userv (pronounced you-serve) is a program which, according to the
a Unix system facility to allow one program to invoke another when
only limited trust exists between them.
It is a tool for system administrators, who often find themselves with
a program running as one user which needs to be able to do certain
things as another user. For example, my machine's news system needs to
scan my users' newsrcs to ensure that the right newsgroups are
fetched. Before userv that part of the news system had to run as root,
and clumsily use `su'.
It is also a component for application authors. For example, imagine a
version of `cron' which didn't need to run as root, so that a security
bug in cron would just mean that bad people could get cron jobs to run
at the wrong times, rather than everyone on the system being able to
break in completely. Imagine being able to do sophisticated mail
filtering at delivery time without the mail transfer or delivery
agents needing to be root.
If you are subscribed to userv-discuss please send bug reports there;
otherwise mail them to email@example.com.
I have set up mailinglists userv-announce and userv-discuss. The
announcements list is moderated and will contain only announcements of
important bugs, new versions, &c. The bug reports address mentioned
above is also a mailing list; feel free to subscribe to it.
There are archives and subscription web pages, or you can subscribe
by sending mail containing the word `subscribe' to
Available for download from chiark.greenend.org.uk are:
* The current version as a gzipped tarfile.
* Debian GNU/Linux source and binary packages are available via
* All versions distributed so far are also available via
* The HTML specification, including notes on how and why to
use it. The specification is also available as a gzipped
PostScript file. (The Debiandoc-SGML source for the spec is in the
* The overview diagram as PostScript, or in the original xfig
* The changelog as a plain text file.
* The slides for a talk I gave at the 1998 UKUUG Linux Event in
Manchester and earlier at the 1998 Linux Kongress in Cologne.
* A mirror of my CVS repository is available via rsync from
rsync.chiark.greenend.org.uk::ftp/users/ian/cvs-pub/userv (use FTP
first to find your way around), or via cvsweb.
userv is also available from the GNU Project FTP servers and their
Copyright and licensing
userv is Copyright 1996-1999 Ian Jackson.
userv is free software; you can redistribute it and/or modify it under
the terms of the GNU General Public License as published by the Free
Software Foundation; either version 2 of the License, or (at your
option) any later version.
This program and documentation is distributed in the hope that it will
be useful, but without any warranty; without even the implied warranty
of merchantability or fitness for a particular purpose. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with userv, or one should be available above; if not, write to
the Free Software Foundation, 59 Temple Place - Suite 330, Boston,
MA 02111-1307, USA, or email firstname.lastname@example.org.
Ian Jackson / email@example.com; more
free software by me.
GNU home page; chiark home page; site or mirror home page
This web page is Copyright (C)1996-1999 Ian Jackson. See the
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