Year: 2025
PHP
What is PHP?
PHP is a popular open-source scripting language primarily used for web development and creating dynamic content for websites. Here’s a brief overview: Here’s a simple example of PHP code: This script would output “Hello, World!” on the webpage when executed on a server with PHP installed. PHP has evolved over the years to support more […]
PHP
How to request an A record from a DNS server in PHP 8.3
In PHP 8.3, you can use the dns_get_record() function to query DNS records, including A records. Here’s an example of how to request an A record from a DNS server: Explanation: Example Output: If the domain has A records, the output will look like this:
PHP
How do I reverse an IP address for use in DNS BL?
Here’s a small function in PHP 8.3 that reverses an IPv4 address: Explanation: This ensures the function works safely and as expected.
Linux
Has Linux fixed the unix time bug yet?
The “Year 2038 problem” (also known as the 32-bit Unix time overflow bug) has largely been addressed in modern Linux systems and related software. So yes it has been fixed. Background on the Problem The issue arises because Unix time (the number of seconds since January 1, 1970, 00:00:00 UTC) is traditionally stored as a […]
Postfix
How do I block a domain name in postfix?
To block a domain name in Postfix, you can use the sender_access feature to reject emails from specific domains. Here’s a step-by-step guide: 1. Edit Postfix Configuration Open the main configuration file: Look for the smtpd_sender_restrictions line. If it doesn’t exist, add it, or modify it to include the check_sender_access directive: The permit ensures valid […]