download

#!/usr/bin/env ruby
# Download a file:
#   download http://fake.com/file.zip
#
# Download multiple files:
#   download http://fake.com/file1.zip http://fake.com/file2.zip
#
# Download file(s) to a directory:
#   download http://fake.com/file.zip /tmp/
#   download http://fake.com/file1.zip http://fake.com/file2.zip .

require 'uri'

# Checks if a path looks like a URL.
def is_url?( path )
  path =~ URI::ABS_URI
end

# Checks if a path is a valid directory.
def is_directory?( path )
  path = File.expand_path( path )
  File.directory?( path )
end

# Collect URLs from the command line.
urls = []
ARGV.each { |arg| urls.push( arg ) if is_url?( arg ) }

# Set download directory. Default to '~/Downloads' if one is not specified.
directory = "#{ENV['HOME']}/Downloads"
directory = ARGV.last if is_directory?( ARGV.last )

# Build the command.
command = 'curl --continue-at - --location'
urls.each { |url| command << " --remote-name '#{url}'" }

# Change to the download directory and execute command.
Dir.chdir( directory ) do
  system command
end