Zip file creation class makes zip files on the fly...
use the functions add_dir() and add_file() to build the zip file; see example code below
by Eric Mueller http://www.themepark.com
v1.1 9-20-01 - added comments to example
v1.0 2-5-01
initial version with: - class appearance - add_file() and file() methods - gzcompress() output hacking by Denis O.Philippov, webmaster@atlant.ru, http://www.atlant.ru
*/
// official ZIP file format: http://www.pkware.com/appnote.txt
class zipfile {
var $datasec = array(); // array to store compressed data var $ctrl_dir = array(); // central directory var $eof_ctrl_dir = "\x50\x4b\x05\x06\x00\x00\x00\x00"; //end of Central directory record var $old_offset = 0;
function add_dir($name)
// adds "directory" to archive - do this before putting any files in directory! // $name - name of directory... like this: "path/" // ...then you can add files using add_file with names like "path/file.txt" { $name = str_replace("\\", "/", $name);
$fr = "\x50\x4b\x03\x04"; $fr .= "\x0a\x00"; // ver needed to extract $fr .= "\x00\x00"; // gen purpose bit flag $fr .= "\x00\x00"; // compression method $fr .= "\x00\x00\x00\x00"; // last mod time and date
// "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;
$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 .= "\x00\x00\x00\x00"; // last mod time and date
// "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;
// 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 .="\x00\x00\x00\x00"; // 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", $this -> old_offset ); //relative offset of local header // echo "old offset is ".$this->old_offset.", new offset is $new_offset<br>"; $this -> old_offset = $new_offset;
$cdrec .= $name; // optional extra field, file comment goes here // save to central directory $this -> ctrl_dir[] = $cdrec; }
function file() { // dump out file $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 } }
?>
/* example */
<?php
$zipfile = new zipfile();
// add the subdirectory ... important! $zipfile -> add_dir("dir/");
// add the binary data stored in the string 'filedata' $filedata = "(read your file into $filedata)"; $zipfile -> add_file($filedata, "dir/file.txt");
// the next three lines force an immediate download of the zip file: header("Content-type: application/octet-stream"); header("Content-disposition: attachment; filename=test.zip"); echo $zipfile -> file();
// OR instead of doing that, you can write out the file to the loca disk like this: $filename = "output.zip"; $fd = fopen ($filename, "wb"); $out = fwrite ($fd, $zipfile -> file()); fclose ($fd);
// then offer it to the user to download: <a href="output.zip">Click here to download the new zip file.</a>
?>
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