--
-- Copyright (c) 2005, Markus W. Weissmann <mww@opendarwin.org>
--
-- Redistribution and use in source and binary forms, with or without
-- modification, are permitted provided that the following conditions
-- are met:
-- 1. Redistributions of source code must retain the above copyright
--    notice, this list of conditions and the following disclaimer.
-- 2. Redistributions in binary form must reproduce the above copyright
--    notice, this list of conditions and the following disclaimer in the
--    documentation and/or other materials provided with the distribution.
-- 3. Neither the name of OpenDarwin nor the names of its contributors
--    may be used to endorse or promote products derived from this software
--    without specific prior written permission.
--
-- THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
-- ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
-- TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
-- PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDERS OR
-- CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
-- EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
-- PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
-- OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
-- WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
-- OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
-- ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
--

usage: xpkg [OPTION]... [TARGETS]

Examples:
  xpkg -i rsync-2.6.2-3.xpkg   # installs the contents of the file
  xpkg --query-name sqlite3    # prints info about the installed package
  xpkg -qf \\*.h                # prints all packages owning a header file
  xpkg -v -l                   # lists all installed packages verbosively

Main operation mode:
  -i, --install                 installs package from given file
  -l, --list                    lists the installed packages
  -r, --register                registers a package without extracting it
  -qn, --query-name             prints information about package by name
  -qf, --query-file             prints information about package owning file
  -c, --createdb                initializes the database
  -e, --erase                   uninstalls package by packagename
  -u, --upgrade                 upgrades package from given package file

Informative output:
  -d, --debug                   enable debug mode
  -h, --help                    print this help, then exit
  -V, --version                 print xpkg version number, then exit
  -v, --verbose                 enable verbose mode

Environment variables:
  XPKG_REGFILE                  sets the path to the xpkg registry database
  XPKG_PKGROOT                  sets the root directory to install to
  XPKG_DEBUG                    if set, xpkg will print debug info (same as -d)
  XPKG_VERBOSE                  if set, xpkg will be verbose (same as -v)
