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Constant lookup in Ruby can happen lexically or through the ancestry tree of the receiver(a class or module). You can identify which lookup rules are being applied by the context you're in or by the syntax being used to define a class or module.

A class body that is defined as class A::B::C; …; end will lookup constants through the ancestry tree when a constant is evaluated in its class body. Anytime you see A::B::C being used as syntax to define a class or lookup the value of a constant the ancestry tree is being used for the lookup.

Finding a Ruby memory leak using a time analysis

When developing a program in Ruby, you may sometimes encounter a memory leak. For a while now, Ruby has a facility to gather information about what objects are laying around: ObjectSpace.

There are several approaches one can take to debug a leak. This discusses a time-based approach, where a full memory dump is generated every, say, 5 minutes, during a time that the memory leak is showing up. Afterwards, one can look at all the objects, and find out which ones are staying around, causing the

	# List of cheatsheet for linux find.
	# Taken from here http://alvinalexander.com/unix/edu/examples/find.shtml

	# basic 'find file' commands
	# --------------------------
	find / -name foo.txt -type f -print # full command
	find / -name foo.txt -type f # -print isn't necessary
	find / -name foo.txt # don't have to specify "type==file"
	find . -name foo.txt # search under the current dir
	find . -name "foo.*" # wildcard