Installing Multi-Byte PHP Functions

I received this error today:

Fatal error: Call to undefined function mb_strlen()

And it would look the same, no matter what multi-byte PHP function I might be using: mb_strpos(), mb_substr(), etc. And it is beginning to be important to have this extensions installed if you are working with international, multi-byte character sets like UTF-8.

The fix is super easy. All you need to do is install the PHP multi-byte extension with yum (if you're on CentOS or RHEL). Do the following from the command line:

yum install php-mbstring
service httpd restart

That installs the extension and restarts Apache. Then you're good to go!

Installing Memcached on CentOS

I have a web server running CentOS and wanted to get some good caching going for PHP use. This is how I installed memcached, from the command line:

• Install memcached
• yum install memcached
• Install Pecl (if you don't yet have it, installing pear installs pecl)
• yum install php-pear
• Install Pecl's Memcached package (for PHP)
• Install dependencies, as needed
• yum install php-devel
• yum install gcc
• yum install zlib-devel
• pecl install memcache
• Use a text editor to add "extension=memcache.so" to php.ini (may be in the /etc folder)
• Restart the service
• service memcached start 
• service httpd restart

And when you want some raw stats, you can get them via telnet:

• telnet localhost 11211

And type "stats" to see hits, misses and more!

Here are some examples of memcached use in PHP.