PHP清除字符串中空白正则表达式

<?php

trim 去除一个字符串两端空格，
rtrim 是去除一个字符串右部空格，
ltrim 是去除一个字符串左部空格。

echo trim(" 空格 ")."<br>";
echo rtrim(" 空格 ")."<br>";
echo ltrim(" 空格 ")."<br>";

?>

function trimall($str)//删除空格
{
 $qian=array(" ","　","t","n","r");
         $hou=array("","","","","");
 return str_replace($qian,$hou,$str); 
}

$str = " This line containstliberal rn use of whitespace.nn";

// First remove the leading/trailing whitespace
//去掉开始和结束的空白
$str = trim($str);

// Now remove any doubled-up whitespace
//去掉跟随别的挤在一块的空白
$str = preg_replace('/s(?=s)/', '', $str);

// Finally, replace any non-space whitespace, with a space
//最后，去掉非space 的空白，用一个空格代替
$str = preg_replace('/[nrt]/', ' ', $str);

// Echo out: 'This line contains liberal use of whitespace.'
echo "<pre>{$str}</pre>";

<?php
$filename = "中文 文件名.txt";
header('Content-Type: application/octet-stream');
header('Content-Disposition: attachment; filename=' . $filename);
print "Hello!";
?>

<?php
    $file = "/tmp/中文名.tar.gz";

    $filename = basename($file);

    header("Content-type: application/octet-stream");

    //处理中文文件名
    $ua = $_SERVER["HTTP_USER_AGENT"];
    $encoded_filename = urlencode($filename);
    $encoded_filename = str_replace("+", "%20", $encoded_filename);
    if (preg_match("/MSIE/", $ua)) {
     header('Content-Disposition: attachment; filename="' . $encoded_filename . '"');
    } else if (preg_match("/Firefox/", $ua)) {
     header("Content-Disposition: attachment; filename*="utf8''" . $filename . '"');
    } else {
     header('Content-Disposition: attachment; filename="' . $filename . '"');
    }

    header('Content-Disposition: attachment; filename="' . $filename . '"');
    header("Content-Length: ". filesize($file));
    readfile($file);
?>

$finfo    = finfo_open(FILEINFO_MIME);
$mimetype = finfo_file($finfo, $filename);
finfo_close($finfo);

<?php
$mime = array (
  //applications
  'ai'    => 'application/postscript',
  'eps'   => 'application/postscript',
  'exe'   => 'application/octet-stream',
  'doc'   => 'application/vnd.ms-word',
  'xls'   => 'application/vnd.ms-excel',
  'ppt'   => 'application/vnd.ms-powerpoint',
  'pps'   => 'application/vnd.ms-powerpoint',
  'pdf'   => 'application/pdf',
  'xml'   => 'application/xml',
  'odt'   => 'application/vnd.oasis.opendocument.text',
  'swf'   => 'application/x-shockwave-flash',
  // archives
  'gz'    => 'application/x-gzip',
  'tgz'   => 'application/x-gzip',
  'bz'    => 'application/x-bzip2',
  'bz2'   => 'application/x-bzip2',
  'tbz'   => 'application/x-bzip2',
  'zip'   => 'application/zip',
  'rar'   => 'application/x-rar',
  'tar'   => 'application/x-tar',
  '7z'    => 'application/x-7z-compressed',
  // texts
  'txt'   => 'text/plain',
  'php'   => 'text/x-php',
  'html'  => 'text/html',
  'htm'   => 'text/html',
  'js'    => 'text/javascript',
  'css'   => 'text/css',
  'rtf'   => 'text/rtf',
  'rtfd'  => 'text/rtfd',
  'py'    => 'text/x-python',
  'java'  => 'text/x-java-source',
  'rb'    => 'text/x-ruby',
  'sh'    => 'text/x-shellscript',
  'pl'    => 'text/x-perl',
  'sql'   => 'text/x-sql',
  // images
  'bmp'   => 'image/x-ms-bmp',
  'jpg'   => 'image/jpeg',
  'jpeg'  => 'image/jpeg',
  'gif'   => 'image/gif',
  'png'   => 'image/png',
  'tif'   => 'image/tiff',
  'tiff'  => 'image/tiff',
  'tga'   => 'image/x-targa',
  'psd'   => 'image/vnd.adobe.photoshop',
  //audio
  'mp3'   => 'audio/mpeg',
  'mid'   => 'audio/midi',
  'ogg'   => 'audio/ogg',
  'mp4a'  => 'audio/mp4',
  'wav'   => 'audio/wav',
  'wma'   => 'audio/x-ms-wma',
  // video
  'avi'   => 'video/x-msvideo',
  'dv'    => 'video/x-dv',
  'mp4'   => 'video/mp4',
  'mpeg'  => 'video/mpeg',
  'mpg'   => 'video/mpeg',
  'mov'   => 'video/quicktime',
  'wm'    => 'video/x-ms-wmv',
  'flv'   => 'video/x-flv',
  'mkv'   => 'video/x-matroska'
  );

function _getMimeDetect() {
 if (class_exists('finfo')) {
  return 'finfo';
 } else if (function_exists('mime_content_type')) {
  return 'mime_content_type';
 } else if ( function_exists('exec')) {
  $result = exec('file -ib '.escapeshellarg(__FILE__));
  if ( 0 === strpos($result, 'text/x-php') OR 0 === strpos($result, 'text/x-c++')) {
   return 'linux';
  }
  $result = exec('file -Ib '.escapeshellarg(__FILE__));
  if ( 0 === strpos($result, 'text/x-php') OR 0 === strpos($result, 'text/x-c++')) {
   return 'bsd';
  }
 }
 return 'internal';
}

function _getMimeType($path) {
 global $mime;
 $fmime = _getMimeDetect();
 switch($fmime) {
  case 'finfo':
   $finfo = finfo_open(FILEINFO_MIME);
   if ($finfo)
    $type = @finfo_file($finfo, $path);
   break;
  case 'mime_content_type':
   $type = mime_content_type($path);
   break;
  case 'linux':
   $type = exec('file -ib '.escapeshellarg($path));
   break;
  case 'bsd':
   $type = exec('file -Ib '.escapeshellarg($path));
   break;
  default:
   $pinfo = pathinfo($path);
   $ext = isset($pinfo['extension']) ? strtolower($pinfo['extension']) : '';
   $type = isset($mime[$ext]) ? $mime[$ext] : 'unkown';
   break;
 }
 $type = explode(';', $type);
 
 //需要加上这段，因为如果使用mime_content_type函数来获取一个不存在的$path时会返回'application/octet-stream'
 if ($fmime != 'internal' AND $type[0] == 'application/octet-stream') {
  $pinfo = pathinfo($path);
  $ext = isset($pinfo['extension']) ? strtolower($pinfo['extension']) : '';
  if (!empty($ext) AND !empty($mime[$ext])) {
   $type[0] = $mime[$ext];
  }
 }
 
 return $type[0];
}

$path = '1.txt';  //实际上当前路径并不存在1.txt
var_dump(_getMimeType($path));

/*End of php*/

<?php
class BaseClass {
   public function test() {
       echo "BaseClass::test() called＼n";
   }
  
   final public function moreTesting() {
       echo "BaseClass::moreTesting() called＼n";
   }
}

class ChildClass extends BaseClass {
   public function moreTesting() {
       echo "ChildClass::moreTesting() called＼n";
   }
}
// 产生 Fatal error: Cannot override final method BaseClass::moreTesting()
?>
Example #2 Final 类示例

<?php
final class BaseClass {
   public function test() {
       echo "BaseClass::test() called＼n";
   }
  
   // 这里无论你是否将方法声明为final，都没有关系
   final public function moreTesting() {
       echo "BaseClass::moreTesting() called＼n";
   }
}

class ChildClass extends BaseClass {
}
// 产生 Fatal error: Class ChildClass may not inherit from final class (BaseClass)
?>

<?php
function test()
{
    static $var1=1;
    $var1+=2;
    echo $var1.' ';
}

test();
test();
test();
?>

<?php
Class Person{
    // 定义静态成员属性
    public static $country = "中国";
    // 定义静态成员方法
    public static function myCountry() {
        // 内部访问静态成员属性
        echo "我是".self::$country."人<br />";
    }
}
class Student extends Person {
    function study() {
        echo "我是". parent::$country."人<br />";
    }
}
// 输出成员属性值
echo Person::$country."<br />";  // 输出：中国
$p1 = new Person();
//echo $p1->country;   // 错误写法
// 访问静态成员方法
Person::myCountry();   // 输出：我是中国人
// 静态方法也可通过对象访问：
$p1->myCountry();

// 子类中输出成员属性值
echo Student::$country."<br />"; // 输出：中国
$t1 = new Student();
$t1->study();    // 输出：我是中国人
?>

<?php
Class Person{
    // 定义常量
    const country = "中国";

    public function myCountry() {
        //内部访问常量
        echo "我是".self::country."人<br />";
    }
}

// 输出常量
echo Person::country."<br />";

// 访问方法
$p1 = new Person();
$p1 -> myCountry();
?>

<?php
// Declare a simple class
class TestClass
{
    public $foo;

    public function __construct($foo)
    {
        $this->foo = $foo;
    }

    public function __toString() {
        return $this->foo;
    }
}

$class = new TestClass('Hello');
echo $class;
?>

<?php
class SubObject
{
    static $instances = 0;
    public $instance;

    public function __construct() {
        $this->instance = ++self::$instances;
    }

    public function __clone() {
        $this->instance = ++self::$instances;
    }
}

class MyCloneable
{
    public $object1;
    public $object2;

    function __clone()
    {
     
        // 强制复制一份this->object， 否则仍然指向同一个对象
        $this->object1 = clone $this->object1;
    }
}

$obj = new MyCloneable();

$obj->object1 = new SubObject();
$obj->object2 = new SubObject();

$obj2 = clone $obj;

print("Original Object:＼n");
print_r($obj);

print("Cloned Object:＼n");
print_r($obj2);

?>

<?php
session_start();
require_once 'MyClass.php';
$obj = new MyClass;
$_SESSION['obj'] = $obj;
?>

<?php
session_start();
require_once 'MyClass.php';
$_SESSION['obj']->callSomeMethod();
?>

<?php
require_once 'MyClass.php';
session_start();
$_SESSION['obj']->callSomeMethod();
?>

<?php
$filename = '/path/to/foo.txt';

if (file_exists($filename)) {
    print "The file $filename exists";
} else {
    print "The file $filename does not exist";
}
?>

$fp=fopen('aa.txt',   'w+');   //建立一新文件  
chmod('aa.txt',   0777);   //设定权限,不然的话建立后无法修改,删除   //好象这行不用也可以
fwrite($fp,   '要写入的内容');   //写内容  
fclose($fp);   //关闭文件

function dir_clear($dir) {
    $directory = dir($dir);                //创建一个dir类(Php手册上这么说的)，用来读取目录中的每一个文

件
    while($entry = $directory->read()) {   //循环每一个文件,并取得文件名$entry
        $filename = $dir.'/'.$entry;       //取得完整的文件名，带路径的
        if(is_file($filename)) {           //如果是文件，则执行删除操作
            @unlink($filename);
        }
    }
    $directory->close();                   //关闭读取目录文件的类
    result();
}

<?php
/*
 * PHP 读取目录下及其子目下的文件函数
 * */
$files=getFile("images");//调用函数
foreach ($files as $name){
 echo "$name"."<br>";
}
 
function getFile($dir){
 $files=array();
 if (is_file($dir)){//如果指定路径为文件直接返回
  return $dir;
 }
 
 $hande=opendir($dir);
 
 if ($hande){
  while (false!==($ufile=readdir($hande))){//如果读取目录成功
   if ($ufile!="." && $ufile!=".."){
    $filename=$dir."/".$ufile;
    if (is_file($filename)){
     $files[]=$filename;
    }else{
     $files=array_merge($files,getFile($filename));
    }
   }
  }//end While
  closedir($hande);
 }//end if
 
 return $files;
}
?>