zip.class.php

<?php
class zipfile
{
    /*
        zipfile class, for reading or writing .zip files
        See http://www.gamingg.net for more of my work
        Based on tutorial given by John Coggeshall at http://www.zend.com/zend/spotlight/creating-zip-files3.php
        Copyright (C) Joshua Townsend and licensed under the GPL
        Version 1.0
    */
    var $datasec = array(); // array to store compressed data
    var $files = array(); // array of uncompressed files
    var $dirs = array(); // array of directories that have been created already
    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;
    var $basedir = ".";

    function create_dir($name) // Adds a directory to the zip with the name $name
    {
        $name = str_replace("\\", "/", $name);

        $fr = "\x50\x4b\x03\x04";
        $fr .= "\x0a\x00";  // version needed to extract
        $fr .= "\x00\x00";  // general purpose bit flag
        $fr .= "\x00\x00";  // compression method
        $fr .= "\x00\x00\x00\x00"; // last mod time and date

        $fr .= pack("V",0); // crc32
        $fr .= pack("V",0); //compressed filesize
        $fr .= pack("V",0); //uncompressed filesize
        $fr .= pack("v",strlen($name)); //length of pathname
        $fr .= pack("v", 0); //extra field length
        $fr .= $name;
        // end of "local file header" segment

        // no "file data" segment for path

        // "data descriptor" segment (optional but necessary if archive is not served as file)
        $fr .= pack("V",0); //crc32
        $fr .= pack("V",0); //compressed filesize
        $fr .= pack("V",0); //uncompressed filesize

        // add this entry to array
        $this->datasec[] = $fr;

        $new_offset = strlen(implode("", $this->datasec));

        // ext. file attributes mirrors MS-DOS directory attr byte, detailed
        // at http://support.microsoft.com/support/kb/articles/Q125/0/19.asp

        // now add to central record
        $cdrec = "\x50\x4b\x01\x02";
        $cdrec .="\x00\x00";    // version made by
        $cdrec .="\x0a\x00";    // version needed to extract
        $cdrec .="\x00\x00";    // general purpose bit flag
        $cdrec .="\x00\x00";    // compression method
        $cdrec .="\x00\x00\x00\x00"; // last mod time and date
        $cdrec .= pack("V",0); // crc32
        $cdrec .= pack("V",0); //compressed filesize
        $cdrec .= pack("V",0); //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", 16 ); //external file attributes  - 'directory' 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 array
        $this->ctrl_dir[] = $cdrec;
        $this->dirs[] = $name;
    }


    function create_file($data, $name) // Adds a file to the path specified by $name with the contents $data
    {
        $name = str_replace("\\", "/", $name);

        $fr = "\x50\x4b\x03\x04";
        $fr .= "\x14\x00";  // version needed to extract
        $fr .= "\x00\x00";  // general purpose bit flag
        $fr .= "\x08\x00";  // compression method
        $fr .= "\x00\x00\x00\x00"; // last mod time and date

        $unc_len = strlen($data);
        $crc = crc32($data);
        $zdata = gzcompress($data);
        $zdata = substr($zdata, 2, -4); // fix crc bug
        $c_len = strlen($zdata);
        $fr .= pack("V",$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;
        // end of "local file header" segment

        // "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";    // general 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
        $this->old_offset = $new_offset;

        $cdrec .= $name;
        // optional extra field, file comment goes here
        // save to central directory
        $this->ctrl_dir[] = $cdrec;
    }

    function read_zip($name)
    {
        // Clear current file
        $this->datasec = array();

        // File information
        $this->name = $name;
        $this->mtime = filemtime($name);
        $this->size = filesize($name);

        // Read file
        $fh = fopen($name, "rb");
        $filedata = fread($fh, $this->size);
        fclose($fh);

        // Break into sections
        $filesecta = explode("\x50\x4b\x05\x06", $filedata);

        // ZIP Comment
        $unpackeda = unpack('x16/v1length', $filesecta[1]);
        $this->comment = substr($filesecta[1], 18, $unpackeda['length']);
        $this->comment = str_replace(array("\r\n", "\r"), "\n", $this->comment); // CR + LF and CR -> LF

        // Cut entries from the central directory
        $filesecta = explode("\x50\x4b\x01\x02", $filedata);
        $filesecta = explode("\x50\x4b\x03\x04", $filesecta[0]);
        array_shift($filesecta); // Removes empty entry/signature

        foreach($filesecta as $filedata)
        {
            // CRC:crc, FD:file date, FT: file time, CM: compression method, GPF: general purpose flag, VN: version needed, CS: compressed size, UCS: uncompressed size, FNL: filename length
            $entrya = array();
            $entrya['error'] = "";

            $unpackeda = unpack("v1version/v1general_purpose/v1compress_method/v1file_time/v1file_date/V1crc/V1size_compressed/V1size_uncompressed/v1filename_length", $filedata);

            // Check for encryption
            $isencrypted = (($unpackeda['general_purpose'] & 0x0001) ? true : false);

            // Check for value block after compressed data
            if($unpackeda['general_purpose'] & 0x0008)
            {
                $unpackeda2 = unpack("V1crc/V1size_compressed/V1size_uncompressed", substr($filedata, -12));

                $unpackeda['crc'] = $unpackeda2['crc'];
                $unpackeda['size_compressed'] = $unpackeda2['size_uncompressed'];
                $unpackeda['size_uncompressed'] = $unpackeda2['size_uncompressed'];

                unset($unpackeda2);
            }

            $entrya['name'] = substr($filedata, 26, $unpackeda['filename_length']);

            if(substr($entrya['name'], -1) == "/") // skip directories
            {
                continue;
            }

            $entrya['dir'] = dirname($entrya['name']);
            $entrya['dir'] = ($entrya['dir'] == "." ? "" : $entrya['dir']);
            $entrya['name'] = basename($entrya['name']);


            $filedata = substr($filedata, 26 + $unpackeda['filename_length']);

            if(strlen($filedata) != $unpackeda['size_compressed'])
            {
                $entrya['error'] = "Compressed size is not equal to the value given in header.";
            }

            if($isencrypted)
            {
                $entrya['error'] = "Encryption is not supported.";
            }
            else
            {
                switch($unpackeda['compress_method'])
                {
                    case 0: // Stored
                        // Not compressed, continue
                    break;
                    case 8: // Deflated
                        $filedata = gzinflate($filedata);
                    break;
                    case 12: // BZIP2
                        if(!extension_loaded("bz2"))
                        {
                            @dl((strtolower(substr(PHP_OS, 0, 3)) == "win") ? "php_bz2.dll" : "bz2.so");
                        }

                        if(extension_loaded("bz2"))
                        {
                            $filedata = bzdecompress($filedata);
                        }
                        else
                        {
                            $entrya['error'] = "Required BZIP2 Extension not available.";
                        }
                    break;
                    default:
                        $entrya['error'] = "Compression method ({$unpackeda['compress_method']}) not supported.";
                }

                if(!$entrya['error'])
                {
                    if($filedata === false)
                    {
                        $entrya['error'] = "Decompression failed.";
                    }
                    elseif(strlen($filedata) != $unpackeda['size_uncompressed'])
                    {
                        $entrya['error'] = "File size is not equal to the value given in header.";
                    }
                    elseif(crc32($filedata) != $unpackeda['crc'])
                    {
                        $entrya['error'] = "CRC32 checksum is not equal to the value given in header.";
                    }
                }

                $entrya['filemtime'] = mktime(($unpackeda['file_time']  & 0xf800) >> 11,($unpackeda['file_time']  & 0x07e0) >>  5, ($unpackeda['file_time']  & 0x001f) <<  1, ($unpackeda['file_date']  & 0x01e0) >>  5, ($unpackeda['file_date']  & 0x001f), (($unpackeda['file_date'] & 0xfe00) >>  9) + 1980);
                $entrya['data'] = $filedata;
            }

            $this->files[] = $entrya;
        }

        return $this->files;
    }

    function add_file($file, $dir = ".", $file_blacklist = array(), $ext_blacklist = array())
    {
        $file = str_replace("\\", "/", $file);
        $dir = str_replace("\\", "/", $dir);

        if(strpos($file, "/") !== false)
        {
            $dira = explode("/", "{$dir}/{$file}");
            $file = array_shift($dira);
            $dir = implode("/", $dira);
            unset($dira);
        }

        while(substr($dir, 0, 2) == "./")
        {
            $dir = substr($dir, 2);
        }
        while(substr($file, 0, 2) == "./")
        {
            $file = substr($file, 2);
        }
        if(!in_array($dir, $this->dirs))
        {
            if($dir == ".")
            {
                $this->create_dir("./");
            }
            $this->dirs[] = $dir;
        }
        if(in_array($file, $file_blacklist))
        {
            return true;
        }
        foreach($ext_blacklist as $ext)
        {
            if(substr($file, -1 - strlen($ext)) == ".{$ext}")
            {
                return true;
            }
        }

        $filepath = (($dir && $dir != ".") ? "{$dir}/" : "").$file;
        if(is_dir("{$this->basedir}/{$filepath}"))
        {
            $dh = opendir("{$this->basedir}/{$filepath}");
            while(($subfile = readdir($dh)) !== false)
            {
                if($subfile != "." && $subfile != "..")
                {
                    $this->add_file($subfile, $filepath, $file_blacklist, $ext_blacklist);
                }
            }
            closedir($dh);
        }
        else
        {
            $this->create_file(implode("", file("{$this->basedir}/{$filepath}")), $filepath);
        }

        return true;
    }


    function zipped_file() // return zipped file contents
    {
        $data = implode("", $this->datasec);
        $ctrldir = implode("", $this->ctrl_dir);

        return $data.
                $ctrldir.
                $this->eof_ctrl_dir.
                pack("v", sizeof($this->ctrl_dir)). // total number of entries "on this disk"
                pack("v", sizeof($this->ctrl_dir)). // total number of entries overall
                pack("V", strlen($ctrldir)). // size of central dir
                pack("V", strlen($data)). // offset to start of central dir
                "\x00\x00"; // .zip file comment length
    }
}
?>