Which Samba command can be used to test user credentials?

The command that can be used to test user credentials is smbclient. This is a versatile tool in the Samba suite that allows users to connect to SMB/CIFS shares. A key feature of smbclient is its ability to authenticate users against a Samba or Windows server. You can use this command to attempt a connection to a share while providing username and password credentials. If the connection is successful, it confirms that the provided credentials are valid.

In practical scenarios, you would run smbclient with the appropriate options, typically specifying the share path and the credentials to check access. This functionality makes smbclient particularly useful for troubleshooting and verifying user permission issues when accessing network shares.

While the other commands in the list have their own purposes, they do not serve to test user credentials in the same way. For instance, smbstatus provides info on current Samba connections and processes, testparm checks the Samba configuration file for errors, and smbtree displays the Samba shares available on the local network. None of these tools are designed for directly testing user credentials.