Automatic LaTeX re-rendererer

refresh_latex.rb

#!/usr/bin/env ruby

# refresh_latex
# Automagically re-render LaTeX files and open the result in a PDF reader.
# Using Skim we can do all of this without losing focus to the editor,
# although I provide code to somewhat accomplish this with Preview.app
#
# As of right now it only works in OS X since it uses the "open" command.
# Feel free to port it to any platform you want to
#
# NOTE: requires the "listen" ruby gem
# Install it with the following command:
# gem install listen

require 'listen'

if ARGV.size == 0
  puts "You didn't tell me the LaTeX document you wanted to render!"
  exit 0
end

# Input argument is the path to the tex file
filename = File.absolute_path(ARGV[0])

# Name without extension
name = File.basename(filename).chomp(File.extname(filename))

output_dir = File.dirname(filename)
output_file = File.join(output_dir, "#{name}.pdf")

temp_dir = '/tmp/latex_refresh'

# Create temp directory if it doesn't already exist
Dir.mkdir(temp_dir) unless File.exists?(temp_dir)

# Set output directory and place aux files in /tmp
options = [
  #"-aux-directory=#{temp_dir}", # This doesn't work for some reason :(
  "-output-directory=#{output_dir}"
]

# The rest of the arguments are options that can be passed into pdflatex
options += ARGV[1..-1] if ARGV.size > 1

# Listen for changes to the tex file
Listen.to(File.dirname(filename), :filter => /\.tex$/) do |modified, added, removed|
  #`pdflatex '#{filename}' #{options.join(' ')} 2>&1 /dev/null`
  `pdflatex '#{filename}' #{options.join(' ')}`

  # If you want to open it with Skim.app us this line
  # Redirect output to /dev/null since Skim.app complains a lot even if it's working
  `open -g '#{output_file}' -a '~/Applications/Skim.app' 2>&1 /dev/null`

  # Preview.app only refreshes the PDF when we give it focus,
  # so we'll use this hack to give it focus and return focus back
  # to the application that was open before.
  # If you want to use a different viewer you can get rid of all this...
  #
  ## Get the currently focused application
  #app = `osascript -e 'POSIX path of (path to application (name of (info for (path to frontmost application))))'`.strip
  #
  ## Open the PDF
  #`open '#{output_file}'`
  #
  ## Restore focus to the original app
  #`osascript -e 'tell application "#{app}" to activate'`
end