View source for Running PHP Scripts on the CS Webservers

The multi-user nature of the CS webservers require us to run PHP in a slightly uncommon way.  We run PHP as a CGI using Apache's [https://httpd.apache.org/mod_fcgid/ mod_fcgid] [https://en.wikipedia.org/wiki/FastCGI FastCGI] module.  That means that some common ways to use PHP need to be done slightly differently in our environment.  These differences are documented below.

== Files in Your Home Directory ==

There is a <tt>'''php-cgi'''</tt> script in your <tt>~/public_html/cgi-bin</tt> directory.  This is the script that runs the ''PHP CGI'' interpreter for you.  Apache is told about this script by the <tt>'''FcgidWrapper'''</tt> directive in your <tt>'''~/public_html/.htaccess'''</tt> file.

''Changing either of these files should be done with care, as doing so could prevent PHP from working for your webpages.''

== The phpinfo() Function ==

The <code>phpinfo()</code> function is disabled on our webservers.  It discloses a significant amount of information about our servers that people on the public Internet don't need.  If you have a question about availability of particular PHP modules, please feel free to {{mailto|support|email us}} and ask.

== Apache AddType Directives ==

The CS webservers treat any file that has a <tt>'''.php'''</tt> extension as a PHP script.  In some cases, you might want files with other extensions to also be treated as PHP scripts. 

Most documentation on the web describes how to use the [https://httpd.apache.org/docs/2.2/mod/mod_mime.html#AddType AddType] Apache directive in your <tt>'''.htaccess'''</tt> file for this, and that directive usually looks like this:

<pre class="bad">AddType application/x-httpd-php .html</pre>

''However,'' for our websites, ''instead of AddType,'' you will need to use the [https://httpd.apache.org/docs/2.2/mod/mod_mime.html#addhandler AddHandler] directive to process the file as a FastCGI script and give the ''full path'' to your <tt>'''php-cgi'''</tt> script to run it.  For example, a ''grad'' account might use the following to execute HTML files at PHP scripts:

<pre class="good">AddHandler fcgid-script .html
FcgidWrapper /users/YOUR-ACCOUNT-HERE/public_html/cgi-bin/php-cgi .html</pre>

A ''ugrad'' account might use the following to execute files with a "<code>.p</code>" extension as PHP scripts:

<pre class="good">AddHandler fcgid-script .p
FcgidWrapper /home/YOUR-ACCOUNT-HERE/public_html/cgi-bin/php-cgi .p</pre>

== Apache ForceType Directives ==

Another way to force a particular file or files to be treated as PHP is to use a [https://httpd.apache.org/docs/2.2/mod/core.html#files <Files>] or [https://httpd.apache.org/docs/2.2/mod/core.html#directory <Directory>] section in your <tt>'''.htaccess'''</tt> file to target those files specifically.  The customary documentation on the web uses the [https://httpd.apache.org/docs/2.2/mod/core.html#ForceType ForceType] directive for this:

<pre class="bad"><Files quux.foo>
   ForceType application/x-httpd-php
</Files></pre>

''However,'' for our websites, ''instead of ForceType,'' you have to use the [https://httpd.apache.org/docs/2.0/mod/core.html#sethandler SetHandler] directive along with the ''full path'' to your <tt>'''php-cgi'''</tt> script.  For a ''grad'' example:

<pre class="good"><Files quux.foo>
  SetHandler fcgid-script
  FcgidWrapper /users/YOUR-ACCOUNT-HERE/public_html/cgi-bin/php-cgi
</Files></pre>

''ugrad'' accounts, need to use a slightly different path:

<pre class="good"><Files quux.foo>
  SetHandler fcgid-script
  FcgidWrapper /home/YOUR-ACCOUNT-HERE/public_html/cgi-bin/php-cgi
</Files></pre>


== If PHP Doesn't Work ==

First, check to make sure your <tt>~/public_html/.htaccess</tt> and <tt>~/public_html/cgi-bin/php-cgi</tt> files exist and have the right contents and permissions.

For ''grad'' accounts, <tt>~/public_html/.htaccess</tt> should contain the following line:

 FcgidWrapper /users/''your-account''/public_html/cgi-bin/php-cgi .php

For ''ugrad'' accounts, <tt>~/public_html/.htaccess</tt> should contain the following line:

 FcgidWrapper /home/''your-account''/public_html/cgi-bin/php-cgi .php

'''Make sure you replace "''your-account''" with your actual account name.'''

<tt>~/public_html/cgi-bin/php-cgi</tt> should have the following contents:

 #!/bin/sh
 exec /usr/bin/php-cgi

[[File Permissions for Webpages|All of the files need to have specific permissions.]]  Run the following commands from a terminal window to set their permissions appropriately:

 chmod 0701 ~
 chmod 0701 ~/public_html
 chmod 0604 ~/public_html/.htaccess
 chmod 0701 ~/public_html/cgi-bin
 chmod 0700 ~/public_html/cgi-bin/php-cgi

If you are still having problems, please email [mailto:support@cs.jhu.edu support@cs.jhu.edu] for assistance.

[[Category:Webpages_and_Webservices]]