php生成zip压缩文件的方法详解

require_once "./include/zip.php";
$zip = new phpzip();
//$zip -> createzip("要压缩的文件夹目录地址", "压缩后的文件名.zip");　　 //只生成不自动下载
$zip -> downloadzip("要压缩的文件夹目录地址", "压缩后的文件名.zip");　　//自动下载

实例：可以参考下面的伪代码来看一个具体的使用场景：
代码

require_once "./include/zip.php";
if (!$download) {
exit();
}
set_time_limit(60);
$tmpmanager = new tmpmanager(); //假设我们有一个类来完成后面的操作
$tempfolder = array();
$tempfile = array();
//假设我们是通过在页面上选择checkbox来下载已选的文件夹或文件，并一同打包
for($i = 0;$i < $checkboxnum;$i++) {
$value = ${"select".$i};
if ($value != '') {
$this_type = substr($value, 0, 1);
$this_id = substr($value, 1);
//将文件夹和文件的情况分开处理
if ($this_type == 'd') {
$tempfolder[] = $this_id;
}
elseif ($this_type == 'f') {
$tempfile[] = $this_id;
}
}
}
@mkdir($tempdir);
$curtempdir = "$tempdir/".$userid; //不同用户在不同的临时文件夹下操作
if (file_exists($curtempdir)) {
$tmpmanager->deletedir($curtempdir); //删除旧的文件夹
}
if (sizeof($tempfolder) > 0 || sizeof($tempfile) > 0) {
mkdir($curtempdir, 0777); //如果有要打包的文件货文件夹，重新创建文件夹
}
if (sizeof($tempfile) > 0) {
$tmpmanager->copyfile($tempfile,$curtempdir); //将要下载的文件copy到创建的文件夹
}
if (sizeof($tempfolder) > 0) {
$tmpmanager->copyfolder($tempfolder,$curtempdir); //将要下载的文件夹copy到创建的文件夹
}
$zip = new phpzip();
$zip -> downloadzip($curtempdir, "file_".date('ymd').".zip"); //打包并下载

zip.php

<?php
/*
file name: /include/zip.php
author: horace 2009/04/15
*/
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
}
}
?>