How to take screenshot and save using phantomjs

<code>var page = require('webpage').create();
var address = 'http://baidu.com';//填写需要打印的文件位置
var output = './img/'+'xigua'+'.png';//存储文件路径和名称
page.viewportSize = { width: 100, height: 100 };//设置长宽
page.open(address, function (status) {
    if (status !== 'success') {
        console.log('Unable to load the address!');
        phantom.exit();
    } else {
        window.setTimeout(function () {
            page.render(output);
            phantom.exit();
        }, 500);
    }
});
</code>

<code><?php
$command = 'phantomjs '.'phantomjs\123.js'; //上面提到的js文件的路径
exec($command,$out);
</code>

<code>var page = require('webpage').create();
var address = 'http://baidu.com';//填写需要打印的文件位置
var output = './img/'+'xigua'+'.png';//存储文件路径和名称
page.viewportSize = { width: 100, height: 100 };//设置长宽
page.open(address, function (status) {
    if (status !== 'success') {
        console.log('Unable to load the address!');
        phantom.exit();
    } else {
        window.setTimeout(function () {
            page.render(output);
            phantom.exit();
        }, 500);
    }
});
</code>

<code><?php
$command = 'phantomjs '.'phantomjs\123.js'; //上面提到的js文件的路径
exec($command,$out);
</code>