Focused on sharing practical Linux technology content, covering Linux fundamentals, applications, tools, as well as databases, operating systems, network security, and other technical knowledge.
This article covers 10 advanced SQL concepts — CTEs, recursive CTEs, temporary functions, CASE WHEN pivoting, EXCEPT vs NOT IN, self-joins, ranking functions, delta calculations, running totals, and datetime manipulation — with practical code examples for data science interviews.
This article compiles seven expert perspectives on why Linux dominates the server market, covering historical security flaws in Windows/IIS, performance advantages of epoll-based web servers, lower licensing costs, lighter resource footprint, native container support, stronger open-source ecosystem, and the Matthew effect that cemented Linux's position.
This comprehensive guide covers Linux memory fundamentals, address space layout, buddy and slab allocation algorithms, kernel/user memory APIs, page fault handling, shared memory, common C/C++ memory pitfalls, and essential monitoring tools for backend developers.
This illustrated guide explains TCP and UDP protocols, covering TCP header structure, flow control via sliding windows, congestion control algorithms (slow start, congestion avoidance, fast retransmit/recovery), three-way handshake and four-way handshake mechanics with sequence numbers, SYN flood attacks, and a detailed TCP vs UDP comparison across connection model, reliability, and header overhead.
This article explains three Linux commands—dd, truncate, and fallocate—for quickly creating large files of specific sizes, comparing their mechanisms, speed, and whether they produce sparse files, with practical examples for generating 2GB test files.
This article explains Linux file permission fundamentals, covering file type indicators, owner/group/other permission bits, and practical usage of chown, chgrp, and chmod with both numeric and symbolic modes through concrete command examples.
This article compares the Linux su and sudo commands, explaining differences in authentication methods, permission scope, security implications, audit logging, and ideal use cases to guide administrators in selecting the right privilege escalation tool.
This article explains Linux process states (TASK_RUNNING, TASK_INTERRUPTIBLE, TASK_UNINTERRUPTIBLE), the schedule() and wake_up_process() mechanisms, the lost wakeup race condition that occurs when a process checks a condition before setting its sleep state, and the correct pattern used in the Linux kernel—setting the state to interruptible before condition checking and looping with schedule()—to avoid indefinite sleep.
This article systematically introduces essential Linux performance analysis tools including vmstat, iostat, dstat, iotop, pidstat, top, htop, mpstat, netstat, ps, strace, lsof, and perf, explaining their usage, key metrics, and practical command examples for system monitoring and troubleshooting.
This article surveys ten Linux antivirus tools—including ClamAV, Sophos, and Firetools—covering their licensing models, detection capabilities, command-line or GUI interfaces, and suitability for servers or desktops to help administrators select appropriate protection.
