HomePHP Page 2 - TAR File Management With PHP Archive_Tar
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Need to create or manipulate a TAR file through your Web browser? Take a look at the PEAR Archive_Tar class, which exposes a simple, yet extremely powerful, API to perform manipulation of TAR and TGZ archives through a PHP script. Possible applications include a TAR file viewer and a Web-based backup utility.
The Archive_Tar class is brought to you by PEAR, the PHP Extension and Application Repository (http://pear.php.net). In case you didn't know, PEAR is an online repository of free PHP software, including classes and modules for everything from data archiving to XML parsing. When you install PHP, a whole bunch of PEAR modules get installed as well; the Archive_Tar class is one of them.
In case your PHP distribution didn't include Archive_Tar, or if you chose not to install the PEAR component, you can get yourself a copy from the official PEAR Web site, at http://pear.php.net - simply unzip the distribution archive into your PEAR directory and you're ready to roll!
Let's begin with something simple - packing a bunch of files into a single TAR archive with Archive_Tar object methods (this tutorial uses Archive_Tar 1.11).
<?php
// include class
require("Tar.php");
// create Archive_Tar() object
// specify filename for output file
$tar = new Archive_Tar("data.tar");
// set up file list
$files = array("package.dtd", "package.xml", "filter.xsl",
"../../includes/php/adodb.php");
// build archive
$tar->create($files) or die("Could not create archive!");
?>
This is a pretty simple script, but I'll hit the high points anyway:
1. The first step, as always, is to include the required class file in your script.
<?php
// include class
require("Tar.php");
?>
You can either provide an absolute path to this file, or do what most lazy programmers do - include the path to your PEAR installation in PHP's "include_path" variable, so that you can access any of the PEAR classes without needing to type in long, convoluted file paths.
2. The next step is to instantiate an object of the Archive_Tar class.
<?php
// create Archive_Tar() object
// specify filename for output file
$tar = new Archive_Tar("data.tar");
?>
Note that the object constructor requires, as argument, the name of the TAR file to be created. You can include a path here as well if you would like the file to be created in a location other than the current directory.
3. Third, you need to tell the newly-created object which files to include in the archive. This information is provided to the object's create() method as an array of file names.
<?php
// set up file list
$files = array("package.dtd", "package.xml", "filter.xsl",
"../../includes/php/adodb.php");
// build archive
$tar->create($files) or die("Could not create archive!");
?>
Obviously, you should replace the file list in the example above with information that reflects your own system. If Archive_Tar cannot locate any of the files specified in the file list, it will simply skip over it to the next one.
Note that the create() method will replace a previously-existing file with the same name. If you don't want this to happen, you should wrap your call to create() in a file_exists() test.
Once you run this script through your browser, you'll see that a file named "data.tar" appears in the same directory as the script.
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