dense information of the original poster more accessible and engaging for both beginners and experienced Unix users.
Commenters on Hacker News largely praised the interactive Unix magic poster for its nostalgic value, clear presentation, and educational potential. Several users reminisced about their experiences with the original poster and expressed appreciation for the updated, searchable format. Some highlighted the project's usefulness as a learning tool for newcomers to Unix, while others suggested improvements like adding links to man pages or expanding the command explanations. A few pointed out minor inaccuracies or omissions but overall considered the project a valuable resource for the Unix community. The clean interface and ease of navigation were also frequently mentioned as positive aspects.
Douglas McIlroy, the original author of the Unix spell
command, responded to an article detailing its inner workings with further insights into its development. He clarified that the efficient hashing used wasn't a conscious optimization but rather a side effect of the limited memory available on the PDP-7. The stop word list was chosen pragmatically to shrink the dictionary size. McIlroy also revealed that he experimented with stemming algorithms, ultimately discarding them due to excessive performance overhead and concerns about false positives. He highlighted the importance of spell
's collaborative development, with Steve Johnson's later refinements significantly improving its accuracy and efficiency.
HN commenters discuss McIlroy's response regarding the original Unix spell program. Several express fascination with the historical context and McIlroy's continued engagement with the topic. Some highlight the elegance and efficiency of the original implementation, particularly its use of hashing and minimal resources. Others note the contrast between then-current hardware limitations and modern capabilities, marveling at what was achieved with so little. A few commenters delve into specific technical details, such as the choice of hashing algorithms and the use of a 64KB PDP-11. The overall sentiment is one of appreciation for both McIlroy's contribution and the ingenuity of early Unix development.
This blog post details how to leverage the Rust standard library (std
) within applications running on the NuttX Real-Time Operating System (RTOS), a common choice for embedded systems. The author demonstrates a method to link the Rust std
components, specifically write()
for console output, with NuttX's system calls. This allows developers to write Rust code that feels idiomatic, using familiar functions like println!()
, while still targeting the resource-constrained environment of NuttX. The process involves creating a custom target specification JSON file and implementing shim
functions that bridge the gap between the Rust standard library's expectations and the underlying NuttX syscalls. The result is a simplified development experience, enabling more portable and maintainable Rust code on embedded platforms.
Hacker News users discuss the challenges and advantages of using Rust with NuttX. Some express skepticism about the real-world practicality and performance benefits, particularly regarding memory usage and the overhead of Rust's safety features in embedded systems. Others highlight the potential for improved reliability and security that Rust offers, contrasting it with the inherent risks of C in such environments. The complexities of integrating Rust's memory management with NuttX's existing mechanisms are also debated, along with the potential need for careful optimization and configuration to realize Rust's benefits in resource-constrained systems. Several commenters point out that while intriguing, the project is still experimental and requires more maturation before becoming a viable option for production-level embedded development. Finally, the difficulty of porting existing NuttX drivers to Rust and the lack of a robust Rust ecosystem for embedded development are identified as potential roadblocks.
Chimera Linux is focusing on simplicity and performance in its desktop environment. The project uses a custom-built desktop built on Wayland, emphasizing minimal dependencies and a streamlined experience. This includes a basic compositor called Chimera-wm, along with self-developed components like a file manager and terminal emulator, to minimize bloat and maintain a tight control over the user experience. While still under heavy development, the project aims to provide a fast, clean, and easily adaptable desktop environment built from the ground up.
HN commenters generally express interest in Chimera Linux's approach of using a modern init system and focusing on a straightforward desktop experience. Some praise its potential for stability and performance by sticking with known-good components. Others are skeptical of its niche appeal, questioning whether simplifying the desktop is a significant enough draw. A few commenters raise concerns about the sustainability of a project reliant on a single developer, while others commend the developer's clear vision and execution. The discussion also touches on the limitations of systemd and the challenges of balancing minimalism with user expectations. Some express hope for Chimera becoming a viable alternative to established distributions.
Dan Luu's "Working with Files Is Hard" explores the surprising complexity of file I/O. While seemingly simple, file operations are fraught with subtle difficulties stemming from the interplay of operating systems, filesystems, programming languages, and hardware. The post dissects various common pitfalls, including partial writes, renaming and moving files across devices, unexpected caching behaviors, and the challenges of ensuring data integrity in the face of interruptions. Ultimately, the article highlights the importance of understanding these complexities and employing robust strategies, such as atomic operations and careful error handling, to build reliable file-handling code.
HN commenters largely agree with the premise that file handling is surprisingly complex. Many shared anecdotes reinforcing the difficulties encountered with different file systems, character encodings, and path manipulation. Some highlighted the problems of hidden characters causing issues, the challenges of cross-platform compatibility (especially Windows vs. *nix), and the subtle bugs that can arise from incorrect assumptions about file sizes or atomicity. A few pointed out the relative simplicity of dealing with files in Plan 9, and others mentioned more modern approaches like using memory-mapped files or higher-level libraries to abstract away some of the complexity. The lack of libraries to handle text files reliably across platforms was a recurring theme. A top comment emphasizes how corner cases, like filenames containing newlines or other special characters, are often overlooked until they cause real-world problems.
Nick Janetakis's blog post explores the maximum number of Alpine Linux packages installable at once. He systematically tested installation limits, encountering various errors related to package database size, memory usage, and filesystem capacity. Ultimately, he managed to install around 7,800 packages simultaneously before hitting unavoidable resource constraints, demonstrating that while Alpine's package manager can technically handle a vast number of packages, practical limitations arise from system resources. His experiment highlights the balance between package manager capabilities and the realistic constraints of a system's available memory and storage.
Hacker News users generally agree with the article's premise that Alpine Linux's package manager allows for installing a remarkably high number of packages simultaneously, far exceeding other distributions. Some commenters point out that this isn't necessarily a practical metric, arguing it's more of a fun experiment than a reflection of real-world usage. A few suggest the high number is likely due to Alpine's smaller package size and its minimalist approach. Others discuss the potential implications for dependency management and the possibility of conflicts arising from installing so many packages. One commenter questions the significance of the experiment, suggesting a focus on package quality and usability is more important than sheer quantity.
The blog post argues that file systems, particularly hierarchical ones, are a form of hypermedia that predates the web. It highlights how directories act like web pages, containing links (files and subdirectories) that can lead to other content or executable programs. This linking structure, combined with metadata like file types and modification dates, allows for navigation and information retrieval similar to browsing the web. The post further suggests that the web's hypermedia capabilities essentially replicate and expand upon the fundamental principles already present in file systems, emphasizing a deeper connection between these two technologies than commonly recognized.
Hacker News users largely praised the article for its clear explanation of file systems as a foundational hypermedia system. Several commenters highlighted the elegance and simplicity of this concept, often overlooked in the modern web's complexity. Some discussed the potential of leveraging file system principles for improved web experiences, like decentralized systems or simpler content management. A few pointed out limitations, such as the lack of inherent versioning in basic file systems and the challenges of metadata handling. The discussion also touched on related concepts like Plan 9 and the semantic web, contrasting their approaches to linking and information organization with the basic file system model. Several users reminisced about early computing experiences and the directness of navigating files and folders, suggesting a potential return to such simplicity.
This blog post explores using NetBSD's native graphics capabilities without relying on the X Window System (X11). The author demonstrates direct framebuffer access using libraries like wscons and libcaca for simple graphics and text output, highlighting the performance benefits and reduced complexity compared to a full X11 setup. This approach is particularly advantageous for embedded or resource-constrained systems, or situations where a minimal graphical interface suffices. The post details setting up a NetBSD virtual machine, configuring wscons, and provides code examples using libcaca to draw shapes and text directly to the screen, showcasing the simplicity and directness of this method.
HN commenters largely praised the elegance and simplicity of NetBSD's native graphics stack, contrasting it favorably with the complexity of X11. Several pointed out the historical context, noting that this approach harkens back to simpler times and offers a refreshing alternative to the bloat of modern desktop environments. Some expressed interest in exploring NetBSD specifically because of this feature. A few commenters questioned the practicality for everyday use, citing the limited software ecosystem that supports it. Others discussed the performance implications, with some suggesting it could be faster than X11 in certain scenarios. There was also discussion of similar approaches in other operating systems, such as Framebuffer and Wayland.
/etc/glob
was an early Unix mechanism (predating regular expressions) allowing users to create named patterns representing sets of filenames, simplifying command-line operations. These patterns, using globbing characters like *
and ?
, were stored in /etc/glob
and could be referenced by name prefixed with g
. While conceptually powerful, /etc/glob
suffered from limited wildcard support and was eventually superseded by more powerful and flexible tools like shell globbing and regular expressions. Its existence offers a glimpse into the evolution of filename pattern matching and Unix's pursuit of concise yet powerful user interfaces.
HN commenters discuss the blog post's exploration of /etc/glob
in early Unix. Several highlight the post's clarification of the mechanism's purpose, not as filename expansion (handled by the shell), but as a way to store user-specific command aliases predating aliases and shell functions. Some commenters share anecdotes about encountering this archaic feature, while others express fascination with this historical curiosity and the evolution of Unix. The overall sentiment is appreciation for the post's shedding light on a forgotten piece of Unix history and prompting reflection on how modern systems have evolved. Some debate the actual impact and usage prevalence of /etc/glob
, with some suggesting it was likely rarely used even in early Unix.
The blog post "Right to root access" argues that users should have complete control over the devices they own, including root access. It contends that manufacturers artificially restrict user access for anti-competitive reasons, forcing users into walled gardens and limiting their ability to repair, modify, and truly own their devices. This restriction extends beyond just software to encompass firmware and hardware, hindering innovation and consumer freedom. The author believes this control should be a fundamental digital right, akin to property rights in the physical world, empowering users to fully utilize and customize their technology.
HN users largely agree with the premise that users should have root access to devices they own. Several express frustration with "walled gardens" and the increasing trend of manufacturers restricting user control. Some highlight the security and repairability benefits of root access, citing examples like jailbreaking iPhones to enable security features unavailable in the official iOS. A few more skeptical comments raise concerns about users bricking their devices and the potential for increased malware susceptibility if users lack technical expertise. Others note the conflict between right-to-repair legislation and software licensing agreements. A recurring theme is the desire for modular devices that allow component replacement and OS customization without voiding warranties.
This guide provides a comprehensive introduction to BCPL programming on the Raspberry Pi. It covers setting up a BCPL environment, basic syntax and data types, control flow, procedures, and input/output operations. The guide also delves into more advanced topics like separate compilation, creating libraries, and interfacing with the operating system. It includes numerous examples and exercises, making it suitable for both beginners and those with prior programming experience looking to explore BCPL. The document emphasizes BCPL's simplicity and efficiency, particularly its suitability for low-level programming tasks on resource-constrained systems like the Raspberry Pi.
HN commenters expressed interest in BCPL due to its historical significance as a predecessor to C and its influence on Go. Some recalled using BCPL in the past, highlighting its simplicity and speed, and contrasting its design with C. A few users discussed specific aspects of the document, such as the choice of Raspberry Pi and the use of pre-built binaries, while others lamented the lack of easily accessible BCPL resources today. Several pointed out the educational value of the guide, particularly for understanding compiler construction and the evolution of programming languages. Overall, the comments reflected a mix of nostalgia, curiosity, and appreciation for BCPL's role in computing history.
Summary of Comments ( 195 )
https://news.ycombinator.com/item?id=43653672
Hacker News users discuss the implications of Fedora's push for reproducible builds, focusing on the practical challenges. Some express skepticism about achieving true reproducibility given the complexity of build environments and dependencies. Others highlight the security benefits, emphasizing the ability to verify package integrity and prevent malicious tampering. The discussion also touches on the potential trade-offs, like increased build times and the need for stricter control over build processes. A few commenters suggest that while perfect reproducibility might be difficult, even partial reproducibility offers significant value. There's also debate about the scope of the project, with some wondering about the inclusion of non-free firmware and the challenges of reproducing hardware-specific optimizations.
The Hacker News post "Fedora change aims for 99% package reproducibility" generated a moderate discussion with several insightful comments. Many commenters expressed support for the initiative, viewing reproducible builds as a crucial step towards enhancing software security and trustworthiness.
One compelling comment highlighted the significance of reproducibility in verifying the integrity of downloaded packages, ensuring they haven't been tampered with. This resonates with the broader security concerns around supply chain attacks, where malicious actors compromise software during the build process. Reproducibility offers a mechanism to verify the authenticity of builds by independently recreating them and comparing the results.
Another commenter delved into the technical challenges of achieving full reproducibility, particularly with aspects like timestamps and build paths embedded within binaries. They emphasized the need for careful consideration of these details to ensure consistent build outputs. This point underscores the complexity of implementing reproducible builds and the meticulous effort required by package maintainers.
Some users questioned the practicality of aiming for 99% reproducibility, wondering about the remaining 1% and the potential difficulties in achieving perfect reproducibility. This prompted a discussion about the trade-offs between striving for ideal reproducibility and the pragmatic limitations imposed by certain software components or build processes.
Furthermore, a comment mentioned the importance of tools and infrastructure for verifying reproducibility, suggesting that simply rebuilding packages isn't sufficient. Robust verification mechanisms are essential for ensuring the integrity and consistency of the reproduced builds.
Several comments also touched upon the broader benefits of reproducible builds beyond security, such as easier debugging, improved transparency, and greater community involvement in the software development lifecycle. These comments showcase the wide-ranging impact of reproducible builds on the software ecosystem.
Overall, the comments on Hacker News generally demonstrate a positive reception towards Fedora's initiative for reproducible builds, recognizing its potential to improve software security and reliability. The discussion also acknowledges the technical complexities and the need for robust tooling to effectively implement and verify reproducible builds.