Linux – Configuring PHP for existing MySQL installation

I am taking over basic administration duties for a former tech employee for my client. On a CentOS server I have the following:

Apache, PHP and MySQL. He had PHP installed but did not configure it with the MySQL extension (I assume because the server was only hosting a rails-based website).

So I need to reconfigure PHP to use the MySQL extension. Here is the current PHP configure (from phphinfo(); ):

'./configure' '--build=i686-redhat-linux-gnu' '--host=i686-redhat-linux-gnu' '--
target=i386-redhat-linux-gnu' '--program-prefix=' '--prefix=/usr' '--exec-prefix=/usr' '--
bindir=/usr/bin' '--sbindir=/usr/sbin' '--sysconfdir=/etc' '--datadir=/usr/share' '--
includedir=/usr/include' '--libdir=/usr/lib' '--libexecdir=/usr/libexec' '--
localstatedir=/var' '--sharedstatedir=/usr/com' '--mandir=/usr/share/man' '--
infodir=/usr/share/info' '--cache-file=../config.cache' '--with-libdir=lib' '--with-config-
file-path=/etc' '--with-config-file-scan-dir=/etc/php.d' '--disable-debug' '--with-pic' '--
disable-rpath' '--without-pear' '--with-bz2' '--with-curl' '--with-exec-dir=/usr/bin' '--
with-freetype-dir=/usr' '--with-png-dir=/usr' '--enable-gd-native-ttf' '--without-gdbm' '--
with-gettext' '--with-gmp' '--with-iconv' '--with-jpeg-dir=/usr' '--with-openssl' '--with-
png' '--with-pspell' '--with-expat-dir=/usr' '--with-pcre-regex=/usr' '--with-zlib' '--
with-layout=GNU' '--enable-exif' '--enable-ftp' '--enable-magic-quotes' '--enable-sockets' 
'--enable-sysvsem' '--enable-sysvshm' '--enable-sysvmsg' '--enable-track-vars' '--enable-
trans-sid' '--enable-yp' '--enable-wddx' '--with-kerberos' '--enable-ucd-snmp-hack' '--
with-unixODBC=shared,/usr' '--enable-memory-limit' '--enable-shmop' '--enable-calendar' '--
enable-dbx' '--enable-dio' '--with-mime-magic=/usr/share/file/magic.mime' '--without-
sqlite' '--with-libxml-dir=/usr' '--with-xml' '--with-system-tzdata' '--with-
apxs2=/usr/sbin/apxs' '--without-mysql' '--without-gd' '--without-odbc' '--disable-dom' '--
disable-dba' '--without-unixODBC' '--disable-pdo' '--disable-xmlreader' '--disable-
xmlwriter'

You can see that he has –without-mysql in there.

When you configure PHP to use –with-mysql, you have to specify the path to mysql right? Or the mysql source? Or something like that? Something like this:

--with-mysql=/usr/local/mysql

The problem with this existing setup is that MySQL is already installed, except I don't know where its installed at… I know that there is /etc/init.d/mysqld. I also found the following directories:

/usr/lib/mysql/
/usr/include/mysql/
/usr/share/mysql/

Can anyone point me in the right direction here? I just don't know what directory to use with –with-mysql in the PHP configuration.

UPDATE

Okay so I got PHP reconfigured and remade and installed. Now when I restart Apache I get the following:

[warn] module php5_module is already loaded, skipping

Is this because php was already running on the server before? I looked at the httpd.conf and it only has one instance of php5_module getting loaded…

However, when now view the phpinfo(); it shows the PHP being used in the new updated version that I just configured/installed.

Also, the phpinfo(); shows mysql as being used, however when I attempt to install say, WordPress (which uses MySQL), WordPress is giving this error:

Your PHP installation appears to be missing the MySQL extension which is required by WordPress.

Where should I be looking now?

UPDATE #2

Still no solution so far. I've gone through the configuration of PHP to include Mysql and the phpinfo(); (yes I'm using a file.php to view this) shows –with-mysql=shared,/usr (per another users suggestion below). PHP still isn't recognizing MySQL extension as being in the configuration however.

I just don't understand what is the path that you are supposed to put at the end of –with-mysql= ? I have the following directories I've found:

/usr/bin/ contains:
mysql (executable?)

/usr/lib/mysql/ contains:
libdbug.a    libmyisammrg.a      libmysqlclient_r.so         libmysqlclient.so         libmystrings.a  mysqlbug
libheap.a    libmysqlclient.a    libmysqlclient_r.so.15      libmysqlclient.so.15      libmysys.a      mysql_config
libmyisam.a  libmysqlclient_r.a  libmysqlclient_r.so.15.0.0  libmysqlclient.so.15.0.0  libvio.a

/usr/include/mysql/ contains:
chardefs.h  keymaps.h       my_config.h       my_global.h      mysql_com.h      mysql_time.h     readline.h    sql_common.h       tilde.h
decimal.h   m_ctype.h       my_config_i386.h  my_list.h        mysqld_ername.h  mysql_version.h  rlmbutil.h    sql_state.h        typelib.h
errmsg.h    m_string.h      my_dbug.h         my_net.h         mysqld_error.h   my_sys.h         rlprivate.h   sslopt-case.h      xmalloc.h
history.h   my_alloc.h      my_dir.h          my_no_pthread.h  mysql_embed.h    my_xml.h         rlshell.h     sslopt-longopts.h
keycache.h  my_attribute.h  my_getopt.h       my_pthread.h     mysql.h          raid.h           rltypedefs.h  sslopt-vars.h

/usr/share/mysql/ contains:
charsets  english               french     italian      my-innodb-heavy-4G.cnf  mysql_fix_privilege_tables.sql  norwegian     romanian  spanish
czech     errmsg.txt            german     japanese     my-large.cnf            mysql_system_tables_data.sql    norwegian-ny  russian   swedish
danish    estonian              greek      korean       my-medium.cnf           mysql_system_tables.sql         polish        serbian   ukrainian
dutch     fill_help_tables.sql  hungarian  my-huge.cnf  my-small.cnf            mysql_test_data_timezone.sql    portuguese    slovak

Does any of that help?

UPDATE 3

Yes I'm using virtual hosts. Here is my conf file:

Listen 80
NameVirtualHost *:80

<VirtualHost *:80>
        ServerName thedomain.com
        ServerAlias www.thedomain.com
        DocumentRoot /u1/thedomain.com/public
        RailsEnv production
</VirtualHost>

<VirtualHost *:80>
        ServerName subdomain.thedomain.com
        DocumentRoot /u1/subdomain.thedomain.com/public
</VirtualHost>

I'm attempting to setup a basic WordPress install on the subdomain. I'm getting this error still:

Your PHP installation appears to be missing the MySQL extension which is required by WordPress.

SOLVED

I just added –with-mysql (with no path) to the PHP config and reinstalled it and PHP just found what it needed from MySQL on its own apparently. Thanks for the insight everyone.