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Create a file named hello.php and put it
in your web server's root directory (DOCUMENT_ROOT)
with the following content:
Example 2-1. Our first PHP script: hello.php |
<html>
<head>
<title>PHP Test</title>
</head>
<body>
<?php echo '<p>Hello World</p>'; ?>
</body>
</html>
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Use your browser to access the file with your web server's URL, ending
with the "/hello.php" file reference. When developing locally this
URL will be something like http://localhost/hello.php
or http://127.0.0.1/hello.php but this depends on the
web server's configuration. If everything is configured correctly, this
file will be parsed by PHP and the following output will be sent to
your browser:
<html>
<head>
<title>PHP Test</title>
</head>
<body>
<p>Hello World</p>
</body>
</html> |
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This program is extremely simple and you really did not need to use
PHP to create a page like this. All it does is display:
Hello World using the PHP echo()
statement. Note that the file does not need to be executable
or special in any way. The server finds out that this file needs to be interpreted
by PHP because you used the ".php" extension, which the server is configured
to pass on to PHP. Think of this as a normal HTML file which happens to have
a set of special tags available to you that do a lot of interesting things.
If you tried this example and it did not output anything, it prompted
for download, or you see the whole file as text, chances are that the
server you are on does not have PHP enabled, or is not configured properly.
Ask your administrator to enable it for you using the
Installation chapter
of the manual. If you are developing locally, also read the
installation chapter to make sure everything is configured
properly. Make sure that you access the file via http with the server
providing you the output. If you just call up the file from your file
system, then it will not be parsed by PHP. If the problems persist anyway,
do not hesitate to use one of the many
PHP support options.
The point of the example is to show the special PHP tag format.
In this example we used <?php to indicate the
start of a PHP tag. Then we put the PHP statement and left PHP mode by
adding the closing tag, ?>. You may jump in
and out of PHP mode in an HTML file like this anywhere you want. For more
details, read the manual section on the
basic PHP syntax.
A Note on Text Editors:
There are many text editors and Integrated Development Environments (IDEs)
that you can use to create, edit and manage PHP files. A partial list of
these tools is maintained at PHP Editors
List. If you wish to recommend an editor, please visit the above
page and ask the page maintainer to add the editor to the list. Having
an editor with syntax highlighting can be helpful.
A Note on Word Processors:
Word processors such as StarOffice Writer, Microsoft Word and Abiword are
not optimal for editing PHP files. If you wish to use one for this
test script, you must ensure that you save the file as plain
text or PHP will not be able to read and execute the script.
A Note on Windows Notepad:
If you are writing your PHP scripts using Windows Notepad, you will need
to ensure that your files are saved with the .php extension. (Notepad adds
a .txt extension to files automatically unless you take one of the
following steps to prevent it.) When you save the file and are prompted
to provide a name for the file, place the filename in quotes
(i.e. "hello.php"). Alternatively, you can click on the
'Text Documents' drop-down menu in the 'Save' dialog box and change the setting
to "All Files". You can then enter your filename without quotes.
Now that you have successfully created a working PHP script, it is
time to create the most famous PHP script! Make a call to the
phpinfo() function and you will see a lot of useful
information about your system and setup such as available
predefined variables,
loaded PHP modules, and configuration
settings. Take some time and review this important information.
Example 2-2. Get system information from PHP |
User Contributed Notes
Your first PHP-enabled page
onebadscrivener at gmail dot com
17-Jan-2005 08:25
OS X users editing in TextEdit will need to make sure their TextEdit preferences are set to allow plain text files. Under the TextEdit pull-down menu, choose PREFERENCES, then under NEW DOCUMENT ATTRIBUTES in the window that pops up, click PLAIN TEXT.
Then, in the section of that same window called "saving," DESELECT "append .txt extension to plain text files." This will allow you to save your files with a .php extension.
Then close the PREFERENCES window. You're good to go.
jo at durchholz dot org
30-Sep-2004 08:53
If PHP is running under Apache, there are very different ways to tell Apache what's a PHP script and whether it should be executed. If you can, locate the httpd.conf and look for the appropriate settings; if you can't, ask your site administrator.
The options are:
1) Make Apache interpret any PHP files it finds and serve them like HTML. This kind of set-up is rare, as it is extremely unsafe. PHP "safe mode" is intended to give some measure of protection in such situations, but it doesn't even approach that of setup (3b), below (safe mode is over-restrictive in some areas and not restrictive enough in others, and too many PHP scripts will break in safe mode anyway, so I decided against it - YMMV).
2) Make Apache interpret PHP files only if they are found in some specific URL area (usually /cgi-bin/whatever). This doesn't help in protecting different users from each other, but it makes it more obvious if, say, a file upload would overwrite a script. (It's not a real protective measure though. File uploads shouldn't be permitted except into specially designated data directories with a .htaccess file that disallows script execution of any kind. Actually this applies to any kind of file creation, e.g. many Wikis allow the user to type in a topic name and will create a text file with that name - so the directory in which the name is created should be made non-executable.)
3) Make Apache hand over .php, .sh, .pl etc. etc. to the Unix shell for interpretation. This has the advantage that Apache can use the "suEXEC" mechanism, which allows it to impersonate some other user than the standard "nobody" or "www-data". For example, if multiple users are allowed to create PHP scripts on the same server, the server administrator will create a separate user account for each, and have Apache impersonate the appropriate account. Unfortunately, this setup gives up a large amount of efficiency, which means that the hoster has to set up a larger machine for the same load. In other words, hosting accounts will be a bit more expensive but *far* more safe.
3a) A badly-configured setup of this kind will require that you insert a line like "#! /usr/bin/php4" at the top of each PHP file. Of course, this is simply too much work for even modest amounts of PHP on a site, but some (few) sites require this anyway.
3b) A better-configured setup will recognize file types from the file extension (just as Windows does it). If you have a (3a)-style setup and know or suspect your provider has a Linux box running, talk to him about the binfmt_misc extension. It requires about a hour to install properly and (possibly) a kernel recompilation (that's another hour or two if they are just running preinstalled boxes, and a near-zero overhead if they're installing their machines anyway).
Most sites combine setup (2) with safe mode. In that case, do a regular backup of everything that you have on the server, since your site is open to attacks from script kiddies that live on the same machine. (Source Forge had incidents of that kind.)
(Note that this kind of problem applies to Perl scripts, or any kind of scripting that can create or overwrite files. For example, the TWiki site on SourceForge got clobbered by this at least once - well, SourceForge is particularly vulnerable to this because anybody with a browser and pretending to do open source development will be allowed to upload CGI scripts.)
funkydruid at optusnet dot com dot au
09-Sep-2004 08:47
Curtis
10-Aug-2004 05:47
Expansion on saving w/ notepad/wordpad: (tested on XP; but should work on 2000,NT, and 98)
You can associate the .php file extension w/ Windows w/o going into the registry.
Open up My Computer or MSIE in file mode. Go to folder options > File types tab. Now click new. Add the extension as PHP or php. If you can't find the PHP application in the dropdown list under advanced, just go OK, for now. At least the extension is in place.
Now, try and create a php file by using the directions from this page of the PHP tutorial (should save it with the rest of your HTML files, i.e. your DocumentRoot). If you go to view your php file listed in the directory, and you see that it's still a .txt file, right-click the icon to see if you can locate "open with." If so, you should be able to browse for the appropriate file, which should be at (may vary, depending on where you installed PHP):
C:\PHP\php.exe
Click that as the default program, and the PHP logo should appear on all your scripts, and no problems saving should occur w/ any program.
Good luck.
john at php dot com
01-Jan-2004 10:45
att. to adobe golive users,
golive is not widely seen as a comfortable php source code editor, as its use you might find it difficult but theres never a "no";
to work with php you must first realize the dynamic wizard (and its still more important if youre building a website)
full-house with adobe golive cs, which is the newest one and it has improved in some aspects which newbies cannot see,
Slowpoke
10-Sep-2003 03:27
Mac Users
For those using MAC OSX, you've already got an Apache Server, you just need to switch it on.
Go to: preferences>sharing and turn 'personal web-sharing' on. Then open up you browser and go to http://localhost/ and you should get a screen telling you all about your server. Well done, your Apache Server is switched on and working.
There's a little more to it that that though. You may need to set up PHP and mySQL. I've taken the liberty of throwing you a very useful link that should get your server up and runninig with everything you need, as well as giving you a brief insight into how useful PHP and mySQL can be. It's a big'un!
http://www.macdevcenter.com
/pub/a/mac/2003/04/04/
apache_jaguar_pt1.html
(I had to break this to get it posted I'm afraid)
Thats all for now,
chow chow
Slowpoke
ryan420 at earthling dot net
03-Feb-2003 05:18
Note on permissions of php files: You don't have to use 'chmod 0755' under UNIX or Linux; the permissions need not be set to executable. Again, this is more like a html file than a cgi script. The only mandatory requirement is that the web server process has read access to the php file(s). With many Linux systems, it is popular for Apache to run under the 'apache' account. Given that HTML and other web files, like php, are often owned by user 'root' and group 'web' (or another similar group name), acceptable permissions might be those achieved with 'chmod 664' or 'chmod 644'. The web server process, running under the 'apache' account, will inherit read only permissions. The 'apache' account is not root and is not a member of the 'web' group, so the "other" portion of the permissions (the last "4") applies.
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A simple tutorial