Do you have any PHP functions disabled for security?

The following php functions are disabled on servers, to provide better security;

ini_alter,system,passthru,shell_exec,leak,listen,c hgrp,apache_setenv,define_syslog_variables,openlog ,syslog,ftp_exec

This will provide our users with better security against poorly coded php scripts, as usage of this functions should not be needed/useful in php scripts. This has been tested thoroughly, before implemention