PHP中preg_match_all函数正则匹配详解

<?php
preg_match_all("|<[^>]+>(.*)</[^>]+>|U",
    "<b>example: </b><div align=left>this is a test</div>",
    $out, PREG_PATTERN_ORDER);
echo $out[0][0] . ", " . $out[0][1] . "n";
echo $out[1][0] . ", " . $out[1][1] . "n";
?>

$get = 'd1b3cid419299191rs好脚本';
$rs_pos = strpos($get,'rs');
if($rs_pos !== false)
{
    $rs = substr($get,$rs_pos);
    $rs = str_replace('rs','',$rs);
    $rs = strpos($rs,'/')!==false ? substr($rs,0,strpos($rs,'/')) : $rs;
    $get = substr($get,0,$rs_pos);
}
echo 'keywords='.$rs;
echo '<br>';
preg_match_all('/([a-z]*)([0-9]+)/',$get,$m);
if($m)
{
        $k = $v = '';
        $count = count($m[1]);
        for($i = 0; $i <= $count; $i++)
        {
            ${$m[1][$i]} = $m[2][$i];
            if(isset(${$m[1][$i]}))
            {   
                echo $m[1][$i].'='.${$m[1][$i]};
                echo '<br>';
            }
        }
}

<?php
$con = file_get_contents("http://www.111cn.net/");
$pattern="/<[img|IMG].*?src=['|"](.*?(?:[.gif|.jpg|.png]))['|"].*?[/]?>/";
preg_match_all($pattern,$con,$match);
print_r($match);
?>

输出代码

Array
(
[0] => Array
(
[0] => <img src="http://www.111cn.net/usr/themes/dddefault/images/logo.png" alt="" />
[1] => <img style="display: block; margin-left: auto; margin-right: auto;" title="" src="http://www.111cn.net/usr/uploads/2012/09/531656480.jpg" alt="2" />
[2] => <img style="display: block; margin-left: auto; margin-right: auto;" src="http://www.111cn.net/usr/uploads/2012/09/2647136297.jpg" alt="875EA1C00E50B4542797E24FA6E7E1F2.jpg" />
)
[1] => Array
(
[0] => http://www.111cn.net/usr/themes/dddefault/images/logo.png
[1] => http://www.111cn.net/usr/uploads/2012/09/531656480.jpg
[2] => http://www.111cn.net/usr/uploads/2012/09/2647136297.jpg
)
)

1 echo date('Y-m-d H:i:s',strtotime('now')+8*60*60);
结果:2013-04-05 03:15:02

1 echo date('Y-m-d H:i:s',time()+8*60*60);
结果:2013-04-05 03:15:02

1 echo date('Y-m-d H:i:s',strtotime("+10 days")+8*60*60);

1 strtotime("+1 week")+8*60*60

strtotime("+7 days");

1 strtotime ("+1 week 2 days 4 hours 2 seconds")+8*60*60
1 echo date('Y-m-d H:i:s',strtotime ("+1 week 2 days 4 hours 2 seconds")+8*60*60);

1 strtotime ("last Monday")+8*60*60
1 echo date('Y-m-d H:i:s',strtotime ("last Monday")+8*60*60);

1 strtotime ("next Thursday")+8*60*60
1 echo date('Y-m-d H:i:s',strtotime ("next Thursday")+8*60*60);

<?php
$time="2012年11月23日15时50时20秒";
$times="2013-01-14 09:09:09";
if(strtotime($time)-strtotime($times)<0){
 echo "时间：".$time."&nbsp;早于时间：".$times;
}else{
 echo "时间：".$times."&nbsp;早于时间：".$time;
}
echo "<br />它们相差的时间值是：".(strtotime($time)-strtotime($times))
?>

< ?php
$file_contents = file_get_contents(''http://www.111cn.net/'');
echo $file_contents;
?>

function file_get_content($url) {
if (function_exists(‘file_get_contents')) {
$file_contents = @file_get_contents($url);
}
if ($file_contents == ”) {
$ch = curl_init();
$timeout = 30;
curl_setopt($ch, CURLOPT_URL, $url);
curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);
curl_setopt($ch, CURLOPT_CONNECTTIMEOUT, $timeout);
$file_contents = curl_exec($ch);
curl_close($ch);
}
return $file_contents;
}

<?php
$a = "alsdflasdf;a";
$b = var_dump($a);
echo "<br>";
//var_dump($c);
$d=var_dump($c);
echo "<br>";
echo $a;
echo "<br>";
echo $b;
echo "<br>";
输出：
string(12) "alsdflasdf;a"
NULL
alsdflasdf;a

<pre>
<?php
$a = array (1, 2, array ("a", "b", "c"));
var_dump ($a);

/* 输出：
array(3) {
  [0]=>
  int(1)
  [1]=>
  int(2)
  [2]=>
  array(3) {
    [0]=>
    string(1) "a"
    [1]=>
    string(1) "b"
    [2]=>
    string(1) "c"
  }
}

*/

$b = 3.1;
$c = TRUE;
var_dump($b,$c);

/* 输出：
float(3.1)
bool(true)

*/
?>
</pre> 

<?
set_time_limit(50);
$a = array(1,2,3);
$b = array('a'=>1, 'b'=>2, 'c'=>3);
$c = array('a'=>array(1,2,3), 'b'=>array(4,5,6));

$time1 = microtime(true);

$times = 1000000; #10w

for($i=1; $i<=$times; $i++){
 $A = var_export($a, true);
}

$time2 = microtime(true);

for($i=1; $i<=$times; $i++){
 $B = var_export($b, true);
}

$time3 = microtime(true);

for($i=1; $i<=$times; $i++){
 $C = var_export($c, true);
}

$time4 = microtime(true);

for($i=1; $i<=$times; $i++){
 $X = serialize($a);
}

$time5 = microtime(true);

for($i=1; $i<=$times; $i++){
 $Y = serialize($b);
}

$time6 = microtime(true);

for($i=1; $i<=$times; $i++){
 $Z = serialize($c);
}

$time7 = microtime(true);

for($i=1; $i<=$times; $i++){
 $O = unserialize($X);
}

$time8 = microtime(true);

for($i=1; $i<=$times; $i++){
 $P = unserialize($Y);
}

$time9 = microtime(true);

for($i=1; $i<=$times; $i++){
 $Q = unserialize($Z);
}
$time10 = microtime(true);

$var_export_time['a'] = $time2 - $time1;
$var_export_time['b'] = $time3 - $time2;
$var_export_time['c'] = $time4 - $time3;

$serialize_time['a'] = $time5 - $time4;
$serialize_time['b'] = $time6 - $time5;
$serialize_time['c'] = $time7 - $time6;

$unserialize_time['a'] = $time8 - $time7;
$unserialize_time['b'] = $time9 - $time8;
$unserialize_time['c'] = $time10 - $time9;
print_r($var_export_time);
print_r($serialize_time);
print_r($unserialize_time);
?>
output:
Array(    [a] => 3.3401498794556    [b] => 5.1394801139832    [c] => 8.8483898639679)Array(    [a] => 1.6063709259033    [b] => 1.7033960819244    [c] => 3.4534389972687)Array(    [a] => 1.6037359237671    [b] => 1.817803144455    [c] => 3.7992968559265)

<?php
echo dirname("c:/testweb/home.php");
echo dirname("/testweb/home.php");
?>

输出：

c:/testweb
/testweb

<?php
$basedir = dirname(__FILE__);
echo $basedir
//将在页面打印出一个这个文件所在绝对路径!
?>