how would I add 100 virtual users to pure-ftpd?

To: fedora-list@xxxxxxxxxx
Subject: how would I add 100 virtual users to pure-ftpd?
From: James Pang <jamesqingdao@xxxxxxxxx>
Date: Tue, 22 Nov 2005 12:24:58 +0800
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What does "pure-pw useradd <login> [-f <passwd file>] -u <uid> [-g <gid>]"
passwd file means?