php 正则表达式(Regular Expression)用法

function GetAllLink($string)
{
$string = str_replace("r","",$string);
$string = str_replace("n","",$string);

$regex[url] = "((http|https|ftp|telnet|news)://)?([a-z0-9_-/.]+.[][a-z0-9:;&#@=_~%?/.,+-]+)";
$regex[email] = "([a-z0-9_-]+)@([a-z0-9_-]+.[a-z0-9-._-]+)";

//去掉标签之间的文字
$string = eregi_replace(">[^<>]+<","><", $string);

//去掉JAVASCRIPT代码
$string = eregi_replace("<!--.*//-->","", $string);

$string = eregi_replace("<[^a][^<>]*>","", $string);

//去掉EMAIL链接
$string = eregi_replace("<a([ ]+)href=(["']*)mailto:($regex[email])(["']*)[^>]*>","", $string);

//替换需要的网页链接
$string = eregi_replace("<a([ ]+)href=(["']*)($regex[url])(["']*)[^>]*>","\3t", $string);

$output[0] = strtok($string, "t");
while(($temp = strtok("t")))
{
if($temp && !in_array($temp, $output))
$output[++$i] = $temp;
}

return $output;
}

<?php
$str = 'a1234';
if (preg_match("^[a-zA-Z0-9]{4,16}$", $str)) {
echo "验证成功";} else {
echo "验证失??quot;;}?>

<?php
$str = 'a1234';
if (preg_match("^(?:d{15}|d{18})$", $str)) {
echo "验证成功";
} else {
echo "验证失??quot;;}
?>

function codedisp($code) {
global $discuzcodes;
$discuzcodes['pcodecount']++;
$code = htmlspecialchars(str_replace('\"', '"', preg_replace("/^[nr]*(.+?)[nr]*$/is", "\1", $code)));
$discuzcodes['codehtml'][$discuzcodes['pcodecount']] = "<br><div class="msgheader"><div class="right"><a href="###" class="smalltxt" onclick="copycode($('phpcode$discuzcodes[codecount]'));">[复制此代码]</a></div>代码如下:</div><div class="msgborder" id="phpcode$discuzcodes[codecount]">".fhtml2($code)."</div><br>";
$discuzcodes['codecount']++;
return "[tDISCUZ_CODE_$discuzcodes[pcodecount]t]";
}
$message = preg_replace("/s*[code](.+?)[/code]s*/ies", "codedisp('\1')", $message);
$message = preg_replace("/s*[html](.+?)[/html]s*/ies", "htmldisp('\1')", $message);

<?php
$file = "test.txt";
if(is_readable($file))
  {
  echo ("$file is readable");
  }
else
  {
  echo ("$file is not readable");
  }
?>

<?php

　　$file = "filelist.php";

　　if (file_exists($file) == false) {

　　die('文件不存在');

}

$data = file_get_contents($file);

echo htmlentities($data);

?>

function vita_get_url_content($url) {
if(function_exists('file_get_contents')) {
$file_contents = file_get_contents($url);
} else {
$ch = curl_init();
$timeout = 5;
curl_setopt ($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;
}

$filename = "/www.111cn.net/local/something.txt";
$handle = fopen($filename, "r");
$contents = fread($handle, filesize($filename));
fclose($handle);

$handle = fopen("http://www.111cn.net/", "rb");
$contents = stream_get_contents($handle);
fclose($handle);

$data = implode('', file($file));

$fp = fsockopen ("192.168.0.128", 80, $errno, $errstr, 30);
if (!$fp) {
echo "$errstr ($errno)<br>n";
} else {
$msg="GET /003.php HTTP/1.0rn";
$msg.="Host: 192.168.0.128rn";
$msg.="Referer: http://www.baidu.comrn";

$msg.="Client-IP: 1.1.1.1rn";
$msg.="X-Forwarded-For: 1.1.1.1rn"; //主要是这里来构造IP
$msg.="Connection: Closernrn";
fputs ($fp, $msg);
while (!feof($fp)) {
echo fgets ($fp,1024);
}
fclose ($fp);
}

$arr = array();                                           
$arr['a'] = 1;                                              
$arr['b'] = 2;                                              
$arr['c'] = 3;                                              

$arr = array();                                          
$arr['a'] = 1;                                             
$arr['b'] = 2;                                             
$arr['c'] = 3;                                             

$object   = new StdClass;                         
$object->a = 1;                                         
$object->b = 2;                                         
$object->c = 3;                                         

$object   = new StdClass;                          
$object->a = 1;                                          
$object->b = 2;                                          
$object->c = 3;                                           

function object_to_array($obj)
{
$_arr = is_object($obj) ? get_object_vars($obj) : $obj;
foreach ($_arr as $key => $val)
{
$val = (is_array($val) || is_object($val)) ? object_to_array($val) : $val;
$arr[$key] = $val;
}
return $arr;
}

<?php
$array = array(1 => php, 
           2 => java, 
           3 => c ); 

$arrayobject = new ArrayObject($array); 

var_dump($arrayobject); 
?>