PHP实用代码片段（三）

1. 目录清单

使用下面的 PHP 代码片段可以在一个目录中列出所有文件和文件夹。

function list_files($dir)
{
    if(is_dir($dir))
    {
        if($handle = opendir($dir))
        {
            while(($file = readdir($handle)) !== false)
            {
                if($file != "." && $file != ".." && $file != "Thumbs.db"/*pesky windows, images..*/)
                {
                    echo '<a target="_blank" href="'.$dir.$file.'">'.$file.'</a><br>'."\n";
                }
            }
            closedir($handle);
        }
    }
}

语法：

<?php
    list_files("images/"); //This will list all files of images folder
?>

2. 检测用户语言

使用下面的 PHP 代码片段可以检测用户浏览器所使用的语言。

function get_client_language($availableLanguages, $default='en'){
    if (isset($_SERVER['HTTP_ACCEPT_LANGUAGE'])) {
        $langs=explode(',',$_SERVER['HTTP_ACCEPT_LANGUAGE']);
        foreach ($langs as $value){
            $choice=substr($value,0,2);
            if(in_array($choice, $availableLanguages)){
                return $choice;
            }
        }
    }
    return $default;
}

3. 查看 CSV 文件

function readCSV($csvFile){
    $file_handle = fopen($csvFile, 'r');
    while (!feof($file_handle) ) {
        $line_of_text[] = fgetcsv($file_handle, 1024);
    }
    fclose($file_handle);
    return $line_of_text;
}

语法：

<?php
$csvFile = "test.csv";
$csv = readCSV($csvFile);
$a = csv[0][0]; // This will get value of Column 1 & Row 1
?>

4. 从 PHP 数据创建 CSV 文件

function generateCsv($data, $delimiter = ',', $enclosure = '"') {
   $handle = fopen('php://temp', 'r+');
   foreach ($data as $line) {
           fputcsv($handle, $line, $delimiter, $enclosure);
   }
   rewind($handle);
   while (!feof($handle)) {
           $contents .= fread($handle, 8192);
   }
   fclose($handle);
   return $contents;
}

语法：

<?php
$data[0] = "apple";
$data[1] = "oranges";
generateCsv($data, $delimiter = ',', $enclosure = '"');
?>

5. 解析 XML 数据

$xml_string="<?xml version='1.0'?>
<moleculedb>
    <molecule name='Benzine'>
        <symbol>ben</symbol>
        <code>A</code>
    </molecule>
    <molecule name='Water'>
        <symbol>h2o</symbol>
        <code>K</code>
    </molecule>
</moleculedb>";

//load the xml string using simplexml function
$xml = simplexml_load_string($xml_string);

//loop through the each node of molecule
foreach ($xml->molecule as $record)
{
   //attribute are accessted by
   echo $record['name'], '  ';
   //node are accessted by -> operator
   echo $record->symbol, '  ';
   echo $record->code, '<br />';
}

6. 解析 JSON 数据

$json_string='{"id":1,"name":"rolf","country":"russia","office":["google","oracle"]} ';
$obj=json_decode($json_string);
//print the parsed data
echo $obj->name; //displays rolf
echo $obj->office[0]; //displays google

7. 获取当前页面 URL

这个 PHP 片段可以帮助你让用户登录后直接跳转到之前浏览的页面。

function current_url()
{
$url = "http://" . $_SERVER['HTTP_HOST'] . $_SERVER['REQUEST_URI'];
$validURL = str_replace("&", "&", $url);
return validURL;
}

语法：

<?php
echo "Currently you are on: ".current_url();
?>

8. 从任意的 Twitter 账号获取最新的 Tweet

function my_twitter($username)
{
     $no_of_tweets = 1;
     $feed = "http://search.twitter.com/search.atom?q=from:" . $username . "&rpp=" . $no_of_tweets;
     $xml = simplexml_load_file($feed);
    foreach($xml->children() as $child) {
        foreach ($child as $value) {
            if($value->getName() == "link") $link = $value['href'];
            if($value->getName() == "content") {
                $content = $value . "";
        echo '<p class="twit">'.$content.' <a class="twt" href="'.$link.'" title="">&nbsp; </a></p>';
            }
        }
    }
}

语法：

<?php
$handle = "koonktech";
my_twitter($handle);
?>

9. 转发数量

使用这个 PHP 片段可以检测你的页面 URL 有多少转发数量。

function tweetCount($url) {
    $content = file_get_contents("http://api.tweetmeme.com/url_info?url=".$url);
    $element = new SimpleXmlElement($content);
    $retweets = $element->story->url_count;
    if($retweets){
        return $retweets;
    } else {
        return 0;
    }
}

语法：

<?php
$url = "http://blog.koonk.com";
$count = tweetCount($url);
return $count;
?>

10. 计算两个日期的差

<?php
$date1 = date( 'Y-m-d' );
$date2 = "2015-12-04";
$diff = abs(strtotime($date2) - strtotime($date1));
$years = floor($diff / (365*60*60*24));
$months = floor(($diff - $years * 365*60*60*24) / (30*60*60*24));
$days = floor(($diff - $years * 365*60*60*24 - $months*30*60*60*24)/ (60*60*24));
printf("%d years, %d months, %d days\n", $years, $months, $days);
-------------------------------------------------------- OR
$date1 = new DateTime("2007-03-24");
$date2 = new DateTime("2009-06-26");
$interval = $date1->diff($date2);
echo "difference " . $interval->y . " years, " . $interval->m." months, ".$interval->d." days ";
// shows the total amount of days (not divided into years, months and days like above)
echo "difference " . $interval->days . " days ";
-------------------------------------------------------- OR

/**
 * Calculate differences between two dates with precise semantics. Based on PHPs DateTime::diff()
 * implementation by Derick Rethans. Ported to PHP by Emil H, 2011-05-02. No rights reserved.
 *
 * See here for original code:
 * http://svn.php.net/viewvc/php/php-src/trunk/ext/date/lib/tm2unixtime.c?revision=302890&view=markup
 * http://svn.php.net/viewvc/php/php-src/trunk/ext/date/lib/interval.c?revision=298973&view=markup
 */
function _date_range_limit($start, $end, $adj, $a, $b, $result)
{
    if ($result[$a] < $start) {
        $result[$b] -= intval(($start - $result[$a] - 1) / $adj) + 1;
        $result[$a] += $adj * intval(($start - $result[$a] - 1) / $adj + 1);
    }
    if ($result[$a] >= $end) {
        $result[$b] += intval($result[$a] / $adj);
        $result[$a] -= $adj * intval($result[$a] / $adj);
    }
    return $result;
}
function _date_range_limit_days($base, $result)
{
    $days_in_month_leap = array(31, 31, 29, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31);
    $days_in_month = array(31, 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31);
    _date_range_limit(1, 13, 12, "m", "y", &$base);
    $year = $base["y"];
    $month = $base["m"];
    if (!$result["invert"]) {
        while ($result["d"] < 0) {
            $month--;
            if ($month < 1) {
                $month += 12;
                $year--;
            }
            $leapyear = $year % 400 == 0 || ($year % 100 != 0 && $year % 4 == 0);
            $days = $leapyear ? $days_in_month_leap[$month] : $days_in_month[$month];
            $result["d"] += $days;
            $result["m"]--;
        }
    } else {
        while ($result["d"] < 0) {
            $leapyear = $year % 400 == 0 || ($year % 100 != 0 && $year % 4 == 0);
            $days = $leapyear ? $days_in_month_leap[$month] : $days_in_month[$month];
            $result["d"] += $days;
            $result["m"]--;
            $month++;
            if ($month > 12) {
                $month -= 12;
                $year++;
            }
        }
    }
    return $result;
}
function _date_normalize($base, $result)
{
    $result = _date_range_limit(0, 60, 60, "s", "i", $result);
    $result = _date_range_limit(0, 60, 60, "i", "h", $result);
    $result = _date_range_limit(0, 24, 24, "h", "d", $result);
    $result = _date_range_limit(0, 12, 12, "m", "y", $result);
    $result = _date_range_limit_days(&$base, &$result);
    $result = _date_range_limit(0, 12, 12, "m", "y", $result);
    return $result;
}
/**
 * Accepts two unix timestamps.
 */
function _date_diff($one, $two)
{
    $invert = false;
    if ($one > $two) {
        list($one, $two) = array($two, $one);
        $invert = true;
    }
    $key = array("y", "m", "d", "h", "i", "s");
    $a = array_combine($key, array_map("intval", explode(" ", date("Y m d H i s", $one))));
    $b = array_combine($key, array_map("intval", explode(" ", date("Y m d H i s", $two))));
    $result = array();
    $result["y"] = $b["y"] - $a["y"];
    $result["m"] = $b["m"] - $a["m"];
    $result["d"] = $b["d"] - $a["d"];
    $result["h"] = $b["h"] - $a["h"];
    $result["i"] = $b["i"] - $a["i"];
    $result["s"] = $b["s"] - $a["s"];
    $result["invert"] = $invert ? 1 : 0;
    $result["days"] = intval(abs(($one - $two)/86400));
    if ($invert) {
        _date_normalize(&$a, &$result);
    } else {
        _date_normalize(&$b, &$result);
    }
    return $result;
}
$date = "2014-12-04 19:37:22";
echo '<pre>';
print_r( _date_diff( strtotime($date), time() ) );
echo '</pre>';
?>