Pretty generic project watcher for developing locally, and verifying compilation/tests on a remote server (made for UCSD CSE124)

project_watcher.rb

# dependencies: 
#gem install filewatcher
#gem install childprocess
#gem install net-sftp

# usage: ruby project_watcher.rb <user>@<server> <project or hw folder>
# e.g.   ruby project_watcher.rb cse124XYZ@ieng6.ucsd.edu project1/

# you probably want to add the following to your .gitignore 
# as well: 
# *.o-*
# *.obj
# *.dSYM
# *.dSYM/*
# /httpd

require 'filewatcher'
require 'childprocess'
require 'net/sftp'

folder = ARGV[1]
if folder && File.exist?(folder)
  if folder[-1] == '/'
    folder = folder[0...-1]
  end
  puts "watching folder #{folder}"
else
  puts "folder #{folder} does not exist!"
  puts "usage: watcher.rb <user> <folder>"
  exit 1
end

server = if ARGV[0]
           ARGV[0]
         else
           puts "no user specified"
           puts "usage: watcher.rb <user> <folder>"
           exit 1
         end

ignore_file = File.join(folder, '.gitignore')
ignores = if File.exist?(ignore_file)
            File.read(ignore_file).split("\n").map(&:strip).reject {|i| 
              i[0] == '#' || i.empty?
            }
          else
            []
          end
puts "ignore list: #{ignores.join(", ")}"

user, host = server.split("@")
sftp_conn = begin 
              puts "connect -> #{host} (#{user})"
              Net::SFTP.start(host, user)
            end

# hush announcement (screws up bash login shell with no tty)
# `rm ~/.hushlogin` to get announcement back
puts `ssh #{server} touch ~#{user}/.hushlogin`

# initial rsync to verify both sides are the same
begin
  rs = ChildProcess.build("rsync", "-avP", folder, server)
  rs.io.inherit!
  rs.start
  rs.wait
end

FileWatcher.new(folder).watch do |filename|
  puts "#{filename} changed"

  filename_nofolder = filename[folder.length..-1]
  if i = ignores.find { |i| 
    # puts "#{i} -> #{filename_nofolder} "; 
    File.fnmatch(i, filename_nofolder)
  }
    puts "ignoring #{filename} (#{i})"
    next
  end

  path = filename
  puts "upload #{path} -> #{server}:#{path}"
  sftp_conn.upload!(path, path)

  cp = ChildProcess.build("ssh", server, "sh", "--login", "-c", "'make -C #{folder}'")
  cp.io.inherit!
  cp.start
  cp.wait
end