How to detect the user has logged in a domain or local host in the linux shell script?

In the default, the linux doesn't support the domain. But the user can join a domain by applictions, such as: Likewise, Winbind, and so on. For my project, my customers are all enterprise members. For the security problem, most customers' linux host will be joined a domain. Unfortunately, the customer can log in the local host even the linux host has been joined a domain. Such as: (1) The are two accounts in a linux host: a domain account: dev.com\john(the domain is developer.com) a local account: tom (2) The customer can log in with the domain account(dev.com\john) or local account(tom) freely. My task is that write a shell script that will be executed when the user log in. In the shell script, I need to check the user log in with a domain account or a local account. If the user log in with the domain name, I need to get the domain name ; otherwise, I need to get the host name. Then report the domain(or host) name and user name to the remote monitor server. I have tried the following code: hostName=$(hostname) hostFQDN=$(hostname -f) if [ "$hostName" = "$hostFQDN" ]; then # The user didn't log in a domain. hostInfo="$hostName" else # The user logged in a domain. hostInfo=$(hostname -d) fi In the above, I check the host FQDN is equal with the host name or not. If yes, I will believe the customer log in with the domain account; else, local account. Unfortunately, it doesn't work always. The reason is that the host FQDN will not equal with host name always if the linux host is joined a domain, even the customer log in with a local account. Such as: (1) The linux host is joined the domain "dev.com"; (2) The host fqdn will be "yw-host.dev.com" always("yw-host" is the host name), whether the customer log in with domain account or not. Anybody can give a solution please? As my customer can join the domain with multiple domain applications(such as: likewise, winbin, and so on), it is better the solution will not depend on a special domain application. Thanks a lot.