De Morgan's laws in Ruby

The negation of a disjunction is the conjunction of the negations and The negation of a conjunction is the disjunction of the negations.

How to simplify nested ifs

If you have `if`s nested in this way: ``` if a if b 1 else 2 end else 3 end ``` You can flatten and simplify them into this: ...

How to run PostgreSQL if 'postmaster.pid' already exists

How to run PostgreSQL if it isn't starting because 'postmaster.pid' already exists

Ruby logger log levels

OK, it seems obvious but I always spend several minutes finding it. So I think it's a good idea to put it here.

How to include logo into devise messages

A quick guide how to include any file, in this case logo to devise messages

Labelary - an online ZPL editor

Labelary is an online ZPL (Zebra Programming Language) editor and viewer

http://labelary.com/viewer.html

Rubular - a Ruby regular expressions editor

Rubular is an online tool to check regular expressions written in Ruby.

http://rubular.com/