无意在网络上发现的PHP在线文件压缩类，可以把文件打包压缩成ZIp压缩包格式，可用于网站文件备份，类中定义了如何下载文件。本压缩类无需其它PHP辅助插件，完全PHP代码实现，使用方便。下面是具体的PHP压缩类代码：
<?php
class PHPZip{
var $dirInfo = array("0","0");
var $rootDir = '';
var $datasec = array();
var $ctrl_dir = array();
var $eof_ctrl_dir = "\x50\x4b\x05\x06\x00\x00\x00\x00";
var $old_offset = 0;
function downloadZip(){
createZip($dir, $zipfilename, true);
}
function createZip($dir, $zipfilename, $autoDownload = false){
if (@function_exists('gzcompress')){
@set_time_limit("0");
if (is_array($dir)){
$fd = fopen ($dir, "r");
$fileValue = fread ($fd, filesize ($filename));
fclose ($fd);
if (is_array($dir)) $filename = basename($dir);
$this -> addFile($fileValue, "$filename");
}else{
$this->dirTree($dir,$dir);
}
$zipfilenametemp = time().$zipfilename;
$out = $this -> filezip();
$fp = fopen($zipfilenametemp, "w");
fwrite($fp, $out, strlen($out));
fclose($fp);
$filesize = filesize($zipfilenametemp);
if ($filesize < 104857600) {
if($autoDownload){
header("Content-type: application/octet-stream");
header("Content-disposition: attachment; filename=".$zipfilename);
}
echo $this -> filezip();
}else{
echo "create zip error!";
}
unlink($zipfilenametemp);
}
}
//get dir tree..
function dirTree($directory,$rootDir){
global $_SERVER,$dirInfo,$rootDir;
$fileDir=$rootDir;
$myDir=dir($directory);
while($file=$myDir->read()){
if(is_dir("$directory/$file") and $file!="." and $file!=".."){
$dirInfo[0]++;
$rootDir ="$fileDir$file/";
$this -> addFile('', "$rootDir");
//go on n's folders
$this->dirTree("$directory/$file",$rootDir);
}else{
if($file!="." and $file!=".."){
$dirInfo[1]++;
//$fd = fopen ("$directory/$file", "r");
$fileValue = file_get_contents("$directory/$file");
//fclose ($fd);
$this -> addFile($fileValue, "$fileDir$file");
}
}
}
$myDir->close();
}
function unix2DosTime($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;
$timearray['seconds'] = 0;
} // end if
return (($timearray['year'] - 1980) << 25) | ($timearray['mon'] << 21) | ($timearray['mday'] << 16) |
($timearray['hours'] << 11) | ($timearray['minutes'] << 5) | ($timearray['seconds'] >> 1);
}
function addFile($data, $name, $time = 0){
$name = str_replace('\\', '/', $name);
$dtime = dechex($this->unix2DosTime($time));
$hexdtime = '\x' . $dtime[6] . $dtime[7]
. '\x' . $dtime[4] . $dtime[5]
. '\x' . $dtime[2] . $dtime[3]
. '\x' . $dtime[0] . $dtime[1];
eval('$hexdtime = "' . $hexdtime . '";');
$fr = "\x50\x4b\x03\x04";
$fr .= "\x14\x00"; // ver needed to extract
$fr .= "\x00\x00"; // gen purpose bit flag
$fr .= "\x08\x00"; // compression method
$fr .= $hexdtime; // last mod time and date
// "local file header" segment
$unc_len = strlen($data);
$crc = crc32($data);
$zdata = gzcompress($data);
$c_len = strlen($zdata);
$zdata = substr(substr($zdata, 0, strlen($zdata) - 4), 2); // fix crc bug
$fr .= pack('V', $crc); // crc32
$fr .= pack('V', $c_len); // compressed filesize
$fr .= pack('V', $unc_len); // uncompressed filesize
$fr .= pack('v', strlen($name)); // length of filename
$fr .= pack('v', 0); // extra field length
$fr .= $name;
// "file data" segment
$fr .= $zdata;
// "data descriptor" segment (optional but necessary if archive is not
// served as file)
$fr .= pack('V', $crc); // crc32
$fr .= pack('V', $c_len); // compressed filesize
$fr .= pack('V', $unc_len); // uncompressed filesize
// add this entry to array
$this -> datasec[] = $fr;
$new_offset = strlen(implode('', $this->datasec));
// now add to central directory record
$cdrec = "\x50\x4b\x01\x02";
$cdrec .= "\x00\x00"; // version made by
$cdrec .= "\x14\x00"; // version needed to extract
$cdrec .= "\x00\x00"; // gen purpose bit flag
$cdrec .= "\x08\x00"; // compression method
$cdrec .= $hexdtime; // last mod time & date
$cdrec .= pack('V', $crc); // crc32
$cdrec .= pack('V', $c_len); // compressed filesize
$cdrec .= pack('V', $unc_len); // uncompressed filesize
$cdrec .= pack('v', strlen($name) ); // length of filename
$cdrec .= pack('v', 0 ); // extra field length
$cdrec .= pack('v', 0 ); // file comment length
$cdrec .= pack('v', 0 ); // disk number start
$cdrec .= pack('v', 0 ); // internal file attributes
$cdrec .= pack('V', 32 ); // external file attributes - 'archive' bit set
$cdrec .= pack('V', $this -> old_offset ); // relative offset of local header
$this -> old_offset = $new_offset;
$cdrec .= $name;
// optional extra field, file comment goes here
// save to central directory
$this -> ctrl_dir[] = $cdrec;
}
function filezip(){
$data = implode('', $this -> datasec);
$ctrldir = implode('', $this -> ctrl_dir);
return
$data .
$ctrldir .
$this -> eof_ctrl_dir .
pack('v', sizeof($this -> ctrl_dir)) . // total # of entries "on this disk"
pack('v', sizeof($this -> ctrl_dir)) . // total # of entries overall
pack('V', strlen($ctrldir)) . // size of central dir
pack('V', strlen($data)) . // offset to start of central dir
"\x00\x00"; // .zip file comment length
}
}
?>