Slideshare Downloader

slideshare-downloader.sh

#!/bin/bash
# Author: Andrea Lazzarotto
# http://andrealazzarotto.com
# andrea.lazzarotto@gmail.com

# Slideshare Downloader
# This script takes a slideshare presentation URL as an argument and
# carves all the slides in flash format, then they are converted to
# and finally merged as a PDF

# License:
# Copyright 2010-2011 Andrea Lazzarotto
# This script is licensed under the Gnu General Public License v3.0.
# You can obtain a copy of this license here: http://www.gnu.org/licenses/gpl.html

# Usage:
# slideshare-downloader.sh URL [SIZE]

#-----------------------------------------------
# Modify 7/08/2011 by giudinvx
# Email  giudinvx[at]gmail[dot]com 
#-----------------------------------------------
validate_input() {
	# Performs a very basic check to see if the url is in the correct form
	URL=`echo "$1" | cut -d "#" -f 1 | cut -d "/" -f 1-5`
	DOMAIN=`echo "$URL" | cut -d "/" -f 3`
	CORRECT='www.slideshare.net'
	if [[ "$DOMAIN" != "$CORRECT" ]];
		then
			echo "Provided URL is not valid."
			exit 1
	fi
	
	if echo -n "$2" | grep "^[0-9]*$">/dev/null
		then SIZE=$2
		else
			SIZE=2000
			echo "Size not defined or invalid... defaulting to 2000."
	fi
}

check_dependencies() {
	# Verifies if all binaries are present
	DEP="wget sed seq swfdec-thumbnailer convert"
	ERROR="0"
	for i in $DEP; do
		WHICH="`which $i`"
		if [[ "x$WHICH" == "x" ]];
			then
				echo "Error: $i not found."
				ERROR="1"
		fi
	done
	if [ "$ERROR" -eq "1" ];
		then
			echo "You need to install some packages."
			echo "Remember: this script requires Imagemagick and Swfdec."
			exit 1
	fi
}

build_params() {
	# Gathers required information
	DOCSHORT=`echo "$1" | cut -d "/" -f 5`
	echo "Download of $DOCSHORT started."
	echo "Fetching information..."
	INFOPAGE=`wget -q -O - "$1"`
	DOCID=`echo "$INFOPAGE" | grep "doc=" | cut -d "=" -f 3 | cut -d "&" -f 1`
	if [[ "$DOCID" =~ ([a-z0-9-]+)$ ]]
	then
		DOCID=${BASH_REMATCH[0]}
	else
		echo $DOCID
		exit 1
	fi
	SLIDES=`echo "$INFOPAGE" | grep "totalSlides" | head -n 1 | sed -s "s/.*totalSlides//g" | cut -d ":" -f 2 | cut -d "," -f 1`
	echo "Slides: $SLIDES"
	echo "Size: $SIZE"
}

create_env() {
	# Finds a suitable name for the destination directory and creates it
	DIR=$DOCSHORT
	if [ -e "$DIR" ];
		then
			I="-1"
			OLD=$DIR
			while [ -e "$DIR" ]
			do
				I=$(( $I + 1 ))
				DIR="$OLD.$I"
			done
	fi
	mkdir "$DIR"
}

fetch_slides() {
	for i in $( seq 1 $SLIDES ); do
		echo "Downloading slide $i"
		wget "http://cdn.slidesharecdn.com/`echo $DOCID`-slide-`echo $i`.swf" -q -O "$DIR/slide-`echo $i`.swf"
	done
	echo "All slides downloaded."
}

convert_slides() {
	for i in $( seq 1 $SLIDES ); do
		echo "Converting slide $i"
		swfdec-thumbnailer -s $SIZE $DIR/slide-$i.swf $DIR/slide-$i.png 2>/dev/null
	done
	echo "All slides converted."
}

build_pdf() {
	IMAGES=`ls $DIR/*.png | sort -V`
	echo "Generating PDF..."
	convert $IMAGES -compress jpeg $DIR/$DOCSHORT.pdf
	echo "The PDF has been generated."
	echo "Find your presentation in: \"`pwd`/$DIR/$DOCSHORT.pdf\""
}

clean() {
	rm -rf $DIR/slide-*.swf
	rm -rf $DIR/slide-*.png
}

validate_input $1 $2
check_dependencies
build_params $URL
create_env
fetch_slides
convert_slides
build_pdf
clean