Page that checks if a user exists on a remote system

I have two servers: ServerA and ServerB. One server serves web pages, the other serves mail. I am making a web page on ServerA that will access ServerB to find out if a users exists and if not then add that user to ServerB with information collected from the web page on ServerA. I have this in a php file: $idResults = ssh admin@domain.com id bigbob 2>&1; echo "id: (".$idResults.")\r\n"."\r\n"; if (ereg("no such user", $idResults)) { echo 'username is available!'; } When I access the page I get: Could not create directory '/nonexistent/.ssh'. Host key verification failed. This, of course, is because the script is being run as "www" who has no place to put ssl keys. Could this be solved by having "www" "su" to a user who has remote access privileges? Something like this: $idResults = su admin | ssh admin@domain.com id bigbob 2>&1; echo "id: (".$idResults.")\r\n"."\r\n"; if (ereg("no such user", $idResults)) { echo 'username is available!'; // function addUserToServerB(vars); } Anyone else doing or done something like this? Thanks, -- Jonathan Duncan http://www.nacnud.com