How to modify User-Agent in Mechanize and Net::HTTP

User-Agent_setting

# Mechanize http://d.hatena.ne.jp/takuya_1st/20120301/1330605502
mech = Mechanize.new
mech.user_agent_alias = 'Windows IE 7’ #キーを指定。 

AGENT_ALIASES = {
 'Windows IE 6' => 'Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1)',
 'Windows IE 7' => 'Mozilla/4.0 (compatible; MSIE 7.0; Windows NT 5.1; .NET CLR 1.1.4322; .NET CLR 2.0.50727)',
 'Windows Mozilla' => 'Mozilla/5.0 (Windows; U; Windows NT 5.0; en-US; rv:1.4b) Gecko/20030516 Mozilla Firebird/0.6',
 'Mac Safari' => 'Mozilla/5.0 (Macintosh; U; Intel Mac OS X 10_6_2; de-at) AppleWebKit/531.21.8 (KHTML, like Gecko) Version/4.0.4 Safari/531.21.10',
 'Mac FireFox' => 'Mozilla/5.0 (Macintosh; U; Intel Mac OS X 10.6; en-US; rv:1.9.2) Gecko/20100115 Firefox/3.6',
 'Mac Mozilla' => 'Mozilla/5.0 (Macintosh; U; PPC Mac OS X Mach-O; en-US; rv:1.4a) Gecko/20030401',
 'Linux Mozilla' => 'Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.4) Gecko/20030624',
 'Linux Firefox' => 'Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.9.2.1) Gecko/20100122 firefox/3.6.1',
 'Linux Konqueror' => 'Mozilla/5.0 (compatible; Konqueror/3; Linux)',
 'iPhone' => 'Mozilla/5.0 (iPhone; U; CPU like Mac OS X; en) AppleWebKit/420+ (KHTML, like Gecko) Version/3.0 Mobile/1C28 Safari/419.3',
 'Mechanize' => "WWW-Mechanize/#{VERSION} (http://rubyforge.org/projects/mechanize/)"
}


# net/http  http://blog.cles.jp/item/3367

require 'net/http'
Net::HTTP.version_1_2
USER_AGENT= "TestAgent"

Net::HTTP.start('127.0.0.1', 80) {|http|
  response = http.get('/')
  response = http.get('/', 'User-Agent' => USER_AGENT )
}

> 127.0.0.1 - - [05/Jan/2010:21:26:31 +0900] "GET / HTTP/1.1" 200 2343 "-" "-"
> 127.0.0.1 - - [05/Jan/2010:21:26:31 +0900] "GET / HTTP/1.1" 200 2343 "-" "TestAgent"