RPM HOWTO (RPM at Idle)
  Donnie Barnes, djb@redhat.com
  v2.0, 8 April 1997

  1.  Introduction

  RPM is the Red Hat Package Manager.  While it does contain Red Hat in
  the name, it is completely intended to be an open packaging system
  available for anyone to use.  It allows users to take source code for
  new software and package it into source and binary form such that
  binaries can be easily installed and tracked and source can be rebuilt
  easily.  It also maintains a database of all packages and their files
  that can be used for verifying packages and querying for information
  about files and/or packages.

  Red Hat Software encourages other distribution vendors to take the
  time to look at RPM and use it for their own distributions.  RPM is
  quite flexible and easy to use, though it provides the base for a very
  extensive system.  It is also completely open and available, though we
  would appreciate bug reports and fixes.   Permission is granted to use
  and distribute RPM royalty free under the GPL.

  More complete documentation is available on RPM in the book by Ed
  Bailey, Maximum RPM.  That book is available for download or purchase
  at www.redhat.com <http://www.redhat.com>.

  2.  Overview

  First, let me state some of the philosophy behind RPM.  One design
  goal was to allow the use of ``pristine'' sources.  With RPP (our
  former packaging system of which none of RPM is derived), our source
  packages were the ``hacked'' sources that we built from.
  Theoretically, one could install a source RPP and then make it with no
  problems.  But the sources were not the original ones, and there was
  no reference as to what changes we had to make to get it to build.
  One had to download the pristine sources separately.  With RPM, you
  have the pristine sources along with a patch that we used to compile
  from.  We see this as a big advantage.  Why?  Several reasons.  For
  one, if a new version of a program comes out, you don't necessarily
  have to start from scratch to get it to compile under RHL.  You can
  look at the patch to see what you might need to do.  All the compile-
  in defaults are easily visible this way.

  RPM is also designed to have powerful querying options.  You can do
  searches through your entire database for packages or just certain
  files.  You can also easily find out what package a file belongs to
  and where it came from.  The RPM files themselves are compressed
  archives, but you can query individual packages easily and quickly
  because of a custom binary header added to the package with everything
  you could possibly need to know contained in uncompressed form.  This
  allows for fast querying.

  Another powerful feature is the ability to verify packages.  If you
  are worried that you deleted an important file for some package, just
  verify it.  You will be notified of any anomalies.  At that point, you
  can reinstall the package if necessary.  Any config files that you had
  are preserved as well.

  We would like to thank the folks from the BOGUS distribution for many
  of their ideas and concepts that are included in RPM.  While RPM was
  completely written by Red Hat Software, its operation is based on code
  written by BOGUS (PM and PMS).

  3.  General Information

  3.1.  Acquiring RPM

  The best way to get RPM is to install Red Hat Linux.  If you don't
  want to do that, you can still get and use RPM.  It can be acquired
  from ftp.redhat.com <ftp://ftp.redhat.com/pub/redhat/code/rpm>.

  3.2.  RPM Requirements

  The main requirement to run RPM is cpio 2.4.2 or greater.  While this
  system is intended for use with Linux, it may very well be portable to
  other Unix systems.  It has, in fact, been compiled on SunOS, Solaris,
  AIX, Irix, AmigaOS, and others.  Be warned, the binary packages
  generated on a different type of Unix system will not be compatible.

  Those are the minimal requirements to install RPMs.  To build RPMs
  from source, you also need everything normally required to build a
  package, like gcc, make, etc.

  4.  Using RPM

  In its simplest form, RPM can be used to install packages:

               rpm -i foobar-1.0-1.i386.rpm

  The next simplest command is to uninstall a package:

               rpm -e foobar

  One of the more complex but highly useful commands allows you to
  install packages via FTP.  If you are connected to the net and want to
  install a new package, all you need to do is specify the file with a
  valid URL, like so:

               rpm -i ftp://ftp.pht.com/pub/linux/redhat/rh-2.0-beta/RPMS/foobar-1.0-1.i386.rpm

  Please note, that RPM will now query and/or install via FTP.

  While these are simple commands, rpm can be used in a multitude of
  ways as seen from the Usage message:

  RPM version 2.3.9
  Copyright (C) 1997 - Red Hat Software
  This may be freely redistributed under the terms of the GNU Public License

  usage: rpm {--help}
         rpm {--version}
         rpm {--initdb}   [--dbpath <dir>]
         rpm {--install -i} [-v] [--hash -h] [--percent] [--force] [--test]
                          [--replacepkgs] [--replacefiles] [--root <dir>]
                          [--excludedocs] [--includedocs] [--noscripts]
                          [--rcfile <file>] [--ignorearch] [--dbpath <dir>]
                          [--prefix <dir>] [--ignoreos] [--nodeps]
                          [--ftpproxy <host>] [--ftpport <port>]
                          file1.rpm ... fileN.rpm
         rpm {--upgrade -U} [-v] [--hash -h] [--percent] [--force] [--test]
                          [--oldpackage] [--root <dir>] [--noscripts]
                          [--excludedocs] [--includedocs] [--rcfile <file>]
                          [--ignorearch]  [--dbpath <dir>] [--prefix <dir>]
                          [--ftpproxy <host>] [--ftpport <port>]
                          [--ignoreos] [--nodeps] file1.rpm ... fileN.rpm
         rpm {--query -q} [-afpg] [-i] [-l] [-s] [-d] [-c] [-v] [-R]
                          [--scripts] [--root <dir>] [--rcfile <file>]
                          [--whatprovides] [--whatrequires] [--requires]
                          [--ftpuseport] [--ftpproxy <host>] [--ftpport <port>]
                          [--provides] [--dump] [--dbpath <dir>] [targets]
         rpm {--verify -V -y} [-afpg] [--root <dir>] [--rcfile <file>]
                          [--dbpath <dir>] [--nodeps] [--nofiles] [--noscripts]
                          [--nomd5] [targets]
         rpm {--setperms} [-afpg] [target]
         rpm {--setugids} [-afpg] [target]
         rpm {--erase -e} [--root <dir>] [--noscripts] [--rcfile <file>]
                          [--dbpath <dir>] [--nodeps] [--allmatches]
                          package1 ... packageN
         rpm {-b|t}[plciba] [-v] [--short-circuit] [--clean] [--rcfile  <file>]
                          [--sign] [--test] [--timecheck <s>] specfile
         rpm {--rebuild} [--rcfile <file>] [-v] source1.rpm ... sourceN.rpm
         rpm {--recompile} [--rcfile <file>] [-v] source1.rpm ... sourceN.rpm
         rpm {--resign} [--rcfile <file>] package1 package2 ... packageN
         rpm {--addsign} [--rcfile <file>] package1 package2 ... packageN
         rpm {--checksig -K} [--nopgp] [--nomd5] [--rcfile <file>]
                             package1 ... packageN
         rpm {--rebuilddb} [--rcfile <file>] [--dbpath <dir>]
         rpm {--querytags}

  You can find more details on what those options do in the RPM man
  page.

  5.  Now what can I really do with RPM?

  RPM is a very useful tool and, as you can see, has several options.
  The best way to make sense of them is to look at some examples.  I
  covered simple install/uninstall above, so here are some more
  examples:

  �  Let's say you delete some files by accident, but you aren't sure
     what you deleted.  If you want to verify your entire system and see
     what might be missing, you would do:

       rpm -Va

  �  Let's say you run across a file that you don't recognize.  To find
     out which package owns it, you would do:

       rpm -qf /usr/X11R6/bin/xjewel

  The output would be:

       xjewel-1.6-1

  �  You find a new koules RPM, but you don't know what it is.  To find
     out some information on it, do:

       rpm -qpi koules-1.2-2.i386.rpm

  The output would be:

       Name        : koules                      Distribution: Red Hat Linux Colgate
       Version     : 1.2                               Vendor: Red Hat Software
       Release     : 2                             Build Date: Mon Sep 02 11:59:12 1996
       Install date: (none)                        Build Host: porky.redhat.com
       Group       : Games                         Source RPM: koules-1.2-2.src.rpm
       Size        : 614939
       Summary     : SVGAlib action game with multiplayer, network, and sound support
       Description :
       This arcade-style game is novel in conception and excellent in execution.
       No shooting, no blood, no guts, no gore.  The play is simple, but you
       still must develop skill to play.  This version uses SVGAlib to
       run on a graphics console.

  �  Now you want to see what files the koules RPM installs.  You would
     do:

       rpm -qpl koules-1.2-2.i386.rpm

  The output is:

  /usr/doc/koules
  /usr/doc/koules/ANNOUNCE
  /usr/doc/koules/BUGS
  /usr/doc/koules/COMPILE.OS2
  /usr/doc/koules/COPYING
  /usr/doc/koules/Card
  /usr/doc/koules/ChangeLog
  /usr/doc/koules/INSTALLATION
  /usr/doc/koules/Icon.xpm
  /usr/doc/koules/Icon2.xpm
  /usr/doc/koules/Koules.FAQ
  /usr/doc/koules/Koules.xpm
  /usr/doc/koules/README
  /usr/doc/koules/TODO
  /usr/games/koules
  /usr/games/koules.svga
  /usr/games/koules.tcl
  /usr/man/man6/koules.svga.6

  These are just several examples.  More creative ones can be thought of
  really easy once you are familiar with RPM.

  6.  Building RPMs

  Building RPMs is fairly easy to do, especially if you can get the
  software you are trying to package to build on its own.

  The basic procedure to build an RPM is as follows:

  �  Make sure your /etc/rpmrc is setup for your system.

  �  Get the source code you are building the RPM for to build on your
     system.

  �  Make a patch of any changes you had to make to the sources to get
     them to build properly.

  �  Make a spec file for the package.

  �  Make sure everything is in its proper place.

  �  Build the package using RPM.

  Under normal operation, RPM builds both binary and source packages.

  6.1.  The rpmrc File

  Right now, the only configuration of RPM is available via the
  /etc/rpmrc file.  An example one looks like:

  require_vendor: 1
  distribution: I roll my own!
  require_distribution: 1
  topdir: /usr/src/me
  vendor: Mickiesoft
  packager:  Mickeysoft Packaging Account <packages@mickiesoft.com>

  optflags: i386 -O2 -m486 -fno-strength-reduce
  optflags: alpha -O2
  optflags: sparc -O2

  signature: pgp
  pgp_name: Mickeysoft Packaging Account
  pgp_path: /home/packages/.pgp

  tmppath: /usr/tmp

  The require_vendor line causes RPM to require that it find a vendor
  line.  This can come from the /etc/rpmrc or from the header of the
  spec file itself.  To turn this off, change the number to 0.  The same
  holds true for the require_distribution and require_group lines.

  The next line is the distribution line.  You can define that here or
  later in the header of the spec file.  When building for a particular
  distribution, it's a good idea to make sure this line is correct, even
  though it is not required.  The vendor  line works much the same way,
  but can be anything (ie. Joe's Software and Rock Music Emporium).

  RPM also now has support for building packages on multiple
  architectures.  The rpmrc file can hold an ``optflags'' variable for
  building things that require architecture specific flags when
  building.  See later sections for how to use this variable.

  In addition to the above macros, there are several more.  You can use:

       rpm --showrc

  to find out how your tags are set and what all the available flags
  are.

  6.2.  The Spec File

  We'll begin with discussion of the spec file.  Spec files are required
  to build a package.  The spec file is a description of the software
  along with instructions on how to build it and a file list for all the
  binaries that get installed.

  You'll want to name your spec file according to a standard convention.
  It should be the package name-dash-version number-dash-release number-
  dot-spec.

  Here is a small spec file (vim-3.0-1.spec):

  Summary: ejects ejectable media and controls auto ejection
  Name: eject
  Version: 1.4
  Release: 3
  Copyright: GPL
  Group: Utilities/System
  Source: sunsite.unc.edu:/pub/Linux/utils/disk-management/eject-1.4.tar.gz
  Patch: eject-1.4-make.patch
  Patch1: eject-1.4-jaz.patch
  %description
  This program allows the user to eject media that is autoejecting like
  CD-ROMs, Jaz and Zip drives, and floppy drives on SPARC machines.

  %prep
  %setup
  %patch -p1
  %patch1 -p1

  %build
  make RPM_OPT_FLAGS="$RPM_OPT_FLAGS"

  %install
  install -s -m 755 -o 0 -g 0 eject /usr/bin/eject
  install -m 644 -o 0 -g 0 eject.1 /usr/man/man1

  %files
  %doc README COPYING ChangeLog

  /usr/bin/eject
  /usr/man/man1/eject.1

  6.3.  The Header

  The header has some standard fields in it that you need to fill in.
  There are a few caveats as well.  The fields must be filled in as
  follows:

  �  Summary: This is a one line description of the package.

  �  Name: This must be the name string from the rpm filename you plan
     to use.

  �  Version: This must be the version string from the rpm filename you
     plan to use.

  �  Release: This is the release number for a package of the same
     version (ie. if we make a package and find it to be slightly broken
     and need to make it again, the next package would be release number
     2).

  �  Icon: This is the name of the icon file for use by other high level
     installation tools (like Red Hat's ``glint'').  It must be a gif
     and resides in the SOURCES directory.

  �  Source: This line points at the HOME location of the pristine
     source file.  It is used if you ever want to get the source again
     or check for newer versions.  Caveat:  The filename in this line
     MUST match the filename you have on your own system (ie. don't
     download the source file and change its name).  You can also
     specify more than one source file using lines like:

  Source0: blah-0.tar.gz
  Source1: blah-1.tar.gz
  Source2: fooblah.tar.gz

  These files would go in the SOURCES directory. (The directory struc�
  ture is discussed in a later section, "The Source Directory Tree".)

  �  Patch: This is the place you can find the patch if you need to
     download it again.  Caveat:  The filename here must match the one
     you use when you make YOUR patch.  You may also want to note that
     you can have multiple patch files much as you can have multiple
     sources.  ] You would have something like:

       Patch0: blah-0.patch
       Patch1: blah-1.patch
       Patch2: fooblah.patch

  These files would go in the SOURCES directory.

  �  Copyright: This line tells how a package is copyrighted.  You
     should use something like GPL, BSD, MIT, public domain,
     distributable, or commercial.

  �  BuildRoot: This line allows you to specify a directory as the
     ``root'' for building and installing the new package.  You can use
     this to help test your package before having it installed on your
     machine.

  �  Group: This line is used to tell high level installation programs
     (such as Red Hat's ``glint'') where to place this particular
     program in its hierarchical structure.  The group tree currently
     looks something like this:

  Applications
      Communications
      Editors
          Emacs
      Engineering
      Spreadsheets
      Databases
      Graphics
      Networking
      Mail
      Math
      News
      Publishing
          TeX
  Base
      Kernel
  Utilities
      Archiving
      Console
      File
      System
      Terminal
      Text
  Daemons
  Documentation
  X11
      XFree86
          Servers
      Applications
          Graphics
          Networking
      Games
          Strategy
          Video
      Amusements
      Utilities
      Libraries
      Window Managers
  Libraries
  Networking
      Admin
      Daemons
      News
      Utilities
  Development
      Debuggers
      Libraries
          Libc
      Languages
          Fortran
          Tcl
      Building
      Version Control
      Tools
  Shells
  Games

  �  %description  It's not really a header item, but should be
     described with the rest of the header.  You need one description
     tag per package and/or subpackage.  This is a multi-line field that
     should be used to give a comprehensive description of the package.

  6.4.  Prep

  This is the second section in the spec file.  It is used to get the
  sources ready to build.  Here you need to do anything necessary to get
  the sources patched and setup like they need to be setup to do a make.

  One thing to note:  Each of these sections is really just a place to
  execute shell scripts.  You could simply make an sh script and put it
  after the %prep tag to unpack and patch your sources.  We have made
  macros to aid in this, however.

  The first of these macros is the %setup macro.  In its simplest form
  (no command line options), it simply unpacks the sources and cd's into
  the source directory.  It also takes the following options:

  �  -n name will set the name of the build directory to the listed
     name.  The default is $NAME-$VERSION.  Other possibilities include
     $NAME, ${NAME}${VERSION}, or whatever the main tar file uses.
     (Please note that these ``$'' variables are not real variables
     available within the spec file.  They are really just used here in
     place of a sample name.  You need to use the real name and version
     in your package, not a variable.)

  �  -c will create and cd to the named directory before doing the
     untar.

  �  -b # will untar Source# before cd'ing into the directory (and this
     makes no sense with -c so don't do it).  This is only useful with
     multiple source files.

  �  -a # will untar Source# after cd'ing into the directory.

  �  -T This option overrides the default action of untarring the Source
     and requires a -b 0 or -a 0 to get the main source file untarred.
     You need this when there are secondary sources.

  �  -D Do not delete the directory before unpacking.  This is only
     useful where you have more than one setup macro.  It should only be
     used in setup macros after the first one (but never in the first
     one).

  The next of the available macros is the %patch macro.  This macro
  helps automate the process of applying patches to the sources.  It
  takes several options, listed below:

  �  # will apply Patch# as the patch file.

  �  -p # specifies the number of directories to strip for the patch(1)
     command.

  �  -P The default action is to apply Patch (or Patch0).  This flag
     inhibits the default action and will require a 0 to get the main
     source file untarred.  This option is useful in a second (or later)
     %patch macro that required a different number than the first macro.

  �  You can also do %patch# instead of doing the real command: %patch #
     -P

  That should be all the macros you need.  After you have those right,
  you can also do any other setup you need to do via sh type scripting.
  Anything you include up until the %build macro (discussed in the next
  section) is executed via sh.  Look at the example above for the types
  of things you might want to do here.

  6.5.  Build

  There aren't really any macros for this section.  You should just put
  any commands here that you would need to use to build the software
  once you had untarred the source, patched it, and cd'ed into the
  directory.  This is just another set of commands passed to sh, so any
  legal sh commands can go here (including comments).  Your current
  working directory is reset in each of these sections to the toplevel
  of the source directory, so keep that in mind.  You can cd into
  subdirectories if necessary.

  6.6.  Install

  There aren't really any macros here, either.  You basically just want
  to put whatever commands here that are necessary to install.  If you
  have make install available to you in the package you are building,
  put that here.  If not, you can either patch the makefile for a make
  install and just do a make install here, or you can hand install them
  here with sh commands.  You can consider your current directory to be
  the toplevel of the source directory.

  6.7.  Optional pre and post Install/Uninstall Scripts

  You can put scripts in that get run before and after the installation
  and uninstallation of binary packages.  A main reason for this is to
  do things like run ldconfig after installing or removing packages that
  contain shared libraries.  The macros for each of the scripts is as
  follows:

  �  %pre is the macro to do pre-install scripts.

  �  %post is the macro to do post-install scripts.

  �  %preun is the macro to do pre-uninstall scripts.

  �  %postun is the macro to do post-uninstall scripts.

  The contents of these sections should just be any sh style script,
  though you do not need the #!/bin/sh.

  6.8.  Files

  This is the section where you must list the files for the binary
  package.  RPM has no way to know what binaries get installed as a
  result of make install.  There is NO way to do this.  Some have
  suggested doing a find before and after the package install.  With a
  multiuser system, this is unacceptable as other files may be created
  during a package building process that have nothing to do with the
  package itself.

  There are some macros available to do some special things as well.
  They are listed and described here:

  �  %doc is used to mark documentation in the source package that you
     want installed in a binary install.  The documents will be
     installed in /usr/doc/$NAME-$VERSION-$RELEASE.  You can list
     multiple documents on the command line with this macro, or you can
     list them all separately using a macro for each of them.

  �  %config is used to mark configuration files in a package.  This
     includes files like sendmail.cf, passwd, etc.  If you later
     uninstall a package containing config files, any unchanged files
     will be removed and any changed files will get moved to their old
     name with a .rpmsave appended to the filename.  You can list
     multiple files with this macro as well.

  �  %dir marks a single directory in a file list to be included as
     being owned by a package.  By default, if you list a directory name
     WITHOUT a %dir macro, EVERYTHING in that directory is included in
     the file list and later installed as part of that package.

  �  %files -f <filename> will allow you to list your files in some
     arbitrary file within the build directory of the sources.  This is
     nice in cases where you have a package that can build it's own
     filelist.  You then just include that filelist here and you don't
     have to specifically list the files.

  The biggest caveat in the file list is listing directories.  If you
  list /usr/bin by accident, your binary package will contain every file
  in /usr/bin on your system.

  6.9.  Building It

  6.9.1.  The Source Directory Tree

  The first thing you need is a properly configured build tree.  This is
  configurable using the /etc/rpmrc file.  Most people will just use
  /usr/src.

  You may need to create the following directories to make a build tree:

  �  BUILD is the directory where all building occurs by RPM.  You don't
     have to do your test building anywhere in particular, but this is
     where RPM will do it's building.

  �  SOURCES is the directory where you should put your original source
     tar files and your patches.  This is where RPM will look by
     default.

  �  SPECS is the directory where all spec files should go.

  �  RPMS is where RPM will put all binary RPMs when built.

  �  SRPMS is where all source RPMs will be put.

  6.9.2.  Test Building

  The first thing you'll probably want to to is get the source to build
  cleanly without using RPM.  To do this, unpack the sources, and change
  the directory name to $NAME.orig.  Then unpack the source again.  Use
  this source to build from.  Go into the source directory and follow
  the instructions to build it.  If you have to edit things, you'll need
  a patch.  Once you get it to build, clean the source directory.  Make
  sure and remove any files that get made from a configure script.  Then
  cd back out of the source directory to its parent.  Then you'll do
  something like:

               diff -uNr dirname.orig dirname > ../SOURCES/dirname-linux.patch

  This will create a patch for you that you can use in your spec file.
  Note that the ``linux'' that you see in the patch name is just an
  identifier.  You might want to use something more descriptive like
  ``config'' or ``bugs'' to describe why you had to make a patch.  It's
  also a good idea to look at the patch file you are creating before
  using it to make sure no binaries were included by accident.

  6.9.3.  Generating the File List

  Now that you have source that will build and you know how to do it,
  build it and install it.  Look at the output of the install sequence
  and build your file list from that to use in the spec file.  We
  usually build the spec file in parallel with all of these steps.  You
  can create the initial one and fill in the easy parts, and then fill
  in the other steps as you go.

  6.9.4.  Building the Package with RPM

  Once you have a spec file, you are ready to try and build your
  package.  The most useful way to do it is with a command like the
  following:

               rpm -ba foobar-1.0.spec

  There are other options useful with the -b switch as well:

  �  p means just run the prep section of the specfile.

  �  l is a list check that does some checks on %files.

  �  c do a prep and compile.  This is useful when you are unsure of
     whether your source will build at all.  It seems useless because
     you might want to just keep playing with the source itself until it
     builds and then start using RPM, but once you become accustomed to
     using RPM you will find instances when you will use it.

  �  i do a prep, compile, and install.

  �  b prep, compile, install, and build a binary package only.

  �  a build it all (both source and binary packages).

     There are several modifiers to the -b switch.  They are as follows:

  �  --short-circuit will skip straight to a specified stage (can only
     be used with c and i).

  �  --clean removes the build tree when done.

  �  --keep-temps will keep all the temp files and scripts that were
     made in /tmp.  You can actually see what files were created in /tmp
     using the -v option.

  �  --test does not execute any real stages, but does keep-temp.

  6.10.  Testing It

  Once you have a source and binary rpm for your package, you need to
  test it.  The easiest and best way is to use a totally different
  machine from the one you are building on to test.  After all, you've
  just done a lot of make install's on your own machine, so it should be
  installed fairly well.

  You can do an rpm -u packagename on the package to test, but that can
  be deceiving because in building the package, you did a make install.
  If you left something out of your file list, it will not get
  uninstalled.  You'll then reinstall the binary package and your system
  will be complete again, but your rpm still isn't.  Make sure and keep
  in mind that just because you do a rpm -ba package, most people
  installing your package will just be doing the rpm -i package.  Make
  sure you don't do anything in the build or install sections that will
  need to be done when the binaries are installed by themselves.

  6.11.  What to do with your new RPMs

  Once you've made your own RPM of something (assuming its something
  that hasn't already been RPM'ed), you can contribute your work to
  others (also assuming you RPM'ed something freely distributable).  To
  do so, you'll want to upload it to ftp.redhat.com
  <ftp://ftp.redhat.com>.

  6.12.  What Now?

  Please see the above sections on Testing and What to do with new RPMs.
  We want all the RPMs available we can get, and we want them to be good
  RPMs.  Please take the time to test them well, and then take the time
  to upload them for everyone's benefit.  Also, please make sure you are
  only uploading freely available software.  Commercial software and
  shareware should not be uploaded unless they have a copyright
  expressly stating that this is allowed.  This includes Netscape
  software, ssh, pgp, etc.

  7.  Multi-architectural RPM Building

  RPM can now be used to build packages for the Intel i386, the Digital
  Alpha running Linux, and the Sparc.  It has been reported to work on
  SGI's and HP workstations as well.  There are several features that
  make building packages on all platforms easy.  The first of these is
  the ``optflags'' directive in the /etc/rpmrc.  It can be used to set
  flags used when building software to architecture specific values.
  Another feature is the ``arch'' macros in the spec file.  They can be
  used to do different things depending on the architecture you are
  building on.  Another feature is the ``Exclude'' directive in the
  header.

  7.1.  Sample spec File

  The following is part of the spec file for the ``fileutils'' package.
  It is setup to build on both the Alpha and the Intel.

  Summary: GNU File Utilities
  Name: fileutils
  Version: 3.16
  Release: 1
  Copyright: GPL
  Group: Utilities/File
  Source0: prep.ai.mit.edu:/pub/gnu/fileutils-3.16.tar.gz
  Source1: DIR_COLORS
  Patch: fileutils-3.16-mktime.patch

  %description
  These are the GNU file management utilities.  It includes programs
  to copy, move, list, etc, files.

  The ls program in this package now incorporates color ls!

  %prep
  %setup

  %ifarch alpha
  %patch -p1
  autoconf
  %endif
  %build
  configure --prefix=/usr --exec-prefix=/
  make CFLAGS="$RPM_OPT_FLAGS" LDFLAGS=-s

  %install
  rm -f /usr/info/fileutils*
  make install
  gzip -9nf /usr/info/fileutils*

  7.2.  Optflags

  In this example, you see how the ``optflags'' directive is used from
  the /etc/rpmrc.  Depending on which architecture you are building on,
  the proper value is given to RPM_OPT_FLAGS.  You must patch the
  Makefile for your package to use this variable in place of the normal
  directives you might use (like -m486 and -O2).  You can get a better
  feel for what needs to be done by installing this source package and
  then unpacking the source and examine the Makefile.  Then look at the
  patch for the Makefile and see what changes must be made.

  7.3.  Macros

  The %ifarch macro is very important to all of this.  Most times you
  will need to make a patch or two that is specific to one architecture
  only.  In this case, RPM will allow you to apply that patch to just
  one architecture only.

  In the above example, fileutils has a patch for 64 bit machines.
  Obviously, this should only be applied on the Alpha at the moment.
  So, we add an %ifarch macro around the 64 bit patch like so:

       %ifarch axp
       %patch1 -p1
       %endif

  This will insure that the patch is not applied on any architecture
  except the alpha.

  7.4.  Excluding Architectures from Packages

  So that you can maintain source RPMs in one directory for all
  platforms, we have implemented the ability to ``exclude'' packages
  from being built on certain architectures.  This is so you can still
  do things like

       rpm --rebuild /usr/src/SRPMS/*.rpm

  and have the right packages build.  If you haven't yet ported an
  application to a certain platform, all you have to do is add a line
  like:

       ExcludeArch: axp

  to the header of the spec file of the source package.  Then rebuild
  the package on the platform that it does build on.  You'll then have a
  source package that builds on an Intel and can easily be skipped on an
  Alpha.

  7.5.  Finishing Up

  Using RPM to make multi-architectural packages is usually easier to do
  than getting the package itself to build both places.  As more of the
  hard packages get built this is getting much easier, however.  As
  always, the best help when you get stuck building an RPM is to look a
  similar source package.

  8.  Copyright Notice

  This document and its contents are copyright protected.
  Redistribution of this document is permitted as long as the content
  remains completely intact and unchanged.  In other words, you may
  reformat and reprint or redistribute only.