/src/lib/compressor.php

<?php

/**
 * Compression handler
 * ---
 * Written by Jose Carlos Nieto <xiam@menteslibres.org>
 * Copyright (c) 2007 Jose Carlos Nieto <xiam@menteslibres.org>
 *
 * Licensed under The MIT License
 * Redistributions of files must retain the above copyright notice.
 *
 * @author          Jose Carlos Nieto <xiam@menteslibres.org>
 * @copyright       Copyright (c) 2007-2008, Jose Carlos Nieto <xiam@menteslibres.org>
 * @link            http://opensource.astrata.com.mx Astrata Open Source Projects
 * @version         $Revision: 1115 $
 * @modifiedby      $LastChangedBy: xiam.core $
 * @lastmodified    $Date: 2008-05-26 14:32:25 +1000 (Mon, 26 May 2008) $
 * @license         http://www.opensource.org/licenses/mit-license.php The MIT License
 *
 */

class compressor extends tm_object {

  public function untar($file, $dest, $overwrite = true) {
    $env =& $this->using('env');

    /*
      *********************************************************
        This code portion is based on:
                        Simple Machines Forum
      *********************************************************
        URL: http://www.simplemachines.org
        License: GNU/GPL
        Copyright: (c) Lewis Media (http://www.lewismedia.com)
        Software Version: SMF 1.0.3
      **********************************************************
    */

    // fixing destination
    if (substr($dest, -1) != '/')
      $dest = $dest.'/';

    @mkdir($dest, 0777);

    // checking destination
    if (!is_writable($dest)) {
      $this->error('Could not untar, destination directory "'.$dest.'" is not writable.');
    }

    $fp = fopen($file, "r");

    $octdec = array('mode', 'uid', 'gid', 'size', 'mtime', 'checksum', 'type');
    $blocks = filesize($file)/512 - 1;

    $offset = 0;

    while ($offset < $blocks) {

      fseek($fp, $offset << 9);

      $header = fread($fp, 512);

      if (!($current = @unpack("a100filename/a8mode/a8uid/a8gid/a12size/a12mtime/a8checksum/a1type/a100linkname/a6magic/a2version/a32uname/a32gname/a8devmajor/a8devminor/a155path", $header))) {
        return false;
      }

      foreach ($current as $name => $value) {
        $current[$name]= trim($current[$name]);
        if (in_array($name, $octdec)) {
          $current[$name] = octdec($current[$name]);
        }
      }

      $checksum = 256;
      for ($i = 0; $i < 148; $i++) {
        $checksum += ord($header{$i});
      }
      for ($i = 156; $i < 512; $i++) {
        $checksum += ord($header{$i});
      }

      if ($current["checksum"] != $checksum) {
        if ($current["filename"]) {
          $env->error('Checksum error');
         } else {
           // Finished!
          return true;
        }
      }

      // protecting from parent directory writing
      $current["filename"] = preg_replace("/(\.\.\/|\/\.\.)/", "", $current["filename"]);

      $output = $dest.$current["filename"];

      $offset++;

      switch ($current["type"]) {
        case 5:
          // directory
          mkdir($output, 0755);
        break;
        default:
          if (!file_exists($output) || $overwrite) {
            fseek($fp, $offset << 9);

            $fh = fopen($output, 'wb');

            if ($current["size"]) {
              fwrite($fh, fread($fp, $current["size"]));
            }

            fclose($fh);
          }
        break;
      }
      $offset += ceil($current["size"]/512);
      @chmod($output, $current["mode"]);
    }
    fclose($fp);
    return true;
  }

  function unpack($file, $dest) {

    extract(
      $this->using(
        'archive',
        'env'
      )
    );

    @mkdir($dest, 0777);
  
    // Directory fix
    if (substr($dest, -1) != "/")
      $dest .= '/';
    
    if (!is_writable($dest)) {
      $this->error('Could not uncompress, destination directory "'.$dest.'" is not writable.');
    }

    if (($fp = fopen($file, "r")) != false) {

      $header = fread($fp, 4);

      fclose($fp);

      // guessing file type
      switch ($header) {
        case "\x1f\x8b\x08\x00":
          // gzip
          $fopen = "gzopen";
          $feof = "gzeof";
          $fread = "gzread";
          $fclose = "gzclose";
        break;
        case "\x42\x5a\x68\x39":
          // bzip2
          $fopen = "bzopen";
          $feof = "feof";
          $fread = "bzread";
          $fclose = "bzclose";

        break;
        case "\x50\x4b\x03\x04":
          // zip
          $zh = zip_open($file);

          while ($zfp = zip_read($zh)) {
            if (zip_entry_open($zh, $zfp, "w")) {
              $zipname = trim(zip_entry_name($zfp));
              // preventing hacks
              if (!preg_match("/\.\./", $zipname)) {
                $path = "{$dest}{$zipname}";
                if (substr($zipname, -1) == '/') {
                  mkdir($path, 0777);
                } else {
                  $fh = fopen ($path, "w");
                  fwrite($fh, zip_entry_read($zfp, zip_entry_filesize($zfp)));
                  fclose($fh);
                  zip_entry_close($zfp);
                }
                chmod ($path, 0775);
              }
            }
          }
          zip_close($zh);

          return true;
        break;
        default:

          if ($archive->extension($file) == "tar") {
            // let's suppose this is as a .tar archive
            $fopen = "fopen";
            $feof = "feof";
            $fread = "fread";
            $fclose = "fclose";
          } else {
            trigger_error("Unknown file type. You may specify .tar.gz, .tar.bz2, .zip or even .tar files only.", E_USER_ERROR);
          }
        break;
      }

      // temporary file name
      $temp = tempnam($dest, "tar");

      if (isset($fopen)) {
        // creating temporary file
        $tempf = fopen($temp, "w");

        // uncompressing
        $fi = $fopen($file, "r");
        while (!$feof($fi))
          fwrite($tempf, $fread($fi, 1024*1024));
        $fclose($fi);

        // closing temp file
        fclose($tempf);
      }

      $this->untar($temp, $dest);

      // removing temporary file
      unlink($temp);

      return true;
    } else {
      return false;
    }
  }

  static function run_test() {
    $c = new compressor();
    $c->unpack('/tmp/tm.tar.bz2', '/tmp/test_1');
    $c->unpack('/tmp/tm.tar.gz', '/tmp/test_2');
  }
}

// compressor::run_test();
?>