Issues installing mediawiki

[yaneurabeya]

Hello,
I know this is somewhat unrelated to Gentoo, but I was just wondering in general what the syntax was for the php.ini file since I can't seem to find any proper documentation on how to do mysql.default_socket. Also, does php most of the time run as a separate user or does it have the same environment variables as I do, because it's difficult keeping track of my home ($HOME) variable since my school's sysadmin changes it frequently.
Thanks!