章 48. Installation

This section holds common questions about the way to install PHP. PHP is available for almost any OS (except maybe for MacOS before OSX), and almost any web server.

To install PHP, follow the instructions in the INSTALL file located in the distribution. Windows users should also read the install.txt file. There are also some helpful hints for Windows users here.

1. Unix/Windows: Where should my php.ini file be located?
2. Unix: I installed PHP, but every time I load a document, I get the message 'Document Contains No Data'! What's going on here?
3. Unix: I installed PHP using RPMS, but Apache isn't processing the PHP pages! What's going on here?
4. Unix: I installed PHP 3 using RPMS, but it doesn't compile with the database support I need! What's going on here?
5. Unix: I patched Apache with the FrontPage extensions patch, and suddenly PHP stopped working. Is PHP incompatible with the Apache FrontPage extensions?
6. Unix/Windows: I have installed PHP, but when I try to access a PHP script file via my browser, I get a blank screen.
7. Unix/Windows: I have installed PHP, but when try to access a PHP script file via my browser, I get a server 500 error.
8. Some operating systems: I have installed PHP without errors, but when I try to start apache I get undefined symbol errors:
[mybox:user /src/php4] root# apachectl configtest
 apachectl: /usr/local/apache/bin/httpd Undefined symbols:
  _compress
  _uncompress
9. Windows: I have installed PHP, but when I to access a PHP script file via my browser, I get the error:
cgi error:
 The specified CGI application misbehaved by not
 returning a complete set of HTTP headers.
 The headers it did return are:
10. Windows: I've followed all the instructions, but still can't get PHP and IIS to work together!
11. When running PHP as CGI with IIS, PWS, OmniHTTPD or Xitami, I get the following error: Security Alert! PHP CGI cannot be accessed directly..
12. How do I know if my php.ini is being found and read? It seems like it isn't as my changes aren't being implemented.

By default on UNIX it should be in /usr/local/lib which is install-path /lib. Most people will want to change this at compile-time with the --with-config-file-path flag. You would, for example, set it with something like:

--with-config-file-path=/etc
And then you would copy php.ini-dist from the distribution to /etc/php.ini and edit it to make any local changes you want.

On Windows the default path for the php.ini file is the Windows directory. If you're using the Apache webserver, php.ini is first searched in the Apaches install directory, e.g. c:\program files\apache group\apache. This way you can have different php.ini files for different versions of Apache on the same machine.

See also the chapter about the configuration file.

Due to the way PHP 3 built, it is not easy to build a complete flexible PHP RPM. This issue is addressed in PHP 4. For PHP 3, we currently suggest you use the mechanism described in the INSTALL.REDHAT file in the PHP distribution. If you insist on using an RPM version of PHP 3, read on...

The RPM packagers are setting up the RPMS to install without database support to simplify installations and because RPMS use /usr/ instead of the standard /usr/local/ directory for files. You need to tell the RPM spec file which databases to support and the location of the top-level of your database server.

This example will explain the process of adding support for the popular MySQL database server, using the mod installation for Apache.

Of course all of this information can be adjusted for any database server that PHP supports. We will assume you installed MySQL and Apache completely with RPMS for this example as well.



  • Then get the source rpm and INSTALL it, NOT --rebuild



  • Then edit the /usr/src/redhat/SPECS/mod_php3.spec file

    In the %build section add the database support you want, and the path.

    --with-mysql=/usr \
    
    The %build section will look something like this:
    ./configure --prefix=/usr \
        --with-apxs=/usr/sbin/apxs \
        --with-config-file-path=/usr/lib \
        --enable-debug=no \
        --enable-safe-mode \
        --with-exec-dir=/usr/bin \
        --with-mysql=/usr \
        --with-system-regex
    


  • Once this modification is made then build the binary rpm as follows:

    rpm -bb /usr/src/redhat/SPECS/mod_php3.spec
    


  • rpm -ivh /usr/src/redhat/RPMS/i386/mod_php3-3.0.5-2.i386.rpm
    


Make sure you restart Apache, and you now have PHP 3 with MySQL support using RPM's. Note that it is probably much easier to just build from the distribution tarball of PHP 3 and follow the instructions in INSTALL.REDHAT found in that distribution.

This error message means that PHP failed to output anything at all. To get to see a sensible error message, from the command line, change to the directory containing the PHP executable (php.exe on Windows) and run php -i. If PHP has any problems running, then a suitable error message will be displayed which will give you a clue as to what needs to be done next. If you get a screen full of html codes (the output of the phpinfo() function) then PHP is working.

Once PHP is working at the command line, try accessing the script via the browser again. If it still fails then it could be one of the following:

  • File permissions on your PHP script, php.exe, php4ts.dll, php.ini or any PHP extensions you are trying to load are such that the anonymous internet user ISUR_ machinename cannot access them.

  • The script file does not exist (or possibly isn't where you think it is relative to your web root directory). Note that for IIS you can trap this error by ticking the 'check file exists' box when setting up the script mappings in the Internet Services Manager. If a script file does not exist then the server will return a 404 error instead. There is also the additional benefit that IIS will do any authentication required for you based on the NTLanMan permissions on your script file.

You must set the cgi.force_redirect directive to 0. It defaults to 1 so be sure the directive isn't commented out (with a ;). Like all directives, this is set in php.ini

Because the default is 1, it's critical that you're 100% sure that the correct php.ini file is being read. Read this faq for details.

To be sure your php.ini is being read by PHP, make a call to phpinfo() and near the top will be a listing called Configuration File (php.ini). This will tell you where PHP is looking for php.ini and whether or not it's being read. If just a directory PATH exists than it's not being read and you should put your php.ini in that directory. If php.ini is included within the PATH than it is being read.

If php.ini is being read and you're running PHP as a module then be sure to restart PHP after making changes to php.ini