Specify mount point for Samba share
The open smb:// command is just automating what you're doing manually in Linux

Start by creating the mount point

sudo mkdir /Volumes/foobar


Then mount the share

sudo mount -t smbfs //user@hostname/path/to/share /Volumes/foobar


or 

sudo mount_smbfs //user@hostname/path/to/share /Volumes/foobar