Ubilling/modules/system/tar.php

<?php

class tar {

    var $filename;
    var $isGzipped;
    var $tar_file;
    var $files;
    var $directories;
    var $numFiles;
    var $numDirectories;

    public function __construct() {
        return true;
    }

    /**
     * Computes the unsigned Checksum of a file's header
     * to try to ensure valid file
     * 
     * @param	string  $bytestring
     * 
     * @access	private
     */
    function __computeUnsignedChecksum($bytestring) {
        $unsigned_chksum = '';
        for ($i = 0; $i < 512; $i++)
            @$unsigned_chksum += ord($bytestring[$i]);
        for ($i = 0; $i < 8; $i++)
            @$unsigned_chksum -= ord($bytestring[148 + $i]);
        @$unsigned_chksum += ord(" ") * 8;

        return $unsigned_chksum;
    }

    /**
     * Converts a NULL padded string to a non-NULL padded string
     * 
     * @param   string  $string
     * 
     * @return  string 
     * 
     * @access	private
     * */
    function __parseNullPaddedString($string) {
        $position = strpos($string, chr(0));
        return substr($string, 0, $position);
    }

    /**
     * This function parses the current TAR file
     * 
     * @return  bool    always TRUE
     * 
     * @access	private
     * */
    function __parseTar() {
        // Read Files from archive
        $tar_length = strlen($this->tar_file);
        $main_offset = 0;
        $this->numFiles = 0;
        while ($main_offset < $tar_length) {
            // If we read a block of 512 nulls, we are at the end of the archive
            if (substr($this->tar_file, $main_offset, 512) == str_repeat(chr(0), 512))
                break;

            // Parse file name
            $file_name = $this->__parseNullPaddedString(substr($this->tar_file, $main_offset, 100));

            // Parse the file mode
            $file_mode = substr($this->tar_file, $main_offset + 100, 8);

            // Parse the file user ID
            $file_uid = octdec(substr($this->tar_file, $main_offset + 108, 8));

            // Parse the file group ID
            $file_gid = octdec(substr($this->tar_file, $main_offset + 116, 8));

            // Parse the file size
            $file_size = octdec(substr($this->tar_file, $main_offset + 124, 12));

            // Parse the file update time - unix timestamp format
            $file_time = octdec(substr($this->tar_file, $main_offset + 136, 12));

            // Parse Checksum
            $file_chksum = octdec(substr($this->tar_file, $main_offset + 148, 6));

            // Parse user name
            $file_uname = $this->__parseNullPaddedString(substr($this->tar_file, $main_offset + 265, 32));

            // Parse Group name
            $file_gname = $this->__parseNullPaddedString(substr($this->tar_file, $main_offset + 297, 32));

            // Make sure our file is valid
            if ($this->__computeUnsignedChecksum(substr($this->tar_file, $main_offset, 512)) != $file_chksum)
                return false;

            // Parse File Contents
            $file_contents = substr($this->tar_file, $main_offset + 512, $file_size);

            /* 	### Unused Header Information ###
              $activeFile["typeflag"]		= substr($this->tar_file,$main_offset + 156,1);
              $activeFile["linkname"]		= substr($this->tar_file,$main_offset + 157,100);
              $activeFile["magic"]		= substr($this->tar_file,$main_offset + 257,6);
              $activeFile["version"]		= substr($this->tar_file,$main_offset + 263,2);
              $activeFile["devmajor"]		= substr($this->tar_file,$main_offset + 329,8);
              $activeFile["devminor"]		= substr($this->tar_file,$main_offset + 337,8);
              $activeFile["prefix"]		= substr($this->tar_file,$main_offset + 345,155);
              $activeFile["endheader"]	= substr($this->tar_file,$main_offset + 500,12);
             */

            if ($file_size > 0) {
                // Increment number of files
                $this->numFiles++;

                // Create us a new file in our array
                $activeFile = &$this->files[];

                // Asign Values
                $activeFile["name"] = $file_name;
                $activeFile["mode"] = $file_mode;
                $activeFile["size"] = $file_size;
                $activeFile["time"] = $file_time;
                $activeFile["user_id"] = $file_uid;
                $activeFile["group_id"] = $file_gid;
                $activeFile["user_name"] = $file_uname;
                $activeFile["group_name"] = $file_gname;
                $activeFile["checksum"] = $file_chksum;
                $activeFile["file"] = $file_contents;
            } else {
                // Increment number of directories
                $this->numDirectories++;

                // Create a new directory in our array
                $activeDir = &$this->directories[];

                // Assign values
                $activeDir["name"] = $file_name;
                $activeDir["mode"] = $file_mode;
                $activeDir["time"] = $file_time;
                $activeDir["user_id"] = $file_uid;
                $activeDir["group_id"] = $file_gid;
                $activeDir["user_name"] = $file_uname;
                $activeDir["group_name"] = $file_gname;
                $activeDir["checksum"] = $file_chksum;
            }

            // Move our offset the number of blocks we have processed
            $main_offset += 512 + (ceil($file_size / 512) * 512);
        }

        return true;
    }

    /**
     * Read a non gzipped tar file in for processing.
     * 
     * @param   string  $filename   full filename
     * @return  bool    always TRUE
     * 
     * @access	private
     * */
    function __readTar($filename = '') {
        // Set the filename to load
        if (!$filename)
            $filename = $this->filename;

        // Read in the TAR file
        $fp = fopen($filename, "rb");
        $this->tar_file = fread($fp, filesize($filename));
        fclose($fp);

        if ($this->tar_file[0] == chr(31) && $this->tar_file[1] == chr(139) && $this->tar_file[2] == chr(8)) {
            if (!function_exists("gzinflate"))
                return false;

            $this->isGzipped = true;

            $this->tar_file = gzinflate(substr($this->tar_file, 10, -4));
        }

        // Parse the TAR file
        $this->__parseTar();

        return true;
    }

    /**
     * Generates a TAR file from the processed data
     * 
     * @return  bool    always TRUE
     * 
     * @access	private
     * */
    function __generateTAR() {
        $this->tar_file = '';

        // Generate Records for each directory, if we have directories
        if ($this->numDirectories > 0) {
            foreach ($this->directories as $key => $information) {
                unset($header);

                // Generate tar header for this directory
                // Filename, Permissions, UID, GID, size, Time, checksum, typeflag, linkname, magic, version, user name, group name, devmajor, devminor, prefix, end
                $header = str_pad($information["name"], 100, chr(0));
                $header .= str_pad(decoct($information["mode"]), 7, "0", STR_PAD_LEFT) . chr(0);
                $header .= str_pad(decoct($information["user_id"]), 7, "0", STR_PAD_LEFT) . chr(0);
                $header .= str_pad(decoct($information["group_id"]), 7, "0", STR_PAD_LEFT) . chr(0);
                $header .= str_pad(decoct(0), 11, "0", STR_PAD_LEFT) . chr(0);
                $header .= str_pad(decoct($information["time"]), 11, "0", STR_PAD_LEFT) . chr(0);
                $header .= str_repeat(" ", 8);
                $header .= "5";
                $header .= str_repeat(chr(0), 100);
                $header .= str_pad("ustar", 6, chr(32));
                $header .= chr(32) . chr(0);
                $header .= str_pad("", 32, chr(0));
                $header .= str_pad("", 32, chr(0));
                $header .= str_repeat(chr(0), 8);
                $header .= str_repeat(chr(0), 8);
                $header .= str_repeat(chr(0), 155);
                $header .= str_repeat(chr(0), 12);

                // Compute header checksum
                $checksum = str_pad(decoct($this->__computeUnsignedChecksum($header)), 6, "0", STR_PAD_LEFT);
                for ($i = 0; $i < 6; $i++) {
                    $header[(148 + $i)] = substr($checksum, $i, 1);
                }
                $header[154] = chr(0);
                $header[155] = chr(32);

                // Add new tar formatted data to tar file contents
                $this->tar_file .= $header;
            }
        }

        // Generate Records for each file, if we have files (We should...)
        if ($this->numFiles > 0) {
            foreach ($this->files as $key => $information) {
                // Generate the TAR header for this file
                // Filename, Permissions, UID, GID, size, Time, checksum, typeflag, linkname, magic, version, user name, group name, devmajor, devminor, prefix, end
                $header = str_pad($information['name'], 100, chr(0));
                $header .= str_pad(decoct($information['mode']), 7, "0", STR_PAD_LEFT) . chr(0);
                $header .= str_pad(decoct($information['user_id']), 7, "0", STR_PAD_LEFT) . chr(0);
                $header .= str_pad(decoct($information['group_id']), 7, "0", STR_PAD_LEFT) . chr(0);
                $header .= str_pad(decoct($information['size']), 11, "0", STR_PAD_LEFT) . chr(0);
                $header .= str_pad(decoct($information['time']), 11, "0", STR_PAD_LEFT) . chr(0);
                $header .= str_repeat(" ", 8);
                $header .= "0";
                $header .= str_repeat(chr(0), 100);
                $header .= str_pad("ustar", 6, chr(32));
                $header .= chr(32) . chr(0);
                $header .= str_pad($information["user_name"], 32, chr(0)); // How do I get a file's user name from PHP?
                $header .= str_pad($information["group_name"], 32, chr(0)); // How do I get a file's group name from PHP?
                $header .= str_repeat(chr(0), 8);
                $header .= str_repeat(chr(0), 8);
                $header .= str_repeat(chr(0), 155);
                $header .= str_repeat(chr(0), 12);

                // Compute header checksum
                $checksum = str_pad(decoct($this->__computeUnsignedChecksum($header)), 6, "0", STR_PAD_LEFT);
                for ($i = 0; $i < 6; $i++) {
                    $header[(148 + $i)] = substr($checksum, $i, 1);
                }
                $header[154] = chr(0);
                $header[155] = chr(32);

                // Pad file contents to byte count divisible by 512
                $file_contents = str_pad($information["file"], (ceil($information["size"] / 512) * 512), chr(0));

                // Add new tar formatted data to tar file contents
                $this->tar_file .= $header . $file_contents;
            }
        }

        // Add 512 bytes of NULLs to designate EOF
        $this->tar_file .= str_repeat(chr(0), 512);

        return true;
    }

    /**
     * Open a TAR file
     * 
     * @param   string  $filename
     * @return  bool 
     * */
    function openTAR($filename) {
        // Clear any values from previous tar archives
        unset($this->filename);
        unset($this->isGzipped);
        unset($this->tar_file);
        unset($this->files);
        unset($this->directories);
        unset($this->numFiles);
        unset($this->numDirectories);

        // If the tar file doesn't exist...
        if (!file_exists($filename))
            return false;

        $this->filename = $filename;

        // Parse this file
        $this->__readTar();

        return true;
    }

    /**
     * Appends a tar file to the end of the currently opened tar file.
     * 
     * @param   string  $filename
     * @return  bool
     * */
    function appendTar($filename) {
        // If the tar file doesn't exist...
        if (!file_exists($filename))
            return false;

        $this->__readTar($filename);

        return true;
    }

    /**
     * Retrieves information about a file in the current tar archive
     * 
     * @param   string  $filename
     * @return  string  FALSE on fail
     * */
    function getFile($filename) {
        if ($this->numFiles > 0) {
            foreach ($this->files as $key => $information) {
                if ($information["name"] == $filename)
                    return $information;
            }
        }

        return false;
    }

    /**
     * Retrieves information about a directory in the current tar archive
     * 
     * @param   string  $dirname
     * @return  string  FALSE on fail
     * */
    function getDirectory($dirname) {
        if ($this->numDirectories > 0) {
            foreach ($this->directories as $key => $information) {
                if ($information["name"] == $dirname)
                    return $information;
            }
        }

        return false;
    }

    /**
     * Check if this tar archive contains a specific file
     * 
     * @param   string  $filename
     * @return  bool
     * */
    function containsFile($filename) {
        if ($this->numFiles > 0) {
            foreach ($this->files as $key => $information) {
                if ($information["name"] == $filename)
                    return true;
            }
        }
        return false;
    }

    /**
     * Check if this tar archive contains a specific directory
     * 
     * @param   string  $dirname
     * @return  bool
     * */
    function containsDirectory($dirname) {
        if ($this->numDirectories > 0) {
            foreach ($this->directories as $key => $information) {
                if ($information["name"] == $dirname) {
                    return true;
                }
            }
        }
        return false;
    }

    /**
     * Add a directory to this tar archive
     * 
     * @param   string  $dirname
     * @return  bool
     * */
    function addDirectory($dirname, $recurse = false) {
        if (!file_exists($dirname)) {
            return false;
        }

        // Get directory information
        $file_information = stat($dirname);

        // Add directory to processed data
        $this->numDirectories++;
        $activeDir = &$this->directories[];
        $activeDir["name"] = $dirname;
        $activeDir["mode"] = @$file_information["mode"];
        $activeDir["time"] = @$file_information["time"];
        $activeDir["user_id"] = @$file_information["uid"];
        $activeDir["group_id"] = @$file_information["gid"];
        $activeDir["checksum"] = 0;

        if ($recurse) {
            $cdir = opendir($dirname);
            while ($element = readdir($cdir)) {
                if ($element != '.' && $element != '..') {
                    if (is_dir($dirname . '/' . $element)) {
                        $this->addDirectory($dirname . '/' . $element, true);
                    } else {
                        $this->addFile($dirname . '/' . $element);
                    }
                }
            }
            closedir($cdir);
        }

        return true;
    }

    /**
     * Add a file to the tar archive
     * 
     * @param   string  $filename
     * @param   boolean $binary     Binary file?
     * @return  bool
     * */
    function addFile($filename, $binary = false) {
        // Make sure the file we are adding exists!
        if (!file_exists($filename)) {
            return false;
        }

        // Make sure there are no other files in the archive that have this same filename
        if ($this->containsFile($filename)) {
            return false;
        }

        // Get file information
        $file_information = stat($filename);

        // Read in the file's contents
        if (!$binary) {
            $fp = fopen($filename, "r");
        } else {
            $fp = fopen($filename, "rb");
        }
        if (filesize($filename) !== 0)
            $file_contents = fread($fp, filesize($filename));
        else
            $file_contents = '';
        fclose($fp);

        // Add file to processed data
        $this->numFiles++;
        $activeFile = &$this->files[];
        $activeFile["name"] = $filename;
        $activeFile["mode"] = $file_information["mode"];
        $activeFile["user_id"] = $file_information["uid"];
        $activeFile["group_id"] = $file_information["gid"];
        $activeFile["size"] = $file_information["size"];
        $activeFile["time"] = $file_information["mtime"];
        $activeFile["checksum"] = isset($checksum) ? $checksum : '';
        $activeFile["user_name"] = "";
        $activeFile["group_name"] = "";
        $activeFile["file"] = trim($file_contents);

        return true;
    }

    /**
     * Remove a file from the tar archive
     * 
     * @param   string  $filename
     * @return  bool
     * */
    function removeFile($filename) {
        if ($this->numFiles > 0) {
            foreach ($this->files as $key => $information) {
                if ($information["name"] == $filename) {
                    $this->numFiles--;
                    unset($this->files[$key]);
                    return true;
                }
            }
        }
        return false;
    }

    /**
     * Remove a directory from the tar archive
     * 
     * @param   string  $dirname
     * @return  bool
     * */
    function removeDirectory($dirname) {
        if ($this->numDirectories > 0) {
            foreach ($this->directories as $key => $information) {
                if ($information["name"] == $dirname) {
                    $this->numDirectories--;
                    unset($this->directories[$key]);
                    return true;
                }
            }
        }
        return false;
    }

    /**
     * Write the currently loaded tar archive to disk
     * 
     * @return  bool 
     * */
    function saveTar() {
        if (!$this->filename) {
            return false;
        }

        // Write tar to current file using specified gzip compression
        $this->toTar($this->filename, $this->isGzipped);

        return true;
    }

    /**
     * Saves tar archive to a different file than the current file
     * 
     * @param   string  $filename
     * @param   bool    $useGzip    Use GZ compression?
     * @return  bool
     * */
    function toTar($filename, $useGzip) {
        if (!$filename) {
            return false;
        }
        // Encode processed files into TAR file format
        $this->__generateTar();

        // GZ Compress the data if we need to
        if ($useGzip) {
            // Make sure we have gzip support
            if (!function_exists("gzencode")) {
                return false;
            }

            $file = gzencode($this->tar_file);
        } else {
            $file = $this->tar_file;
        }

        // Write the TAR file
        $fp = fopen($filename, "wb");
        fwrite($fp, $file);
        fclose($fp);

        return true;
    }

    /**
     * Sends tar archive to stdout
     * 
     * @param   string  $filename
     * @param   bool    $useGzip    Use GZ compression?
     * @return  string
     * */
    function toTarOutput($filename, $useGzip) {
        if (!$filename) {
            return false;
        }

        // Encode processed files into TAR file format
        $this->__generateTar();

        // GZ Compress the data if we need to
        if ($useGzip) {
            // Make sure we have gzip support
            if (!function_exists("gzencode")) {
                return false;
            }

            $file = gzencode($this->tar_file);
        } else {
            $file = $this->tar_file;
        }

        return $file;
    }

}

?>