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How to run Perl in an interactive shell

An interactive shell is useful for quickly trying out different commands. While Ruby, Python, and Clojure come with interactive shells, Perl does not. However, it is easy to create one using this one-liner on Unix systems:

perl -e 'do{print("perl> ");$_x=<>;chomp $_x;print(eval($_x)."\n")}while($_x ne "q")'

The fastest remote directory rsync over ssh archival I can muster (40MB/s over 1gb NICs)

This creates an archive that does the following:

rsync (Everyone seems to like -z, but it is much slower for me)

a: archive mode - rescursive, preserves owner, preserves permissions, preserves modification times, preserves group, copies symlinks as symlinks, preserves device files.
H: preserves hard-links
A: preserves ACLs

OS X Screencast to animated GIF

This gist shows how to create a GIF screencast using only free OS X tools: QuickTime, ffmpeg, and gifsicle.

Instructions

To capture the video (filesize: 19MB), using the free "QuickTime Player" application:

I have two user accounts set up on my mac. User drew I use for most things, but if I'm making a screencast I'll switch to the demo user. I know that the demo user has a clean desktop, and the font size is larger than usual in my terminal and text editors, making everything a bit more legible when capturing the screen. When I record a screencast as the demo user, I save the file to /Users/Shared/screencasts. As I understand it, the /Users/Shared directory is supposed to be accessible to all user accounts on the mac. If I created and saved a screenflow document as the demo user, I should be able to read and write that file when logged in as user drew.

That was the theory, but it didn't always work out that well in practice. I would occasionally find that a directory was only writable by one user or the other. Perhaps I'd open a screenflow document as user drew and attempt to export the video to the same directory, only to find that the directory was owned by demo, meaning that I couldn't cr

Intro

Just some FYI, to get started:

I'm using a 16 GB Sandisk SD card.
I have a model B Pi, 512 MB RAM (not really relevant, thought I'd mention it).
Monitor and keyboard connected to the Pi itself, for now.
Network working, internet access.

Anonymising PDFs

PDF metadata

Metadata in PDF files can be stored in at least two places:

the Info Dictionary, a limited set of key/value pairs
XMP packets, which contain RDF statements expressed as XML

	#!/usr/bin/env runhaskell
	{-
	Print monthly average cashflow by account.

	$ average-cashflow.hs YEAR [JOURNALFILE]

	-}

	module Main where

	<?php

	/**
	* 3-letter IATA City Code to CityName conversion
	*
	* Usage:
	*
	* $city_name = City::code("LON");
	* // "London"
	*