Category Archives: Programming

DIY “What’s My IP Address”

WhatsMyIP_web600
Have you ever wanted to access a home computer or server but you didn’t know your IP address? That’s probably because your IP address is dynamic and changes periodically. So how do you find out what your IP address is? If you’re on your home network, then it’s easy by using any number of websites whose sole purpose is to tell you what your IP address is, for example www.whatsmyip.org. But what if you’re away from home and your IP address changes? Again, there are services to help you with this, but in this article, I’m going to show you how to easily setup your own service.

Continue reading

Regular Expression Cheatsheet

Here’s a quick cheatsheet of the metacharacters used in regular expressions.

Metacharacter
Name
Matches
.dotany one character
[ ... ]character classany character listed
[^...]negated character classany character not listed
^caretthe position at the start of the line
$dollarthe position at the end of the line
\<backslash less-thanthe position at the start of the word
\>backslash greater-thanthe position at the end of the word
|or, barmatches either expression it separates
( ... )parenthesesused to limit scope of |
?question markone allowed; none required ("one optional")
*asteriskunlimited allowed; none required ("any amount OK")
+plusunlimited allowed; one required ("at least one")
\1, \2, ...back referencematches text previously matched within first, second, etc., set of parentheses
\backslashescape a metacharacter to match literally
{ ... }bracesInterval; counting quantifier; specify number of matches