some useful php function 2

断点续传

<?php
	function sendfile($myFile){ 
		$mm_type="application/octet-stream"; 
		$fp = fopen($myFile,'rb'); 
		$size = filesize($myFile); 
		ob_start(); 
		header("Cache-Control: public, must-revalidate"); 
		header("Pragma: hack"); 
		header("Content-Type: " . $mm_type); 
		header('Content-Disposition: attachment; filename="'.$fname.'"'); 
		header("Content-Transfer-Encoding: binaryn");  
		if (isset($_SERVER['HTTP_RANGE']) && ($_SERVER['HTTP_RANGE'] != "") && preg_match("/^bytes=([0-9]+)-/i", $_SERVER['HTTP_RANGE'], $match) && ($match[1] < $size)) { 
			$range = $match[1]; 
			fseek($fp, $range); 
			header("HTTP/1.1 206 Partial Content"); 
			//header("Date: " . gmdate("D, d M Y H:i:s") . " GMT"); 
			header("Last-Modified: ".gmdate("D, d M Y H:i:s", filemtime($myFile))." GMT"); 
			header("Accept-Ranges: bytes"); 
			$rangesize = ($size - $range) > 0 ? ($size - $range) : 0; 
			header("Content-Length:".$rangesize); 
			header("Content-Range: bytes ".$range.'-'.($size-1)."/".$size); 
			//header("Connection: close"." ");  
		}else{ 
			header("Content-Length: ".(string)($size)); 
			header("Accept-Ranges: bytes"); 
			$range = 0; 
		}  
		fpassthru($fp); 
		ob_end_flush();  
	}
?>

 裁减图片

<? 
	$FILENAME="test.jpg; 
	// 生成图片的宽度 
	$RESIZEWIDTH=400; 
	// 生成图片的高度 
	$RESIZEHEIGHT=400; 

	function ResizeImage($im,$maxwidth,$maxheight,$name){ 
		$width = imagesx($im); 
		$height = imagesy($im); 
		if(($maxwidth && $width > $maxwidth) || ($maxheight && $height > $maxheight)){ 
			if($maxwidth && $width > $maxwidth){ 
				$widthratio = $maxwidth/$width; 
				$RESIZEWIDTH=true; 
			} 
			if($maxheight && $height > $maxheight){ 
				$heightratio = $maxheight/$height; 
				$RESIZEHEIGHT=true; 
			} 
			if($RESIZEWIDTH && $RESIZEHEIGHT){ 
				if($widthratio < $heightratio){ 
					$ratio = $widthratio; 
				}else{ 
					$ratio = $heightratio; 
				} 
			}elseif($RESIZEWIDTH){ 
				$ratio = $widthratio; 
			}elseif($RESIZEHEIGHT){ 
				$ratio = $heightratio; 
			} 
			$newwidth = $width * $ratio; 
			$newheight = $height * $ratio; 
			if(function_exists("imagecopyresampled")){ 
				$newim = imagecreatetruecolor($newwidth, $newheight); 
				imagecopyresampled($newim, $im, 0, 0, 0, 0, $newwidth, $newheight, $width, $height); 
			}else{ 
				$newim = imagecreate($newwidth, $newheight); 
				imagecopyresized($newim, $im, 0, 0, 0, 0, $newwidth, $newheight, $width, $height); 
			} 
			ImageJpeg ($newim,$name . ".jpg"); 
			ImageDestroy ($newim); 
		}else{ 
			ImageJpeg ($im,$name . ".jpg"); 
		} 
	} 
if($_FILES['image']['size']){ 
	if($_FILES['image']['type'] == "image/pjpeg"){ 
		$im = imagecreatefromjpeg($_FILES['image']['tmp_name']); 
	}elseif($_FILES['image']['type'] == "image/x-png"){ 
		$im = imagecreatefrompng($_FILES['image']['tmp_name']); 
	}elseif($_FILES['image']['type'] == "image/gif"){ 
		$im = imagecreatefromgif($_FILES['image']['tmp_name']); 
	} 
	if($im){ 
		if(file_exists("$FILENAME.jpg")){ 
			unlink("$FILENAME.jpg"); 
		} 
		ResizeImage($im,$RESIZEWIDTH,$RESIZEHEIGHT,$FILENAME); 
		ImageDestroy ($im); 
	} 
} 

 压缩文件

<?php
set_time_limit(0);
class phpzip{
    var $file_count = 0 ;
    var $datastr_len   = 0;
    var $dirstr_len = 0;
    var $filedata = ''; //该变量只被类外部程序访问
    var $gzfilename;
    var $fp;
    var $dirstr='';
    /*
    返回文件的修改时间格式.
    只为本类内部函数调用.
    */
    function unix2dostime($unixtime = 0) {
        $timearray = ($unixtime == 0) ? getdate() : getdate($unixtime);
        if ($timearray['year'] < 1980) {
        $timearray['year']    = 1980;
        $timearray['mon']     = 1;
        $timearray['mday']    = 1;
        $timearray['hours']   = 0;
        $timearray['minutes'] = 0;
        $timearray['seconds'] = 0;
        }
        return (($timearray['year'] - 1980) << 25) | ($timearray['mon'] << 21) | ($timearray['mday'] << 16) |
               ($timearray['hours'] << 11) | ($timearray['minutes'] << 5) | ($timearray['seconds'] >> 1);
    }
    /*
    初始化文件,建立文件目录,
    并返回文件的写入权限.
    */
    function startfile($path = 'faisun.zip'){
       $this->gzfilename=$path;
       $mypathdir=array();
       do{
        $mypathdir[] = $path = dirname($path);
       }while($path != '.');
       @end($mypathdir);
       do{
        $path = @current($mypathdir);
        @mkdir($path);
       }while(@prev($mypathdir));
 
       if($this->fp=@fopen($this->gzfilename,"w")){
        return true;
       }
       return false;
    }
    /*
    添加一个文件到 zip 压缩包中.
    */
    function addfile($data, $name){
        $name     = str_replace('\', '/', $name);
        if(strrchr($name,'/')=='/') return $this->adddir($name);
        $dtime    = dechex($this->unix2dostime());
        $hexdtime = 'x' . $dtime[6] . $dtime[7]
                  . 'x' . $dtime[4] . $dtime[5]
                  . 'x' . $dtime[2] . $dtime[3]
                  . 'x' . $dtime[0] . $dtime[1];
        eval('$hexdtime = "' . $hexdtime . '";');
        $unc_len = strlen($data);
        $crc     = crc32($data);
        $zdata   = gzcompress($data);
        $c_len   = strlen($zdata);
        $zdata   = substr(substr($zdata, 0, strlen($zdata) - 4), 2);
    //新添文件内容格式化:
        $datastr = "x50x4bx03x04";
        $datastr .= "x14x00";            // ver needed to extract
        $datastr .= "x00x00";            // gen purpose bit flag
        $datastr .= "x08x00";            // compression method
        $datastr .= $hexdtime;             // last mod time and date
        $datastr .= pack('v', $crc);             // crc32
        $datastr .= pack('v', $c_len);           // compressed filesize
        $datastr .= pack('v', $unc_len);         // uncompressed filesize
        $datastr .= pack('v', strlen($name));    // length of filename
        $datastr .= pack('v', 0);                // extra field length
        $datastr .= $name;
        $datastr .= $zdata;
        $datastr .= pack('v', $crc);                 // crc32
        $datastr .= pack('v', $c_len);               // compressed filesize
        $datastr .= pack('v', $unc_len);             // uncompressed filesize

    fwrite($this->fp,$datastr); //写入新的文件内容
    $my_datastr_len = strlen($datastr);
    unset($datastr);
 
    //新添文件目录信息
        $dirstr = "x50x4bx01x02";
        $dirstr .= "x00x00";                // version made by
        $dirstr .= "x14x00";                // version needed to extract
        $dirstr .= "x00x00";                // gen purpose bit flag
        $dirstr .= "x08x00";                // compression method
        $dirstr .= $hexdtime;                 // last mod time & date
        $dirstr .= pack('v', $crc);           // crc32
        $dirstr .= pack('v', $c_len);         // compressed filesize
        $dirstr .= pack('v', $unc_len);       // uncompressed filesize
        $dirstr .= pack('v', strlen($name) ); // length of filename
        $dirstr .= pack('v', 0 );             // extra field length
        $dirstr .= pack('v', 0 );             // file comment length
        $dirstr .= pack('v', 0 );             // disk number start
        $dirstr .= pack('v', 0 );             // internal file attributes
        $dirstr .= pack('v', 32 );            // external file attributes - 'archive' bit set
        $dirstr .= pack('v',$this->datastr_len ); // relative offset of local header
        $dirstr .= $name;
    $this->dirstr .= $dirstr; //目录信息
    $this -> file_count ++;
    $this -> dirstr_len += strlen($dirstr);
    $this -> datastr_len += $my_datastr_len;
    }
    function adddir($name){
       $name = str_replace("\", "/", $name);
       $datastr = "x50x4bx03x04x0ax00x00x00x00x00x00x00x00x00";
       $datastr .= pack("v",0).pack("v",0).pack("v",0).pack("v", strlen($name) );
       $datastr .= pack("v", 0 ).$name.pack("v", 0).pack("v", 0).pack("v", 0);
       fwrite($this->fp,$datastr); //写入新的文件内容
       $my_datastr_len = strlen($datastr);
       unset($datastr);
       $dirstr = "x50x4bx01x02x00x00x0ax00x00x00x00x00x00x00x00x00";
       $dirstr .= pack("v",0).pack("v",0).pack("v",0).pack("v", strlen($name) );
       $dirstr .= pack("v", 0 ).pack("v", 0 ).pack("v", 0 ).pack("v", 0 );
       $dirstr .= pack("v", 16 ).pack("v",$this->datastr_len).$name;
       $this->dirstr .= $dirstr; //目录信息
       $this -> file_count ++;
       $this -> dirstr_len += strlen($dirstr);
       $this -> datastr_len += $my_datastr_len;
    }
    function createfile(){
       //压缩包结束信息,包括文件总数,目录信息读取指针位置等信息
       $endstr = "x50x4bx05x06x00x00x00x00" .
          pack('v', $this -> file_count) .
          pack('v', $this -> file_count) .
          pack('v', $this -> dirstr_len) .
          pack('v', $this -> datastr_len) .
          "x00x00";
       fwrite($this->fp,$this->dirstr.$endstr);
       fclose($this->fp);
    }
}
?>