The #trace directive in OCaml’s interactive toplevel (ocaml or utop) logs function calls and returns, showing you exactly what arguments go in and what values come back out. This is invaluable for debugging recursive functions and understanding execution flow. Basic Usage Define a function and enable tracing with #trace: # let rec factorial n =…
Accessing Linux filesystems from Windows is useful when dual-booting, migrating data, or recovering files. Read-only access is essential to prevent accidental corruption of ext4 metadata and data. Why Read-Only Access Matters Ext4 is designed for Linux environments. Windows drivers lack complete understanding of ext4 journaling, extended attributes, and other advanced features. Writing through an incomplete…
There are several reliable methods to generate random strings of a specific length in bash. The choice depends on your character set requirements and use case. Using tr with /dev/urandom The tr command combined with /dev/urandom is the most portable and straightforward approach: tr -dc “[:alpha:]” < /dev/urandom | head -c 10 This produces a…
Broken links damage SEO, hurt user experience, and undermine site credibility. Checking for them should be part of your regular maintenance routine. Here’s what’s available in 2026. Online Tools W3C Link Checker (http://validator.w3.org/checklink) remains a solid option for checking individual pages. Point it at a URL and it crawls the page’s links, reporting broken ones…
Redis is an in-memory data structure store designed for speed and simplicity. Understanding its architecture and consistency guarantees is essential for deploying it correctly in production systems. Core Architecture Redis operates as a single-threaded, event-driven server that uses an in-memory data store with optional persistence. The single-threaded nature simplifies reasoning about concurrent access — all…
Vim’s regex engine is powerful but requires understanding its syntax rules, which differ significantly from standard POSIX extended regex. Whether you’re doing basic substitutions or complex text transformations, knowing how Vim handles regex patterns will save you hours of frustration. Vim Regex Basics Vim supports multiple regex engines, controlled by the magic setting. By default,…
Determining the number of CPU cores available on a Linux system is essential for performance tuning, application configuration, and capacity planning. Several approaches exist depending on what information you need. Quick check: nproc The simplest way to get the number of CPU cores is nproc: $ nproc 8 This reports the number of logical processors…
To replace strings across one or more columns in MySQL tables, use the REPLACE() function with an UPDATE statement. This is useful when migrating domains, fixing URLs, updating API endpoints, or correcting data patterns at scale. Basic Syntax UPDATE table_name SET column_name = REPLACE(column_name, ‘old_string’, ‘new_string’) WHERE column_name LIKE ‘%old_string%’; The WHERE clause isn’t required,…
To check which storage engine a table uses, query the information_schema database: SELECT ENGINE FROM information_schema.TABLES WHERE TABLE_SCHEMA = ‘database_name’ AND TABLE_NAME = ‘table_name’; Replace database_name and table_name with your actual values. You can also use the SHOW TABLE STATUS command for a quicker view: SHOW TABLE STATUS FROM database_name WHERE Name = ‘table_name’\G The…
If you need basic image editing without installing software or paying Photoshop’s subscription, several solid online options exist. Here’s what works well in 2026. Pixlr Pixlr remains a solid choice for straightforward editing. The web-based editor handles layers, filters, and common adjustments without much friction. Free tier covers most basic work, though premium features unlock…
Choosing the right number of mappers and reducers directly impacts Hadoop job performance. This isn’t a set-and-forget configuration—it depends on your cluster characteristics, data size, and task complexity. Mapper Configuration The number of mappers is primarily determined by the number of HDFS blocks in your input files. Each block typically generates one map task by…
Facebook’s engineering team has long been vocal about their heavy reliance on MySQL to power one of the world’s largest platforms. Understanding their approach offers valuable insights for anyone managing databases at scale. Storage Engine Philosophy Facebook treats MySQL as a generic data manipulation and storage engine rather than a monolithic application database. This architectural…
Chrome on iOS implements aggressive caching to improve browsing performance, but this can prevent you from seeing the latest versions of pages, stylesheets, and scripts. Unlike Safari’s convenient long-press refresh button, Chrome’s cache management is less intuitive. The Nuclear Option: Clear All Cache The most straightforward approach is clearing all cached data: Open Chrome Tap…
If you need to clean up spam content across your MyBB forum quickly, the Goodbye Spammer plugin automates the process of banning a user and removing all their content in one operation. Installation Download the Goodbye Spammer plugin from the MyBB Mods site, then: Upload ./inc/plugins/goodbyespammer.php to ./inc/plugins/ Upload ./inc/languages/english/goodbyespammer.lang.php to ./inc/languages/english/ Navigate to ACP…
You can run OCaml scripts directly from the command line with a shebang, similar to bash or Python. This requires making the file executable and using the proper interpreter directive. Basic Script Setup Create a file with a .ml extension and add a shebang at the top: #!/usr/bin/env ocaml print_endline “Hello world!”;; Then make it…
Font sizes in Gnuplot plots often appear too small when scaling images down for papers or presentations. You can control font sizes at multiple levels: globally for the terminal, for axis labels and tick marks, for legends, and for individual text elements. Global Terminal Font Size Set a default font and size for your entire…
The common claim that cin is significantly slower than scanf in C++ is partially true, but only when comparing default configurations. The reality is more nuanced. Why cin Can Be Slower by Default By default, C++ streams maintain synchronization with C stdio streams (stdin, stdout, stderr). This synchronization requires additional overhead because the library must…
OCaml’s int type size depends on your platform’s architecture. On 64-bit systems, int is 63 bits; on 32-bit systems, it’s 31 bits. This catches many people off guard when they test bitwise operations. Here’s why: OCaml uses one bit as a tag to distinguish integers from pointers at runtime (the least significant bit). So on…
OCaml provides robust FFI (Foreign Function Interface) capabilities for calling C code. This is essential when you need to use existing C libraries or write performance-critical sections in C. Using the Unix Module The simplest approach for Unix/Linux system calls is the built-in Unix module, which wraps common POSIX functions without requiring manual FFI binding….
Transactional memory (TM) is a synchronization mechanism that simplifies concurrent programming by allowing multiple threads to execute code atomically without explicit lock management. If you’re getting into this area, here are the best resources and practical approaches to build solid understanding. Foundational Reading The classic reference is still Transactional Memory by James R. Larus and…