A regular expression, or regex, is a sequence of characters that represents a pattern. They are commonly used in code and text processing. For instance,…
Category: Dictionary
Proxy servers
A proxy server sits between a client and one or more other servers. This article briefly looks at forward and reverse proxies.
MIME types
A MIME type identifies the type of a file. When a server sends resources to a web browser it includes the MIME type of each…
Hexadecimal (base-16) numbers
In my article about base-2 (binary) numbers I talked about the difference between the decimal (base-10) numbers we use in our everyday life and base-2…
Cryptography, encryption and hashes
Hashing and encryption are both forms of cryptography, but they work quite differently. This article briefly describes how they are different.
Root and intermediate certificates
SSL certificates are at the heart of connecting securely to websites. This article looks at where SSL certificates come from and how you can check…
Binary (base-2) numbers
To understand IPv4 addresses and networking you need to understand binary numbers. Put simply, you need to know why the decimal number 255 translates to…
MailDir and Mdbox
On cPanel servers emails are stored in one of two formats: Maildir or Mdbox. Both have their advantages and disadvantages. As a quick summary, the…
The PATH variable
Linux systems use lots of environment variables. Among others, there are variables that store your username ($USER) and the current directory ($PWD). One of the…