MARCH 2003
php|architect
VOLUME II - ISSUE 3
The Magazine For PHP Professionals
Exploring XSLT Processing Options Within PHP Turn XML into HTML with various proven methods
Beauty and Brains:
Web-Free PHP: Using PHP's CLI Interpreter
Using Flash's ActionScript, XML and PHP for Easy Multi-tier Solutions
www.phparch.com
Blazing Site Performance Using Objects and Sessions Creating an RSS Client With PHP
FreeTrade: A PHP-Based E-Commerce Solution
Plus:
Tips&Tricks, Book Reviews, Product Reviews and much more..
This copy is registered to: Liwei Cui
[email protected] Introducing the php|architect Grant Program As PHP’s importance grows on the IT scene—something that is happening every day—it’s clear that its true capabilities go well beyond what it’s being used for today. The PHP platform itself has a lot of potential as a general-purpose language, and not just a scripting tool; just its basic extensions, even discounting repositories like PEAR and PECL, provide a highquality array of functionality that most of its commercial competitors can’t afford without expensive external components. At php|a, we’ve always felt that our mission is not limited to try our best to provide the PHP community with a publication of the highest possible quality. We think that our role is also that of reinvesting in the community that we serve in a way that leads to tangible results. To that end, this month we’re launching the php|architect Grant Program, a new initiative that will see us award two $1,000 (US) grants to PHP-related projects at the end of June. Participating to the program is easy. We
invite all the leaders of PHP projects to register with our website at http://www.phparch.com/grant and submit their applications for a grant. Our goal is to provide a financial incentive to those projects that, in our opinion, have the opportunity to revolutionize PHP and its position in the IT world. In order to be eligible for the Grant Program, a project must be strictly related to PHP, but not necessarily written in PHP. For example, a new PHP extension written in C, or a new program in any language that lends itself to using PHP in new and interesting ways would also be acceptable. The only other important restriction is that the project must be released under either the LGPL, the GPL or the PHP/Zend license. Thus, commercial products are not eligible. Submit Your Project Today! Visit http://www.phparch.com/grant for more information
TABLE OF CONTENT
php|architect Departments
Features
INDEX
12 5
EDITORIAL RANTS
7
NEW STUFF
Shell Scripting with PHP (PHP CLI) by Jayesh Jain
19
FreeTrade, e-commerce for developers by Vladan Zirojevic
8
REVIEW TUTOS
32 29
REVIEW
Blazing Site Performance Using Objects and Sessions by Peter Moulding
phpLens
67
TIPS & TRICKS
41
Writing an RSS Aggregator With PHP by Marco Tabini
49
Exploring XSLT Processing Options Within PHP
by John Holmes
70
BOOK REVIEWS PHP Professional Projects Professional PHP Web Services
by Stuart Herbert
72
exit(0); Let Me Throw The First Stone
58
The Story of theBouncing Ball and XML by Sam Smith
March 2003 · PHP Architect · www.phparch.com
3
The designers of PHP offer you the full spectrum of PHP solutions
Serve More. With Less. Zend Performance Suite Reliable Performance Management for PHP
Visit www.zend.com for evaluation version and ROI calculator
Technologies Ltd.
EDITORIAL RANTS
EDITORIAL Awwww Yeah....
These were the first words I uttered after accepting an invitation to take the reins as editor-in-chief for php|architect magazine. About 3 weeks later, Marco, our fearless publisher, reminded me that I still had to write the ‘Editor’s Rants’ aritcle. This is essentially what you see at the beginning of seemingly every magazine ever published. ‘Letter from the Editor’, ‘From the Editor’s Desk’. Whatever you want to call it – it’s all the same – and as far as I can tell, it’s all pretty meaningless. Over the past few weeks I’ve read no fewer than 30 of these articles, trying to get a clue as to this article’s purpose in life. I read magazines covering every conceivable topic, formal and informal, from the politically perfect to the underground, grass-roots publications and found that these editorial columns all seem to accomplish a single goal: to make the editor look like the most pretentious, micro-managing, self-important species ever to roam the earth. Did these people lack attention as children or something? The more I read, the more I came under the suspicion that the species I had been recruited to emulate might be... well... not my cup of tea. I also couldn’t help but ask myself out loud on several occasions, ‘who reads these things?’ But alas, this is not meant to be an editorial on editorials (or a ‘metatorial’ if you will). If I’m forced to partake in this charade, then I will endeavor to make it something useful. It so happens that, being my first month at the helm, I have plenty to share with whoever is reading this, specifically with regard to my vision for php|a over the coming months. I do welcome comments on all of this, by the way:
[email protected] I’ll break my thoughts down into sections covering our current status, the near future, and the longer haul. Where We Are
From rather humble beginnings, I think php|a has accomplished much with regard to the vision of its creator – Marco Tabini. This vision was twofold, so I’ll cover them seperately. First, php|architect has become known as a reputable resource for well written, well edited documentation covering all aspects of PHP development. While I will not bore you with the laborious details of how challenging it can be to combine
March 2003 · PHP Architect · www.phparch.com
php|architect Volume II - Issue 3 March, 2003
Publisher Marco Tabini
Editor-in-Chief Brian K. Jones
[email protected] Editorial Team Arbi Arzoumani Brian Jones Peter James Marco Tabini
Graphics & Layout Arbi Arzoumani
Administration Emanuela Corso
Authors Stuart Herbert, Jayesh Jain, Peter Moulding, Dave Palmer, Sam Smith, Marco Tabini, Vladan Zirojevic
php|architect (ISSN 1705-1142) is published twelve times a year by Marco Tabini & Associates, Inc., P.O. Box. 3342, Markham, ON L3R 6G6, Canada. Although all possible care has been placed in assuring the accuracy of the contents of this magazine, including all associated source code, listings and figures, the publisher assumes no responsibilities with regards of use of the information contained herein or in all associated material.
Contact Information: General mailbox: Editorial: Subscriptions: Sales & advertising: Technical support:
[email protected] [email protected] [email protected] [email protected] [email protected] Copyright © 2002-2003 Marco Tabini & Associates, Inc. — All Rights Reserved
5
EDITORIAL editorial precision with technical savvy, I will say that this process and this accomplishment both fall under the heading of ‘non-trivial’ tasks. Certainly a very large thank you is in order for each of the many authors who collaborate with our editorial staff each month. Working together, we have been able to overcome challenges ranging from differences in opinion to differences in time zone, culture, and even language. Their time, patience, and hard work is very much appreciated. Second, php|architect continues to make great strides in establishing itself as a voice for the PHP developer community, as well as an advocate for the deployment, evolution, and progress of the PHP platform. We haven’t sought to glorify the state of PHP, nor to shun its more proprietary peers. Instead, we try to maintain a realistic focus on the use of PHP in production environments. We also take a decidedly optimistic view of the future of PHP, which at times finds itself at odds with what some of the larger names in community might have in mind. Nevertheless, we feel that the opinions of our authors, the editors, and the community are an important part in shaping any project which lists ‘open development’ as a goal. The Months Ahead
The months ahead will continue to build upon the foundation laid in the first months of our existence. The main goals in the immediate future focus largely on quality and efficiency – in other words, bringing you even better quality content whithout breaking our necks or collapsing from exhaustion in the process. To that end, there have already been improvements, tweaks and hacks put in place. First, we’ve convinced a one-time volunteer editor, Peter James, to come on staff as a full-fledged editor. Peter has proven himself to be a tireless worker and a great collaborator. He has already done wonderful work here, and he will undoubtedly leave an indelible mark upon the pages of php|architect over the coming months. Second, as further proof of our commitment to the community at large, we are very proud to announce this month the launch of a grant program to aid fledgling (or not-so-fledgling) projects to continue to progress and bring PHP into the places where no man has gone before – or at least the road less traveled. See this months pages and
March 2003 · PHP Architect · www.phparch.com
the php|architect website for more details. The Longer Term
Looking out and attempting to predict our future at such an early stage, while fun, is probably also an exercise in futility. All that can be said for sure is that there are plans of great size and great number. More huge ideas are born every day. Surprisingly, only some of the ideas belong to us ‘staffers’. The rest come from you! So far, most of the changes and adjustments we’ve made, and some which we’re working on, have come directly from our readers. We’re all constantly monitoring emails, looking in the php|architect forums, and even monitoring the PHP mailing lists in search of yet another unfulfilled need that we might be able to lend a hand to. Please keep these requests coming! There is hardly a greater compliment that can be paid to a publication than constructive feedback. In Conclusion
So now that I’ve firmly planted the image in your head of an SUV-driving, tie-wearing, cleanshaven, pretty boy editor sitting in his overstuffed couch with a $4.00 cup of coffee and a laptop, let me assure you that while I take the publication and my work seriously, I don’t take myself all that seriously at all. The reality is that I have hardly a clue how I got here. I can only be thankful for Marco’s obvious and complete insanity in choosing me for this post. I am grateful both to Marco for this opportunity, those authors with whom I’ve had (and continue to have) the distinct honor of collaborating, and the many readers who have offered their feedback and encouragement. Until next month...
6
NEW STUFF
NEW STUFF
PHP 4.3.1 Released The PHP Group has announced the release of version 4.3.1 of the PHP interpreter. The new release addresses a bug in the CGI version of the interpreter that invalidates the effectiveness of the —enable-force-cgi-redirect compile-time switch. This, in turn, makes PHP-CGI susceptible to outside hacking attacks that could result in the execution of arbitrary PHP code. For more information, visit http://ca.php.net/release_4_3_1.php ADODB 3.20 Available A new version of ADODB, the popular and efficient database abstraction library, has been released by its maintainer, PHPEverywhere blog author John Lim. ADODB 3.20 supports several new features, including abstracted capabilities for creating tables and indexes, although this functionality is still considered in its alpha stage. According to its website, available at http://php.weblogs.com/adodb, ADODB is twice as fast as PEAR-DB and 10% faster than PHP-Lib
new features, such as CVS integration, advanced project management capabilities and improved performance on all platforms. The Zend Studio 2.6 is priced starting at $195 (US). More information is available from the Zend website at http://www.zend.com. Introducing the php|architect Affiliate Program Earlier this month, we proudly announced the introduction of our new affiliate program, which pays a commission for each purchase made through our website by visitors referred from on of our partners. Participation in the program is free, and open to all websites, without any minimum requirements. You can find more information on the php|a website at https://www.phparch.com/afflogin.php. PHP Conference in Montréal
Nova: A P2P Client In PHP The Nova Project has released Nova, a peer-topeer application compatible with the popular GNUtella file-sharing network. Nova is written entirely in PHP using the PHP-GTK extension, and provides an excellent example of how PHP can be used to develop application outside the Web space. Nova, which is based on the GnucDNA library, currently supports only basic functionality and is only compatible with Windows. You can find more information at the project’s homepage (https://sourceforge.net/projects/novap2p/).
PHP Québec will hold their first PHP conference in the city of Montréal on March 20 and 21. Speakers at the event include a who’s who of the PHP community, including Zeev Suraski, Andrei Zmeivski and Rasmus Lerdorf. php|architect will also be there and our own Marco Tabini will give a presentation on PHP-based business and our experience in the world of electronic publishing. For more information, you can visit the conference’s web site at http://phpconf.phpquebec.com/.
Zend Releases Studio 2.6 PHP powerhouse Zend Technologies has release version 2.6 of their Zend Studio IDE. The new application includes several bug fixes, as well as
March 2003 · PHP Architect · www.phparch.com
php|a
7
REVIEWS
Reviewed For You
TUTOS
REVIEW
The Ultimate Team Organization Software By Marco Tabini
A
few days before writing this review (which, at the time, was another review), I had something of an epiphany. I was on the phone with a client, boasting about how organized I am, when Arbi walked by my office and laughed a typical “I know better” at me. My ego was bruised, so I wrote down a list of ways that I am organized on a piece of paper. I’d gladly show you that piece of paper if I hadn’t, er, temporarily misplaced it. As the saying goes, if you can’t blame anyone but yourself, blame the process. After all, a person can only do so much on his own. I set out to find a decent groupware application that would allow me to get more organized and, at the same time, better manage the office’s internal processes (formatting Arbi’s hard drive would have been a bonus, but I couldn’t find any applications capable of the perfect union between a calendar and that). After a bit of searching, I came across TUTOS, which stands for The Ultimate Team Organization Software. Created by German developer Gero Kohnert as an internal application for his previous employer, TUTOS has evolved into a complex groupware application that is used by the likes of Siemens. Best of all, it’s written entirely in PHP.
March 2003 · PHP Architect · www.phparch.com
The Cost: Free (released under the GPL)
Requirements: Apache You wil need one of these Databases PostgreSQL Database MySQL Database (MySQL-3.23.21-1.i386.rpm) Oracle Database Borland Interbase 5 PHP 4 (minimum php4.1)
Download Page: http://www.tutos.org/homepage/download.html
Home Page: http://www.tutos.org
Developer Background: “I started a first TUTOS like system for my former company back in 1997 or so. They still use it alot to have an overview of all their customers , software installations and different products and to support the internal Quality Managment (ISO9600). After leaving this company I started TUTOS, an enhanced system based on the same thoughts with a lot more features. On TUTOS I'm working now for more than a year and after making a first installation in my department at my current employer I think it is time to release it to the public, giving something back to the Open Source Community.”
8
REVIEWS
TUTOS
Groupware, Anyone? TUTOS is a complete groupware application in every sense. It includes a calendar, a contact management system, a bug tracking system, a product/project repository, mail capabilities, a time tracking system, an invoicing system, and much more. The system is also multilingual, supporting about fifteen languages right out of the proverbial box. For companies whose groups work in different parts of the world, TUTOS includes the ability to specify timezone information for each user profile, so that everything remains properly synchronized and meaningful to all users. Finally, the system includes a “watchlist” mechanism that makes it possible to remain up-to-date, via e-mail,
on changes to systems such as the bug tracking database or the calendar schedule. Even for a small workgroup, this “active notification” approach is a very important feature, particularly when the members of a team do not all work in the same office. User Interface and Security Features The system implements a very fine-grained permission system, thus ensuring that the administrators have every way to control access to each function. In addition, a TUTOS administrator has prompt access to all of the security settings, including his/her own. TUTOS features a colourful and easy-to-use interface that is sure to please both lovers and haters of GUIs. As
Figure 1
March 2003 · PHP Architect · www.phparch.com
9
REVIEWS
TUTOS Figure 2
you can see in Figure 1, only a minimal amount of information is kept on the left-side frame menu, leaving as much real estate as possible available for the system’s actual functionality.
TUTOS doesn't use any proprietary components that are tied to a particular architecture. Documentation, Interoperability and Limitations It’s interesting to notice that the ultimate goal of the TUTOS project is to create a portable groupware system whose interface can be written for a number of different platforms. As such, the development team has put a large amount of work into the design of the underlying data structures themselves. Naturally, that’s good news because, in addition to the PHP interface, other interfaces are likely to be developed. In fact, a KDE/Gnome version is currently in the works. From a portability perspective, TUTOS’ PHP interface doesn’t use any proprietary components that are tied to a particular architecture, and it supports several different database systems, including MySQL, PostgreSQL and Oracle. In my opinion, the system could use a bit more work as far as interoperability is concerned. In particular, I
March 2003 · PHP Architect · www.phparch.com
think that attention should be paid to integration with outside services like LDAP and/or Microsoft Exchange. This could help make TUTOS a more appealing solution for larger organizations. Since the entire system is based on PHP, however, it should be relatively simple to expand its functionality to include whatever elements one needs. The code is quite clean and well documented, so it forms a good foundation on which to build a more complex and specialized application. TUTOS includes a good deal of documentation. For the developer, the TUTOS website provides a detailed analysis of all the data structures and logical organization of the system, as well as an API reference and an installation guide. As for the end user, they get a complete contextual help system, shown in Figure 2, that includes an accurate description of what each individual screen does. Conclusion Now that I have TUTOS running on my computer, I can say with confidence that I feel more organized. As with all groupware systems, the trick to getting TUTOS into an organization is to stimulate user acceptance. After all, your average user is normally not keen on trying new things, and prefers instead to stick with the application that he or she has learned to use well. TUTOS represents an excellent groupware solution that is easy to learn and offers a wide array of functionality. It is organized in a logical fashion, provides lots of documentation, and its PHP codebase makes it easily extensible. php|a
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FEATURES
FEATURES
Shell Scripting with PHP (PHP CLI) By Jayesh Jain
PHP 4.3.0's new CLI SAPI improves greatly on the foundation laid by its CGI ancestor. Take it for a spin – no web server required!
Introduction With the introduction of version 4.2, PHP started supporting a new SAPI (Server Application Programming Interface) called CLI (Command Line Interface). This facility was introduced to help developers create small shell applications with PHP that have no dependencies on a web server. In version 4.2.0, the CLI SAPI was experimental, and had to be explicitly enabled using the —enable-cli option when running ./configure. However, with PHP 4.3.0, the CLI SAPI has been deemed stable and is therefore enabled by default. It can be explicitly disabled by specifying the —disable-cli option to ./configure. Though it was technically always possible to create independent shell-style scripts with PHP using a standalone CGI interpreter, there are a few things that make the new CLI SAPI an especially attractive and unique tool: - Unlike the CGI SAPI, no headers are written to the output. Though the CGI SAPI provides a way to suppress HTTP headers, there’s no equivalent switch to enable them in the CLI SAPI.
March 2003 · PHP Architect · www.phparch.com
- The CLI starts up in quiet mode by default, though the -q switch is kept for compatibility so that you can use older CGI scripts. - The CLI does not change the working directory to that of the script. (-C switch kept for compatibility) - Three words: Plain text errors! (no HTML formatting). In this article, we’ll discuss how to use PHP’s CLI feature to exploit the power of PHP from the command line. We’ll assume that you have a fair understanding of PHP and that PHP is installed and working properly on your computer. Most of the examples in this tutorial were tested on a Windows platform (w2k, to be precise), but should work unaltered on a Linux box. REQUIREMENTS PHP Version: 4.3 and Above O/S: Any Additional Software: N/A
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FEATURES
Shell Scripting with PHP (PHP CLI)
What is a PHP Shell Script?
Getting Started
The term ‘PHP shell script’ can cause some confusion for those who are used to traditional UNIX-style shell scripts. The reason for the confusion is that PHP, strictly speaking, does not provide a traditional interactive environment for command execution. Another source of confusion is the fact that the name of the SAPI – ‘CLI’ is also an acronym used to refer to a UNIX shell, which by definition is an interactive command execution environment! Let’s clarify this right now by simply stating that the PHP CLI is an interface to a PHP interpreter that can be accessed via the command line - not an interactive shell. In reality, ‘PHP shell scripts’ are just PHP scripts that can be run from a command line or a cron job (which will be discussed later in the article) in the same fashion as a shell or PERL script. A normal shell script consists of two main parts: the very first line, which indicates the interpreter that should be parsing the script, and the code to be executed by the interpreter. Normally, the interpreter that is specified is a UNIX shell, or some other interpreter, like PERL. However, since the creation of a PHP interpreter which can be executed directly from a shell (without the help of a web server), we can specify PHP as the interpreter for our script, and then fill the file with PHP code. For all you Windows users, PHP shell scripts are just like batch (.bat) files in MS-DOS, but with the power of the PHP programming language.
Let’s start with a small script (the most familiar one) which simply prints the words “Hello World” to the screen. Using your favorite text editor, create a text file called “world.php” in your PHP folder and enter the following text.
Finding Your PHP CLI Output on my Windows machine of the php.exe in the ‘cli’ folder was: PHP 4.3.0 (cli) (built: Dec 27 2002 05:34:00) Copyright (c) 1997-2002 The PHP Group Zend Engine v1.3.0, Copyright (c) 19982002 Zend Technologies Output on my machine of php.exe in the php root folder was:
Save the file, ensure that you have the PHP CLI executable in your path, and run the following command > php world.php Surprised to see the output, ‘Hello World’ in the command prompt instead of the web browser? Welcome to the other dimension of PHP! Note: If you are using PHP version 4.2 (or the CGI Version) you may have noticed that the following header is also in the output: X-Powered-By: PHP/4.2.3 Content-type: text/html The PHP CGI version does that by default, which can serve as an indicator that you’re using the CGI (in addition to cluing you in on the PHP version you’re running). To suppress the HTTP headers and follow along with the remaining examples, run the PHP CGI with the ‘-q’ command line flag. > php -q world.php Using the ‘-r’ option, you can also pass the PHP code to be executed to the PHP CLI directly from the command line. For example: > php -r ‘echo “Hello World\n”;’
PHP 4.3.0 (cgi-fcgi), Copyright (c) 1997-2002 The PHP Group Zend Engine v1.3.0, Copyright (c) 19982002 Zend Technologies
Will output ‘Hello World’, the same exact message as our earlier example. This is fine for small bits of code you only want to execute once. Only as the code gets larger will you need the power of a script.
This would indicate that the ‘php.exe’ file on my machine in the php root folder is actually the old CGI. For the reasons mentioned earlier comparing the CGI and CLI interpreters, and because the title of this article says ‘CLI’ in it and not ‘CGI’, I’ll be refraining from using the CGI in the examples going forward. I just wanted to point out a possible point of confusion here... so on we go!
You can redirect the output from any script to a file by running:
March 2003 · PHP Architect · www.phparch.com
> php world.php > outputfile Linux and UNIX users can also redirect the script output to another command by using the | (pipe operator). For example:
13
FEATURES
Shell Scripting with PHP (PHP CLI) Getting Interactive
> php world.php | wc -w Will return the word count of the output (in this case, it will output the number ‘2’). Conversely, you can also send output from some application or command to the php interpreter by using the pipe operator, for example: > someapp | php This might be useful if ‘someapp’ outputs PHP code which can be immediately executed by the interpreter instead of adding the overhead of first writing to a file and then calling the interpreter separately – which will then also be subject to the added overhead of opening and reading a file from disk.
PHP has always made it very easy to interact and trade data with a user via the traditional browser interface. Let’s have a look at how PHP’s ‘stream’ functions and associated constants can extend this ease to the command line interface. There are three streams available in PHP CLI. If you’re familiar with the corresponding standard UNIX device names, you’ll be right at home here, as these streams emulate the same functionality. stdin (‘php://stdin’) stdout (‘php://stdout’) stderr (‘php://stderr’) The following example will display “Hello World” in the output window using the output stream.
This time, we’ll demonstrate how to use an input stream. It will accept an input from the user, wait for the user to press the Enter key and then display the entered text.
The following example shows you how to output text to an error stream.
- Shell scripts are commonly used to automate day-to-day administration tasks. Figure 1
March 2003 · PHP Architect · www.phparch.com
14
FEATURES
Shell Scripting with PHP (PHP CLI)
To make accessing and moving data around in a shell environment simpler, PHP has added the following constants. Again, for UNIX users, these names should look familiar. In UNIX, these typically map to the keyboard (STDIN) and the screen (STDOUT and STDERR) by default. Using Arguments in Scripts Anyone who has experience writing shell or PERL scripts would probably consider the PHP CLI completely useless if the scripts weren’t able to handle arguments passed to it from the command line. The CLI handles this with the use of the $argv and $argc variables. All of the arguments passed to your script are stored in a zero based global array variable $argv. Another global variable, $argc, holds the number of arguments passed to the script (everyone coming from a C/C++ background, should be familiar with this practice). Here is the code, which displays the total number of arguments passed as well as the arguments:
STDIN An already opened stream to stdin. You don’t have to open it with: $stdin = fopen('php://stdin', 'r'); STDOUT An already opened stream to stdout. You don’t have to open it with: $stdout = fopen('php://stdout', 'w'); STDERR An already opened stream to stderr. You don’t have to open it with: $stderr = fopen('php://stderr', 'w'); Here is an example of how to use a stream with constants: For users of version 4.2, you’ll need to add these additional lines to the top of your script in order for the above example to work: define('STDIN',fopen("php://stdin","r")); define('STDOUT',fopen("php://stdout","w") define('STDERR',fopen("php://stderr","w")
Figure 2
March 2003 · PHP Architect · www.phparch.com
15
FEATURES Assuming this is stored in a file argument.php you could test this script by running: > php argument.php arg1 arg2 Refer to Figure 2 for sample output Important : You can use $argc and $argv in the manner described above only if you have both the register_globals and register_argc_argv settings in php.ini set to ‘on’. As of PHP version 4.3, register_globals is set to ‘off’ by default. You should do your best to write your scripts so that they do not require register_globals to be on, to avoid possible security issues in your incoming form variables. You can still use $argv and $argc if register_globals is set to ‘off’. Just use the following code: $argc = $_SERVER['argc']; $argv = $_SERVER['argv'];
Using External commands in Scripts In order to run any external command from the script, we will have to use the php function shell_exec. Shell_exec will execute a command via the shell and return complete output as a string.
For Linux/UNIX Users As we’ve discussed, the PHP executable runs independently of the web server. An added benefit of using this interface for your scripting is that it makes your scripts more portable than using, say, ‘/bin/bash’. Using ‘#!/usr/bin/php’ at the top of your script will allow you to invoke the PHP interpreter on a Linux machine, and on Windows, this line will be skipped over to get to the PHP code below. Now you can write in your familiar Linux environment, and still deploy to Windows. Tip: Don’t forget that Linux won’t let you do anything until the script has its ‘execute’ bit set. Assuming your script is called ‘testscript.php’, you can just ‘cd’ to the directory where the script lives and type: > chmod +x testscript.php Once you have set the executable attribute, you can execute the file like this:
...using PHP's CLI interface makes your scripts more portable than using, say, '/bin/bash'. For Windows Users: Configuring Windows to Execute PHP Scripts To run PHP scripts on your Windows machine, you’ll need to associate the PHP files with the PHP interpreter. To do this, open Windows Explorer, click on the tools menu and select ‘folder options’. Click on the ‘File Types’ tab and select the ‘New’ button. Type ‘.php’ in as the file extension, and click OK.
> ./testscript.php March 2003 · PHP Architect · www.phparch.com
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FEATURES
Shell Scripting with PHP (PHP CLI) Refer to Figure 3
You can also register files with extension ‘.php3’ or ‘.php4’ in the same fashion mentioned above.
Select the PHP entry in the ‘Registered File Types’ list box, click the ‘Advanced’ button, click ‘new’ and type ‘Run’ in the Action box. In the ‘Application Used to Perform Actions’ box, type C:\PHP\PHP.exe “%1” %* (change the PHP path if it’s different on your machine. Note that ‘%*’ is used to send any command line arguments). Click ‘OK’, ‘OK’ again and then the ‘Close’ button. Your Windows machine is now configured to run PHP Scripts. Just double click on any PHP file in Windows Explorer to run it.
More Information There are certain php.ini directives, which are overridden by the CLI SAPI because they do not make sense in shell environments: a) html_errors = FALSE As the output of the PHP CLI does not go to a browser, there is no need to echo HTML tags hence this directive defaults to FALSE.
Refer to Figure 4 Figure 3
March 2003 · PHP Architect · www.phparch.com
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FEATURES
Shell Scripting with PHP (PHP CLI)
b) implicit_flush = TRUE All the output coming from output commands need to be shown instantly and should not be cached. As a result, this directive is defaulted to TRUE. c) max_execution_time = 0 (unlimited) Because the PHP runs in the shell environment and often does tasks which take a longer time, the max_execution_time is defaulted to unlimited.
Using the MySQL Database in Your Scripts You can connect to MySQL database exactly the same way as you do in your normal php scripts except you should not use HTML tags as the output is not sent to the browser. Here is a simple example, which connects to a MySQL database and lists the username field for all records in the user table.
