I tested on two servers, one is the cpanel of the host, a manually compiled environment. cpanel user directory / home / tttttco / public_html, and the apache configuration file is written in this form below:
<IfModule Concurrent_php.c>
php4_admin_value open_basedir "/ home / tttttco: / usr / lib / php: / usr/php4/lib/php: / usr / local / lib / php: / usr/local/php4/lib/php: / tmp"
php5_admin_value open_basedir "/ home / tttttco: / usr / lib / php: / usr / local / lib / php: / tmp"
</ IfModule>
<IfModule !concurrent_php.c>
<IfModule Mod_php4.c>
php_admin_value open_basedir "/ home / tttttco: / usr / lib / php: / usr/php4/lib/php: / usr / local / lib / php: / usr/local/php4/lib/php: / tmp"
</ IfModule>
<IfModule Mod_php5.c>
php_admin_value open_basedir "/ home / tttttco: / usr / lib / php: / usr / local / lib / php: / tmp"
</ IfModule>
<IfModule Sapi_apache2.c>
php_admin_value open_basedir "/ home / tttttco: / usr / lib / php: / usr/php4/lib/php: / usr / local / lib / php: / usr/local/php4/lib/php: / tmp"
</ IfModule>


I manually compiled the environment is as follows:
php_admin_value open_basedir / home / tttttco / public_html

When tested with webshell that cpanel host, the user can not access other users directories, but also be able to access, such as / usr / etc directory and so on. I manually compiled the mainframe environment, users have been locked in their own directory, the directory can not access any of the other. I would like to cpanel host, apache is also set, the user can only access its own directory, an absolute lock-up.