Working with environment variables in C is straightforward using POSIX APIs. The two primary functions are getenv() for retrieval and setenv() for modification. Getting Environment Variables Use getenv() to read an environment variable: #include <stdlib.h> #include <stdio.h> int main(void) { const char *path = getenv(“PATH”); if (path != NULL) { printf(“PATH: %s\n”, path); } else…
[md] Use setenv to set an environment variable in csh: setenv VARIABLE value Replace VARIABLE with the name of the variable and value with its value. The variable is immediately available in the current shell and inherited by child processes. ## Examples Set a simple variable: setenv PATH /usr/local/bin:/usr/bin:/bin setenv EDITOR vim setenv JAVA_HOME /usr/lib/jvm/java-17-openjdk…
Setting environment variables in Bash is one of the most fundamental skills for working with Linux command lines and shell scripts. Bash provides several ways to define and manage variables. Setting a Variable for the Current Shell MY_VAR=”hello world” Important: No spaces around the = sign. MY_VAR = “value” will produce an error because Bash…
iOS 7 redesigned the Calendar app with a new interface, and finding the list view (a chronological list of all events) isn’t immediately obvious. Here’s how to access it and make the most of the Calendar app. Access List View in iOS 7 Open the Calendar app Tap the list icon (three horizontal lines with…
C++ provides the <iomanip> header for controlling how data appears when printed to standard output. These manipulators give you precise control over formatting, alignment, precision, and radix. Basic Manipulators The most common manipulators are persistent (they remain active until changed) or stateless (they apply once and reset). Width and Alignment: #include <iostream> #include <iomanip> int…
When you need to page through error output from a command, you’ll run into the issue that less only receives stdout by default. Error messages go to stderr (file descriptor 2), so they’ll still scroll past on your terminal while stdout gets paged. Basic approach: combine stderr with stdout make 2>&1 | less The 2>&1…
Designated initializers for aggregate types with non-trivial members (like std::vector) have inconsistent support across GCC versions. This error typically appears when you try to initialize a struct containing standard library containers using designated initializer syntax in the wrong order. The Problem When you compile this code with older GCC versions: struct Stat { vector<int> vec;…
The nm command displays symbolic information from object files, libraries, and executables. It’s the standard tool for inspecting what functions and variables are defined or referenced in a static library (.a file). Basic usage List all symbols in a library: nm lib.a This outputs symbol names, but the default format can be hard to parse….
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 =…
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…
You can delete cookies from individual sites without clearing your entire browser cache. Here’s how: Via Settings UI Open chrome://settings/privacy in the address bar (or go to Settings > Privacy and security) Click Cookies and other site data Click All cookies and site data Use the search box to find the domain you want to…
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…
When you need to populate PDF forms with large datasets, manual entry becomes impractical. Scripting this process saves time and eliminates human error. Here’s how to automate PDF form filling using Python. Understanding PDF Form Filling PDF forms contain field names that can be programmatically populated. The process typically involves: Identifying field names in your…
If you’ve deactivated and reactivated the Disqus WordPress plugin but it’s still using the old forum ID and configuration, you need to clear the stored settings from your database. This is the most reliable way to force the plugin to re-initialize and prompt you for fresh configuration. Why This Happens WordPress stores plugin configuration in…
Cron is a minimal execution environment. Unlike your interactive shell, cron runs with a stripped-down environment containing only a few variables like PATH, MAILTO, and SHELL. Any variables you’ve defined in your shell profile won’t be available unless you explicitly source them in your crontab entries. The Problem If your cron job depends on environment…
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…
Installing WordPress in a subdirectory keeps your site root cleaner and makes it easier to manage core files separately from content. Here’s how to configure WordPress so the admin and core files live in /wordpress while the site appears at your domain root. Creating the Subdirectory Structure First, create the WordPress directory and set proper…
SSH is essential for serious shared hosting management — it beats FTP by a mile and gives you real shell access for development, deployment, and automation. Most reputable shared hosting providers support SSH, though availability and implementation vary. Major Providers with SSH Support DreamHost DreamHost has long supported SSH on shared hosting. You’ll need to…
If you’re trying to add a domain to a Dreamhost account and get the error “You can’t add that domain: already in our system,” the domain is already configured for DNS hosting in another Dreamhost account. You need to remove the DNS hosting from the original account before you can host it elsewhere. This process…
MySQL replication lets you maintain synchronized copies of your database across multiple servers. This is essential for high availability, read scaling, and backups. Here’s how to configure it properly. Prerequisites You need at least two MySQL instances: a primary (source) and one or more replicas. Both should run the same or compatible MySQL versions. MySQL…