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John’s Top PECL Picks

John Coggeshall

Welcome to the session

• Welcome to the session!

• Who am I: John Coggeshall Lead, North American

Professional Services PHP 5 Core Contributor Author: PHP 5 Unleashed Member of Zend’s Education

Advisory Board

Apr 18, 2023 # 2

What is PECL?

• PECL: PHP Extension Community Library A collection of C level PHP extensions for PHP A spin off from PEAR

• PHP Extension and Application Repository

What is PECL?

• Historically, the PHP community looked to PECL as a way to manage the release process for extensions Allow each extension developer to maintain their

extension outside of the core PHP Marginally successful in that regard

• Practically, PECL is a collection of PHP extensions which do not have consensus in the core distribution Less oversight into code quality / completeness More like Perl’s CPAN

Using PECL extensions

• Using PECL extensions is fairly straightforward A few options are available

• Option 1: Use the pecl tool $ pecl install fileinfo Downloads the extension, configure and compiles it

for use on your architecture Not always available

• Option 2: Compile it yourself A more advanced approach Complicates acquiring / installing the extension Should work in almost every case

Compiling PECL from source

• When the PECL tool is unavailable, you can install PECL extensions by.. Downloading the extension’s latest release Extracting the tarball Running phpize

• Creates a configuration script just for this extension

Compiling the extension

• Creates a shared library Enabling using the extension php.ini directive

• i.e. extension=fileinfo.so

Compiling PECL from source

$ tar –zxvf mypeclext.tgz$ cd mypeclext/$ phpize$ ./configure $ make$ make install

• Compiling example:

What about Windows?

• You can use PECL in PHP installations running on Windows as well Actually, it’s much easier

• Just download the extension from the PHP web site (pre-compiled) pecl4win.php.net

• Once downloaded just copy to your extensions directory and enable from php.ini

Copyright © 2006, Zend Technologies Inc.

My Favorite PECL Extensions

About my picks

• My PECL Picks are based on a number of criteria, which may or may not agree with yours Direct experience using them Quality of code / Trusted Developers Interesting Emerging Technologies

• For the most part my selections have to do with data manipulation Everyone knows about compiler caches and

debuggers already

Fileinfo Extension

• Very often when uploading files you want to verify what is being uploaded Verifying extension isn’t enough Most browsers lie about mime type based on the file

extension

• Fileinfo to the rescue Detect MIME types for files based on their content Uses a “magic” database for determining the type

Fileinfo Extension

• Using Fileinfo is straightforward:

$info = new finfo(FILEINFO_MIME);echo “The Mime Type is: “ . $info->file(‘/tmp/myfile.mpg’);

• If your “magic” library isn’t in the standard directory you can pass the path as the second constructor parameter:

$info = new finfo(FILEINFO_MIME, “/path/to/file/magic”);

Phar Extension

• What’s Phar? PHP Archive Files Similar to Java .JAR files

• Effectively a virtual file system tailored to PHP

• Based on the PEAR PHP implementation and specification

• Can store any type of resource you might need for your PHP applications

Creating Phars

• Once you have the Phar extension installed, the first order of business is creating a new Phar file

• Two ways to create Phars Using streams:

file_put_contents(‘phar:///full/path/to/application.phar/file.php’, ‘<?php print “Hello World!”; ?>’);

Or by using a Phar object directly:

$phar = new Phar(‘/full/path/to/application.phar’, 0, ‘application.phar’);$phar[‘file.php’] = ‘<?php print “Hello World!”; ?>’;

Creating Phars

• When creating Phar files using the object approach a number of tools are available Compression on a per-resource basis

$phar[‘realbigfile.data’]->setCompressedGZ();

You can also assign meta-data to any resource in the archive, as well as the archive itself…

$phar[‘images/myimage.png’]->setMetaData(array(‘mime’ => ‘image/png’));

$phar->setMetadata(array(‘bootstrap’ => ‘index.php’));

Using Phar files

• Using Phar files is identical to using normal PHP scripts in many ways You can simply include a .phar file:

Include_once ‘library.phar’;

• You can also use stream-access to load specific resources from the Phar:

Include_once ‘phar://library.phar/myfiles/file.php’;

• Note: Phar archives cannot work against remote resources

Using Phar files

• When a Phar file is opened, you can use the object as an array to manipulate the archive:<?php

$phar = new Phar(‘/path/to/application.phar’, 0, ‘myapp.phar’);

// Get a PharFileInfo instance// uses phar://myapp.phar/file.php$phar_info = $phar[‘file.php’];

// Create a new file (or overwrite) called file.php with the contents $contents$phar[‘file.php’] = $contents;

// Check to see if a file exists within a pharIf(isset($phar[‘file.php’]))…

// Erase a file from the pharunset($phar[‘file.php’]);

Using Phar files

• Phars can be executed directly creating a bootstrap file..

$phar->setMetadata(array(‘bootstrap’ => ‘index.php’));

[/home/john]$ php application.phar

<?php /* index.php */

$p = new Phar(__FILE__); $m = $p->getMetaData(); require "phar://" . __FILE__ . "/" . $m["bootstrap"];__HALT_COMPILER(); ?>

XDiff

• XDiff is a very useful extension for working with different versions of a file Very similar to the UNIX diff command Can be used to determine the differences between

two versions of the same file Create Patches from one file to the next Can be combined with the likes of fileinfo/phar to

create robust package management and upgrading

Using XDiff

• Creating Diffs is easy

<?php

xdiff_file_diff(“input1.txt”, “input2.txt”, “output.txt”);

• Which produces an output.txt with…

@@ -1,1 +1,1 @@-Hello+Hello, World!

• Each parameter is a stream, and xdiff_string_diff() is also available

Patching using XDiff

• Just like normal UNIX diff, the output created can be used to apply changes to the original file

@@ -1,1 +1,1 @@-Hello+Hello, World!

<?php

$patch = file_get_contents(‘mypatch.diff’);$original = file_get_contents(‘myfile.txt’);

$patched = xdiff_string_patch($original, $patch);

file_put_contents(‘myfilepatched.txt’, $patched);

More XDiff Goodies

• It’s worthwhile to mention you can create diffs on binary data as easily as text xdiff_file_diff_binary() xdiff_file_patch_binary()

• Using the in-memory diffs you can store incremental changes on just about anything Store database schema changes, or store diffs in the

database Combine with Phar to create update / rollback

packages

Zip extension

• The PECL Zip extension is a replacement for the zip extension previously shipped with PHP Much improved from a functional and usability

standpoint Allows for the easy creation, and reading of Zip

archive files Object oriented interface (Very) Actively maintained

Using Zip: Creating Archives

• You can use Zip to create archives easily ZipArchive::addFile() to add files ZipArchive::addFromString() to add from PHP

variables

<?php $zip = new ZipArchive();

$zip->open(‘myarchive.zip’, ZIPARCHIVE::CREATE);

$zip->addFile(‘/path/to/myfile.dat’, ‘newname.dat’); $zip->addFromString(‘myfile.txt’, ‘This is my file…’); print “Total files: “ . $zip->numFiles; $zip->close();?>

Using Zip: Reading Archives

• You can read archives using the Zip extension in a few ways Using Streams Using the API

• Stream example:

$uncompressed = file_get_contents(‘zip://myarchive.zip#myfile.txt’);

Using Zip: Reading Archives

• You can also use the API of the ZipArchive class to extract files as well

<?php

$zip = new ZipArchive();

$zip->open(‘myarchive.zip’);$zip->extractTo(‘mydirectory’);$zip->close();

<?php

$zip = new ZipArchive();

$zip->open(‘myarchive.zip’);$zip->extractTo(‘.’, array(‘file1.txt’, ‘file2.txt’));$zip->close();

SSH2 Extension

• The SSH2 extension is a rather useful little tool that allows you to make connections to servers using the SSH transport PHP-controlled SSH shells Using SFTP/SCP to transmit files back and forth

between servers Much more!

Using SSH2

• Using SSH2 in its basic forms is a fairly straightforward process

<?php $connect = ssh2_connect(‘coggeshall.org’, 22); ssh2_auth_password($connect, ‘username’, ‘password’); $result = ssh2_exec($connect, ‘/usr/local/bin/php –i’);

while(!feof($result)) { print fgets($result, 4096); } ?>

• Note that $result is a stream which can be read from using any stream access in PHP

Using SSH2: Secure Copy

• One of the most useful bits of the ssh2 extension is the ability to secure copy files from PHP

• Very useful when transferring sensitive files to servers at run time

<?php $connect = ssh2_connect(‘coggeshall.org’, 22); ssh2_auth_password($connect, ‘username’, ‘password’);

// Sending a file ssh2_scp_send($connect, ‘/myfile.txt’, ‘/remotefile.txt’, 0755);

// Copying a file from a remote location ssh2_scp_recv($connect, ‘/remotefile.txt’, ‘localfile.txt’);?>

Some final thoughts

• So, for now those are my PECL picks I’m sure they will change over time!

• The important thing isn’t which extensions from PECL you use, but more you know to use them! Many people never even heard of PECL before

• You have to be careful though, some extensions aren’t ready for prime time

Tips on determining readiness

• When looking through PECL packages, how do you know something is of decent quality? Many previously core extensions have been moved to PECL

verbaitum• Ext/dio for example

Look for core PHP devs as maintainers• Most of these extensions will, even in beta, be quality

code Look for actively maintained extensions

• If it hasn’t left beta in two years, or only has one release, be careful

Documentation• Extensions that are documented are likely working as-

advertised PHP Bugs

• Check to see how many outstanding bugs there are for the extension

Google!• See if anyone else has been using it with any success

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Questions?

Thank you!