Friday, January 13, 2012

A simple command-line Megaupload download manager

Have a bunch of megaupload links and ever felt the need for a simple, lightweight, text-based/command-line and eminently extensible script which does all the downloading for you?

Your search ends here!

Requirements

  1. wget: which is present by default in almost linux distros
  2. ruby and nokogiri: These can be installed as shown here.
Steps
  1. Save the script as megaupload_dm.rb
  2. Make it executable using chmod +x megaupload_dm.rb
  3. Install the dependencies
  4. Dump all your megaupload links to a file named megaupload_list.txt in the current directory. You can also insert any content or comments in this file
  5. Tweak the LinkFile and OutputDirectory variables to your liking.
  6. Limit the download rate by adding --limit-rate=100k to the wget command at line #43 (optional)
  7. Run it using ./megaupload_dm.rb
  8. Your files are downloaded to ~/Downloads directory!


#!/usr/bin/env ruby


# Is the url a valid one?
def valid?(url)
  url =~ %r|^http://www.megaupload.com/\?d=[a-zA-Z0-9]+$|
end

require 'rubygems'
require 'nokogiri'
require 'open-uri'

LinkFile = "./megaupload_list.txt"
OutputDirectory = "/home/vikas/Downloads"
TempFile = "/tmp/megaupload-tmp.html"


File.open(LinkFile, 'r') do |f|
  f.each_line do |link|

    link.strip!

    next unless valid?(link)

    begin

      puts "Fetching information for #{link} ..."
      `wget "#{link}" -U "Firefox/4.0.0" --quiet --output-document #{TempFile}`

      doc = Nokogiri::HTML(File.read(TempFile))

      # Filename and Direct Link
      fname = doc.css("div.downl_main div.download_file_name").first.content
      direct_link = doc.css("div.downl_main div.download_member_bl a").last.attributes['href'].value

      # Actual download
      puts "Downloading #{fname} ... \n"
      `wget -c -P "#{OutputDirectory}" -U "Firefox/3.6.3" "#{direct_link}"`
      puts "*********************************** DONE *******************************************"
      puts "\n\n"

      # Sleep 5 secs. Take some load off megaupload ;)
      sleep 5

    rescue
      puts "ERROR! FileNotFound or otherwise; Skipping this file...."
      puts "\n\n"
      next
    end

  end
end

Tuesday, January 3, 2012

A script to download wallpapers from wallpaperswide.com


Going through wallpapers websites like http://www.wallpaperswide.com/ and ever wondered how cool would it be if you have a magic wand with which you could download all the wallpapers without having to manually download the ten images in all of the 2500-odd pages?

Your search ends here!

Dependencies
  1. This script is written in Ruby. Most Linux distros ship a basic version of this scripting language. If not, install it along with rubygems using the following commands.
  2. This script needs wget utility to download. wget is shipped with almost all linux distros. If not, install it using your distro's package manager.
# If you don't use a Debian-based distro like Ubuntu or Linux Mint, replace 'apt-get' with your distro's package manager

# Install 'ruby' and 'rubygems' if not already installed
sudo apt-get install ruby rubygems

# Install 'wget' if not installed
sudo apt-get install wget

# Install 'nokogiri' gem
gem install --no-r{doc,i} nokogiri
  1. Save the following ruby code into a file named wallpaperswide_dot_com.rb
  2. Choose the resolution of the wallpapers you want to download. The list of resolutions supported are given in the beginning of the script. Tweak Resolution variable accordingly.
  3. Adjust the Output_Directory variable.
  4. Run the script by ruby wallpaperswide_dot_com.rb
  5. It'll be a 2+GB download depending on the resolution. If you desire to limit your download speed to say 100kbps, you could add an additional argument to the wget command (the third line from the end) like wget -c --limit-rate=100k -U "Firefox/4.5.6" ...;
#!/usr/bin/env ruby
#
#  Vikas Reddy
#
#  A little script to download ALL the wallpapers of a given
#  resolution from http://www.wallpaperswide.com/
#
#  Requirements
#  ============
#  Ruby Version: 1.9.2
#  Gems: nokogiri, open-uri
#  Other programs: wget
#
#
#  Available Resolutions
#  =====================
#
#  Wide
#  
#  * 16:10 960x600
#  * 16:10 1152x720
#  * 16:10 1280x800
#  * 16:10 1440x900
#  * 16:10 1680x1050
#  * 16:10 1920x1200
#  * 16:10 2560x1600
#  * 16:10 3840x2400
#  * 16:10 5120x3200
#  * 5:3 800x480
#  * 5:3 1280x768
#  
#  HD
#  
#  * 16:9 960x540
#  * 16:9 1024x576
#  * 16:9 1280x720
#  * 16:9 1366x768
#  * 16:9 1600x900
#  * 16:9 1920x1080
#  * 16:9 2048x1152
#  * 16:9 2400x1350
#  * 16:9 2560x1440
#  * 16:9 3554x1999
#  * 16:9 3840x2160
#  
#  Standard
#  
#  * 4:3 800x600
#  * 4:3 1024x768
#  * 4:3 1152x864
#  * 4:3 1280x960
#  * 4:3 1400x1050
#  * 4:3 1440x1080
#  * 4:3 1600x1200
#  * 4:3 1680x1260
#  * 4:3 1920x1440
#  * 4:3 2048x1536
#  * 4:3 2560x1920
#  * 4:3 2800x2100
#  * 4:3 3200x2400
#  * 4:3 4096x3072
#  * 5:4 1280x1024
#  * 5:4 2560x2048
#  * 5:4 3750x3000
#  
#  Mobile Ratio
#  
#  * VGA 240x320
#  * VGA 480x640
#  * VGA 320x240
#  * VGA 640x480
#  * WVGA 240x400
#  * WVGA 480x800
#  * WVGA 400x240
#  * WVGA 800x480
#  * HVGA 320x480
#  * HVGA 480x320
#  * HVGA 640x960
#  * HVGA 960x640
#  * iPad 1024x768
#  * iPad 768x1024
#  * HD 16:9 480x272
#  * HD 16:9 272x480
#  * Phone 176x220
#  * Phone 220x176
#  
#  Dual
#  
#  * 4:3 1600x600
#  * 4:3 2048x768
#  * 4:3 2304x864
#  * 4:3 2560x960
#  * 4:3 2800x1050
#  * 4:3 2880x1080
#  * 4:3 3200x1200
#  * 4:3 3360x1260
#  * 4:3 3840x1440
#  * 4:3 4096x1536
#  * 4:3 5120x1920
#  * 4:3 5600x2100
#  * 4:3 6400x2400
#  * 4:3 8192x3072
#  * 5:4 2560x1024
#  * 5:4 5120x2048
#  * 5:4 7500x3000
#  * 5:4 10240x4096
#  * 16:10 1920x600
#  * 16:10 2304x720
#  * 16:10 2560x800
#  * 16:10 2880x900
#  * 16:10 3360x1050
#  * 16:10 3840x1200
#  * 16:10 5120x1600
#  * 16:10 7680x2400
#  * 16:10 10240x3200
#  * 5:3 1600x480
#  * 5:3 2560x768
#  * 16:9 1920x540
#  * 16:9 2048x576
#  * 16:9 2560x720
#  * 16:9 3200x900
#  * 16:9 3840x1080
#  * 16:9 4096x1152
#  * 16:9 4800x1350
#  * 16:9 5120x1440
#  * 16:9 7108x2000
#  * 16:9 7680x2160
#  * 3:2 2880x960
#  * 3:2 4000x1333
#  * 3:2 2304x768
#  
#  Other
#  
#  * 3:2 1152x768
#  * 3:2 1440x960
#  * 3:2 2000x1333


require 'open-uri'
require 'nokogiri'

Resolution = "1600x900"
Base_URL   = "http://wallpaperswide.com/#{Resolution}-wallpapers-r/page/"
Output_Directory = "/home/vikas/Wallpapers/"

# Create the Output_Directory if needed
`mkdir -p "#{Output_Directory}"`

(1..2492).each do |page_num|

  # Go page by page
  url = Base_URL + page_num.to_s

  # Parse html
  f = open(url)
  doc = Nokogiri::HTML(f)

  # Loop over image-boxes
  doc.css("div.thumb").each do |wallp|

    # Extract wallpaper subpage url
    wallp.css("div[onclick]").attr("onclick").value =~ /prevframe_show\('(.*)'\)/
    subpage_url = $1
    subpage_url =~ %r|http://wallpaperswide\.com/[^/]+/([\w\d]+)\.html|

    # Generate url of the required wallpaper
    wallp_url = %|http://wallpaperswide.com/download/#{$1}-#{Resolution}.jpg|
   
    # Download... with a user-agent parameter just in case...
    # use '--limit-rate=100k' to limit download speed
    `wget -c -U "Firefox/4.5.6" -P "#{Output_Directory}" "#{wallp_url}"`
  end
end

Monday, January 2, 2012

A script to compile a latex-beamer presentation into all themes

I always wondered how great and handy would it be had I had a nifty script to compile my latex presentation using all the themes present in my current tex installation so that I can have a look at all the output files and choose the one which looks best.

And, this is the little bash shell script I've written to fulfill my need.
  1. Save this script into your Latex project directory
  2. Adjust the variables listed in the script to your liking ($themes_path and $output_directory)
  3. Give executable permission using "chmod +x $filename" or otherwise
  4. Execute it! It takes your ".tex" as the command-line argument and outputs the pdfs into a directory named "change_themes". There will be as many themes as your Beamer installation could possibly output.
PS: It'll not disturb/write to your original .tex file though. It just reads it.

#!/bin/bash

themes_path="/usr/share/texmf/tex/latex/beamer/base/themes/theme"
filename="$1"
output_directory="./change_themes"

# Needs the .tex file as the command-line argument
if [[ -z "$filename" ]]; then
    echo "Needs a command-line argument";
    exit;
fi

# Create the output directory if needed
if ! [[ -d "$output_directory" ]]; then
    mkdir -p "$output_directory";
fi

for theme in $themes_path/*.sty; do
    theme_name="$(echo "$(basename "$theme")" | sed -re 's/beamertheme(.*)\.sty/\1/')"
    sed -r "
s/usetheme\{(.*)\}/usetheme{$theme_name}/" "$filename" > "$output_directory/$filename"
    pdflatex -output-directory="
$output_directory" "$output_directory/$filename"
    pdf_fname="
$(basename "$filename" ".tex").pdf"
    pdf_fname_new="
${theme_name}_${pdf_fname}"
    mv "
$output_directory/$pdf_fname" "$output_directory/$pdf_fname_new"
done