XML operation using javascript E4X from Rhino javascript shell

Firstly, download Rhino and install it. Here is a tutorial.
Then, run below command line:

$> java org.mozilla.javascript.tools.shell.Main
Rhino 1.7 release 1 2008 03 06
js> var user = <user id="1"><name type="firstname">Yu</name><name type="lastname">test</name><country>zh_CN</country></user>;
js> user
<user id="1">
<name type="firstname">Yu</name>
<name type="lastname">test</name>
<country>zh_CN</country>
</user>
js> typeof a
undefined
js> typeof user
xml
js> user.name
<name type="firstname">Yu</name>
<name type="lastname">test</name>
js> user.country
zh_CN
js> user.id

js> user.@id
1
js> user.@id = 100
100
js> user
<user id="100">
<name type="firstname">Yu</name>
<name type="lastname">test</name>
<country>zh_CN</country>
</user>
js> user.name[0]
Yu
js> user.name += <name type="nickname">_test</name>;
<name type="firstname">Yu</name>
<name type="lastname">test</name>
<name type="nickname">_test</name>
js> user
<user id="100">
<name type="firstname">Yu</name>
<name type="lastname">test</name>
<name type="nickname">_test</name>
<country>zh_CN</country>
</user>
js> user.name[1]
test
js> user.name[1].@type
lastname
js> for each(var n in user.name) print("The " + n.@type + " name is " + n);
The firstname name is Yu
The lastname name is test
The nickname name is _test
js> for each(var n in user..name) print("The " + n.@type + " name is " + n);
The firstname name is Yu
The lastname name is test
The nickname name is _test
js> quit();

The user..name selector just like the "//" operator in XPath.

$> cat echo.js
for (i in arguments) {
print(arguments[i])
}

$> java org.mozilla.javascript.tools.shell.Main echo.js test yu from google
test
yu
from
google

Reference:
http://developer.mozilla.org/en/Rhino_Shell