class.tar.php

讲的是网络编程

				$header .= str_pad(decoct($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)
	{
		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"]	= $checksum;

		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");
		}
		$file_contents = fread($fp,filesize($filename));
		fclose($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;
	}
}

?>