It makes sense then that at the same time the popularity of the web was exploding, people were looking for ways to generate or 'script' HTML just before the page is sent to the requesting client. In 1995 Rasmus Lerdorf created a Perl CGI script to log the people that were visiting his web-based resume. Thus the content of his page was automatically updated or 'dynamic,' and people wanted to know how he did it. Thus he began giving away his “Personal Home Page” tools. In 1996 after a job in Toronto, he released the second version, called PHP/FI which he created to access a library database from a web interface. The immensely popular version 3 was released with the assistance of Zeev Suraski and Andi Gutmans, and version 4 came out in May of this year. PHP continues to be a popular and open source method for dynamically generating web content on the server as well as interacting with various database formats. It has also grown popular do to its incorporation with the Apache web server. As a result, the webserver today processes and generates HTML as much it responds to and serves requests for pages.
I knew the Apache install would be pretty straightforward, and I’ve been interested in working with some server-side scripting languages, like PHP and Perl, so I decided to combine the installation of Apache and PHP into one project.
Step 1) Install flex and bison. This will avoid PHP ./configure problems that I encountered in Step 3 below. I installed:
# rpm –ivh bison-1.28-2.i386.rpm
# rpm –ivh flex-2.5.4a-9-i386.rpm
Step 2) Install Apache with mod.so, which allows for Dynamic Shared Objects (DSO’s):
# ./configure --enable-module=so
# make
# make install
At this point, Apache is installed in /usr/local/apache/ and can be started. However, before we do that we need to install PHP.
Step 3) Install PHP with MySQL and APXS. MySQL is relational database management system (RDBMS). By including it in the PHP install, it allows for web-database connectivity in the future. APXS stands for APache eXtenSion tool, used for building Apache modules.
The PHP INSTALL file suggests using the following line to configure PHP for compilation:
# ./configure --with-mysql --with-apxs
However, after getting the following error:
checking for Apache module support via DSO through APXS... no
checking for Apache module support... yes - Apache 1.3.x
configure: error: Please run Apache\'s configure or src/Configure
program once and try again
I read back over the PHP INSTALL instructions and realized that I’d need to give the path to APXS---which I found using the locate command:
# locate apxs
/home/jwatt/apache_1.3.12/src/support/apxs.8
/home/jwatt/apache_1.3.12/src/support/apxs.pl
/home/jwatt/apache_1.3.12/src/support/apxs
/usr/local/apache/bin/apxs
/usr/local/apache/man/man8/apxs.8
First I tried this:
# ./configure --with-mysql --with-apxs=/usr/local/apache/bin/
Which didn’t work so I tried this:
# ./configure --with-mysql --with-apxs=/usr/local/apache/bin/apxs
which did work. [./configure went on to give me an error because I didn’t have flex installed, and it gave me a warning because I didn’t have bison installed---hence Step 1]
I finished the PHP install successfully with:
# make
# make install
The final task to complete the PHP installation involves copying the PHP configuration file from php-4.0.2/ to it’s permanent home:
# cp php.ini-dist /usr/local/lib/php.ini
In httpd.conf:
# Dynamic Shared Object (DSO) Support
LoadModule php4_module libexec/libphp4.so # critically important
for PHP to work
### Section 2: 'Main' server configuration
Port 80
ServerName http://xxx.xxx.xxx.xxx/
# http://152.2.38.210/ in my case
# And for PHP 4.x, use:
AddType application/x-httpd-php .php
# critically important for PHP to work
The LoadModule directive is necessary to tell Apache where to find PHP module or DSO. The AddType line is necessary to tell Apache what type of files should be parsed by PHP, in this case, .php files.
In php.ini:
; Language Options ;
engine =
On ; Enable the PHP scripting language engine
under Apache
short_open_tag = On
; allow the <? tag. otherwise, only <?php and <script> tags
are recognized.
The above two directives are the defaults after installation, however, if PHP does appear to be working, it pays to make sure they are both set to "On". The first enables the PHP engine, the second allows for the ubiquitous <? ?> tags.
PHP example 1:
<!-- The PHP tag below generates a lot of diagnostic PHP information
in HTML format -->
<?phpinfo()?>
If PHP isn’t working, a web browser might just present the .php file as text, exposing the PHP tag. Or perhaps the web browser might prompt you to download the file, not knowing how to display it. In either case this is a sign that PHP is not parsing the PHP tag. Assuming that all the steps above have been followed, and that there were no unexpected complications along the way, the first solution to take would be to restart the Apache webserver in order for those crucial additions to the httpd.conf file to be activated. You can do this by typing
# /usr/local/apache/bin/apachectl restart
Then go back and make sure all of the changes in the httpd.conf file were made correctly and are uncommented. If all else fails, start over and reinstall Apache and PHP, making sure to pay close attention to the messages that scroll by.
On the other hand, if PHP is parsing .php files, then the PHP document above, should look like this: (screen shot)
Ok, so PHP is working, now what can it do? I culled the following example below from a tutorial on the Zend website. Notice that the entire file is enclosed in <? ?> tags. $html is a string variable that PHP concatenates onto using the .= operator. The for loop generates the majority of the content, in this case the squares of the numbers 0 to 9--with the surrounding HTML tags--that create a table in which to hold the values. The final line before the ?> end tag echoes the $html variable out, which is what the browser uses to construct the output for the user.
PHP example 2:
<?
$html = '<html><body><table>';
$html .= '<tr><td>number</td><td>square</td></tr>';
for ( $i=0 ; $i<10 ; $i++) {
$square = $i * $i;
$html .= '<tr><td>' . $i . '</td><td>'
. $square . '</td></tr>';
}
$html .= '</table></body></html>';
echo $html
?>
Produces this HTML output (line breaks added for readability):
<html><body><table><tr><td>number</td><td>square</td></tr>
<tr><td>0</td><td>0</td></tr><tr><td>1</td><td>1</td></tr>
<tr><td>2</td><td>4</td></tr><tr><td>3</td><td>9</td></tr>
<tr><td>4</td><td>16</td></tr><tr><td>5</td><td>25</td></tr>
<tr><td>6</td><td>36</td></tr><tr><td>7</td><td>49</td></tr>
<tr><td>8</td><td>64</td></tr><tr><td>9</td><td>81</td></tr>
</table></body></html>
Which the browser renders as:
number square
0 0
1 1
2 4
3 9
4 16
5 25
6 36
7 49
8 64
9 81
Though this example is elementary, it hints at PHP's potential power when it comes to reading through records in a database and outputting the results in HTML for the browser to render.
AddType application/x-httpd-php .php
would only have to be changed to this:
AddType application/x-httpd-php .php .html
However, this simple adjustment caused me unknown frustration. When I made this change, PHP continued to parse the .php version of my document, but when I pointed my browser to the .html version of the same exact file, the browser didn't know what to do. Both Netscape and Internet Explorer would attempt to download the file, which as I discovered, was unparsed. I spent several hours searching for a solution via www.google.com, www.deja.com, www.phpbuilder.com, etc. etc. Several other mentioned this problem, but no solutions ever came of their postings. After several hours of researching this infinitesimally small issue, I had an epiphany looking at the lines in the httpd.conf file for server-side includes (SSI):
AddType text/html .shtml
AddHandler server-parsed .shtml
I noticed that it took both lines to tell Apache what to do with .shtml files. The first defined .shtml as type text/html and the second told Apache what to do with .shtml files. It occurred to me that perhaps the PHP AddType line above didn’t know what an .html file was, and maybe I should define .html just like .shtml is defined. Thus I added these lines to my httpd.conf file:
AddType text/html .html
AddType application/x-httpd-php .php .html
I restarted the server and it worked!
INLS 183 Project 2: Apache_1.3.12 and PHP-4.0.2 script file
