freebsd-nq/share/doc/handbook/porting.sgml

<!-- $Id: porting.sgml,v 1.7 1995/10/07 04:31:35 jfieber Exp $ -->
<!-- The FreeBSD Documentation Project -->

<sect><heading>Porting applications<label id="porting"></heading>

<p><em>Contributed by &a.jkh;, &a.gpalmer; and
      &a.asami;.<newline>19 August 1995.</em>

	Here are the guidelines one should follow in
	creating a new port for FreeBSD 2.x .  This documentation will
	change as this process is progressively refined, so watch
	this space for details.  The <tt>&dollar;{..}</tt>
	variable names you see in this document all refer to
	various user-overridable defaults used (and documented)
	by <tt>/usr/share/mk/bsd.port.mk</tt>.  Please refer to
	that file for more details.

    <sect1>
      <heading>Before Starting the Port</heading>

      <p>Note: Only a fraction of the overridable variables are
	mentioned in this document. Most (if not all) are documented
	at the start of the <tt>bsd.port.mk</tt> file which can be
	found in <tt>/usr/share/mk</tt>. This file uses a non-standard tab
	setting. <tt>Emacs</tt> should recognize the setting on
	loading the file. <tt>vi</tt> or <tt>ex</tt> can be set to
	using the correct value by typing `<tt>:set tabstop=4</tt>'
	once the file has been loaded.

      <p>You may come across code that needs modifications or
	conditional compilation based upon what version of UNIX it's
	running under.  If you need to make such changes to the code
	for conditional compilation, make sure you make the changes as
	general as possible so that we can back-port code to FreeBSD
	1.x systems and cross-port to other BSD systems such as 4.4BSD
	from CSRG, BSD/386, 386BSD and NetBSD.

      <p>The preferred way to tell 4.3BSD/Reno and newer versions of
	the BSD code apart is by using the `<tt>BSD</tt>' macro
	defined in <tt>&lt;sys/param.h&gt;</tt>.  Hopefully that file
	is already included; if not, add the code:

<tscreen><verb>
#ifdef _HAVE_PARAM_H
#include <sys/param.h>
#endif
</verb></tscreen>

	to the proper place in the <tt>.c</tt> file and add
	<tt>-D_HAVE_PARAM_H</tt> to the <tt>CFLAGS</tt> in the
	Makefile.

	Then, you may use:

<tscreen><verb>
#if (defined(BSD) && (BSD >= 199103))
</verb></tscreen>

	to detect if the code is being compiled on a 4.3 Net2 code
	base or newer (e.g. FreeBSD 1.x, 4.3/Reno, NetBSD 0.9, 386BSD,
	BSD/386 1.1 and below).

	Use:

<tscreen><verb>
#if (defined(BSD) && (BSD >= 199306))
</verb></tscreen>

	to detect if the code is being compiled on a 4.4 code base or
	newer (e.g. FreeBSD 2.x, 4.4, NetBSD 1.0, BSD/386 2.0 or
	above).

      <p>Use sparingly:

      <itemize>
	<item><tt>__FreeBSD__</tt> is defined in all versions of
	  FreeBSD.  Use it if the change you are making ONLY affects
	  FreeBSD.  Porting gotchas like the use of
	  <tt>sys_errlist[]</tt> vs <tt>strerror()</tt> are
	  Berkeleyisms, not FreeBSD changes.

	<item>In FreeBSD 2.x, <tt>__FreeBSD__</tt> is defined to be
	  <tt>2</tt>.  In earlier versions, it's <tt>1</tt>.

	<item>If you need to tell the difference between a FreeBSD 1.x
	  system and a FreeBSD 2.x system, usually the right answer is
	  to use the <tt>BSD</tt> macros described above.  If there
	  actually is a FreeBSD specific change (such as special
	  shared library options when using `<tt>ld</tt>') then it's
	  OK to use <tt>__FreeBSD__</tt> and `<tt>#if __FreeBSD_ &gt;
	  1</tt>' to detect a FreeBSD 2.x system.

      </itemize>

      <p>In the dozens of ports that have been done, there have
	only been one or two cases where <tt>__FreeBSD__</tt>
	should have been used.  Just because an earlier port
	screwed up and used it in the wrong place doesn't mean
	you should do so too.

    <sect1>
      <heading>Quick Porting</heading>

      <p>This section tells you how to do a quick port.  In many
	cases, it is not enough, but we'll see.

      <p>First, get the original tarball and put it into
	<tt>&dollar;{DISTDIR}</tt>, which defaults to
	<tt>/usr/ports/distfiles</tt>.

      <p>Note: The following assumes that the software compiled
	out-of-the-box, i.e., there was absolutely no change required
	for the port to work on your FreeBSD box.  If you needed to
	change something, you'll have to refer to the next section
	too.

      <sect2>
	<heading>Writing the Makefile</heading>

	<p>The minimal <tt>Makefile</tt> would look something like this:

<tscreen><verb>
 # New ports collection makefile for:	oneko
 # Version required:	1.1b
 # Date created:		5 December 1994
 # Whom:			asami
 #
 # $Id: porting.sgml,v 1.7 1995/10/07 04:31:35 jfieber Exp $
 #
 
 DISTNAME=	oneko-1.1b
 CATEGORIES+=	games
 MASTER_SITES=	ftp://ftp.cs.columbia.edu/archives/X11R5/contrib/
 
 MAINTAINER=	asami@FreeBSD.ORG
 
 USE_IMAKE=	yes
 
 .include <bsd.port.mk>
</verb></tscreen>

      <p>See if you can figure it out.  Don't worry about the contents
	of the <tt>&dollar;Id&dollar;</tt> line, it will be filled in
	automatically by CVS when the port is imported to our main
	ports tree.

      <sect2>
	<heading>Writing the description files</heading>

	<p>There are three required description files that are
	  required for any port, whether they actually package or not.
	  They are <tt>COMMENT</tt>, <tt>DESCR</tt>, and
          <tt>PLIST</tt>, and reside in the <tt>pkg</tt> subdirectory.

	<sect3>
	  <heading>COMMENT</heading>

	  <p>This is the one-line description of the port.  It is
	    recommended to not have the name of the package at the
	    beginning, as in:
<tscreen><verb>
A cat chasing a mouse all over the screen
</verb></tscreen>

	<sect3>
	  <heading>DESCR</heading>

	  <p>This is a longer description of the port.  One to a few
	    paragraphs concisely explaining what the port does is
	    sufficient.  Note: This is <em>not</em> a manual nor an
	    in-depth description on how to use or compile the port.
	    In particular, please do not just copy the <tt>README</tt>
	    file here, unless, of course, it's a concise description
	    of the port.

	  <p>It is recommended that you sign the name at the end of
	    this file, and also state the version number, as in:

<tscreen><verb>
This is a port of oneko, in which a cat chases a poor mouse all over
the screen.
 :
(etc.)
 :
This is version 1.1b.

- Satoshi
asami@cs.berkeley.edu
</verb></tscreen>

	<sect3>
	  <heading>PLIST</heading>

	  <p>This file lists all the files installed by the port.  It
	    is also called the `packing list' because the package is
	    generated by packing the files listed here.  The pathnames
	    are relative to the installation prefix (usually
	    <tt>/usr/local</tt> or <tt>/usr/X11R6</tt>).

	  <p>Here is a small example:

<tscreen><verb>
bin/oneko
man/man1/oneko.1.gz
lib/X11/app-defaults/Oneko
lib/X11/oneko/cat1.xpm
lib/X11/oneko/cat2.xpm
lib/X11/oneko/mouse.xpm
</verb></tscreen>

      <sect2>
	<heading>Creating the checksum file</heading>

	<p>Just type `<tt>make makesum</tt>'.  The ports make rules
	  will automatically generate the file <tt>files/md5</tt>.

      <sect2>
	<heading>Testing the port</heading>

	<p>You should make sure that the port rules do exactly what
	  you want it to do, including packaging up the port.  Try
	  doing `<tt>make install</tt>', `<tt>make package</tt>' and
	  then `<tt>pkg_delete -d &lt;pkgname&gt;</tt>' and see if all
	  the files are correctly deleted.  Then do a `<tt>pkg_add
	  &lt;pkgname&gt;.tgz</tt>' and see if everything re-appears
	  and works correctly.

      <sect2>
	<heading>Submitting the port</heading>

	<p>Now that you're happy with your port, the only thing
	  remaining is to put it in the main FreeBSD ports tree and
	  make everybody else happy about it too.  To accomplish this,
	  pack the necessary files (everything described in this
	  section -- in particular do <em>not</em> include the
	  original source tarball or the `<tt>work</tt>' subdirectory)
	  into a <tt>.tar.gz</tt> file, stick it in the directory
<tscreen><verb>
ftp://ftp.freebsd.org/pub/FreeBSD/incoming/
</verb></tscreen>
	  and send mail to <tt>ports@freebsd.org</tt>.  We will take a
	  look, get back to you if necessary, and put it in the tree.
	  Your name will also appear in the list of `Additional
	  FreeBSD contributors' on the FreeBSD Handbook and other
	  files.  Isn't that great?!? <tt>:)</tt>

    <sect1>
      <heading>Slow Porting</heading>

      <p>Ok, so it wasn't that simple, and the port required some
	modifications to get it to work.  In this section, we'll
	explain, step by step, how to modify it to get it to work with 
	the ports paradigm.

      <sect2>
	<heading>How things work</heading>

	<p>First, this is the sequence of events which occurs when the
	  user first types `<tt>make</tt>' in your port's directory,
	  and you may find that having <tt>bsd.port.mk</tt> in another
	  window while you read this really helps to understand it.

	<p>But don't worry if you don't really understand what
	  <tt>bsd.port.mk</tt> is doing, not many people
	  do... <tt>:&gt;</tt>

	<enum>
	  <item>The fetch target is run.  The fetch target is
	    responsible for making sure that the tarball exists
	    locally in <tt>&dollar;{DISTDIR}</tt>.  If fetch cannot
	    find the required files in <tt>&dollar;{DISTDIR}</tt> it
	    will look up the ftp-URL <tt>&dollar;{MASTER_SITES}</tt>,
	    which is set in the Makefile.  It will then attempt to
	    fetch the named distribution file with
	    <tt>&dollar;{NCFTP}</tt>, assuming that the requesting
	    site has direct access to the Internet.  If that succeeds,
	    it will save the file in <tt>&dollar;{DISTDIR}</tt> for
	    future use and proceed.

	  <item>The extract target is run.  It looks for your ports'
	    distribution file in <tt>&dollar;{DISTDIR}</tt> (typically
	    a gzip'd tarball) and unpacks it into a temporary
	    subdirectory specified by <tt>&dollar;{WRKDIR}</tt>
	    (defaults to <tt>work</tt>).

	  <item>The patch target is run.  First, any patches defined
	    in <tt>&dollar;{PATCHFILES}</tt> are applied.  Second, if
	    any patches are found in <tt>&dollar;{PATCHDIR}</tt>
	    (defaults to the <tt>patches</tt> subdirectory), they are
	    applied at this time in alphabetical order.

	  <item>The configure target is run.  This can do any one of
	    many different things.

	    <enum>

	      <item>If it exists, <tt>scripts/configure</tt> is run.

	      <item>If <tt>&dollar;{HAS_CONFIGURE}</tt> or
		<tt>&dollar;{GNU_CONFIGURE}</tt> is set,
		<tt>&dollar;{WRKSRC}/configure</tt> is run.

	      <item>If <tt>&dollar;{USE_IMAKE}</tt> is set,
		<tt>&dollar;{XMKMF}</tt> (default: `<tt>xmkmf
		  -a</tt>') is run.

	    </enum>

	  <item>The build target is run.  This is responsible for
	    descending into the ports' private working directory
	    (<tt>&dollar;{WRKSRC}</tt>) and building it.  If
	    <tt>&dollar;{USE_GMAKE}</tt> is set, GNU <tt>make</tt>
	    will be used, otherwise the system <tt>make</tt> will be
	    used.

	</enum>

	<p>The above are the default actions.  In addition, you can
	  define targets `<tt>pre-&lt;something&gt;</tt>' or
	  `<tt>post-&lt;something&gt;</tt>', or put scripts with those
	  names, in the <tt>scripts</tt> subdirectory, and they will
	  be run before or after the default actions are done.

	<p>For example, if you have a <tt>post-extract</tt> target
	  defined in your Makefile, and a file <tt>pre-build</tt> in
	  the <tt>scripts</tt> subdirectory, the
	  <tt>post-extract</tt> target will be called after the
	  regular extraction actions, and the <tt>pre-build</tt>
	  script will be executed before the default build rules are
	  done.  It is recommended that you use Makefile targets if
	  possible, because it will be easier for someone to figure
	  out what kind of non-default action the port requires.

	<p>The default actions are done by the <tt>bsd.port.mk</tt>
	  targets `<tt>do-&lt;something&gt;</tt>'.  For example, the
	  commands to extract a port are in the target
	  `<tt>do-extract</tt>'.  If you are not happy with the
	  default target, and you can't fix it by redefining the
	  `<tt>do-&lt;something&gt;</tt>' target in your Makefile.

	<p>Note that the `main' targets (e.g., <tt>extract</tt>,
	  <tt>configure</tt>, etc.) do nothing more than make sure all 
	  the stages up to that one is completed and call the real
	  targets or scripts, and they are not intended to be
	  changed.  If you want to fix the extraction, fix
	  <tt>do-extract</tt>, but never ever touch <tt>extract</tt>!

	<p>Now that you understand what goes on when the user types
	  `<tt>make</tt>', let's go through the recommended steps to
	  create the perfect port.

      <sect2>
	<heading>Getting the original sources</heading>

	<p>Get the original sources (normally) as a compressed tarball
	  (<tt>&lt;foo&gt;.tar.gz</tt> or <tt>&lt;foo&gt;.tar.Z</tt>)
	  and copy it into <tt>&dollar;{DISTDIR}</tt>.  Always use
	  <em>mainstream</em> sources when and where you can.

	<p>If you can't find a ftp site that is well-connected to the
	  net, or can only find sites that have irritatingly
	  non-standard formats, we can `house' it ourselves by putting
	  it on
<tscreen><verb>
ftp://freefall.freebsd.org/pub/FreeBSD/LOCAL_PORTS/
</verb></tscreen>
	  as the last resort.  Send mail to <tt>ports@freebsd.org</tt>
	  if you are not sure what to do.

	<p>If your port requires some additional `patches' that are
	  available on the Internet, fetch them too and put them in
	  <tt>&dollar;{DISTDIR}</tt>.  Don't worry if they come from
	  site other than where you got the the main source tarball,
	  we have a way to handle these situations (see the
	  description of <tt>&dollar;{PATCHFILES}</tt> below).

      <sect2>
	<heading>Modifying the port</heading>

	<p>Unpack a copy of the tarball in a private directory and
	  make whatever changes are necessary to get the port to
	  compile properly under the current version of FreeBSD.  Keep
	  <em>careful track</em> of everything you do, as you will be
	  automating the process shortly.  Everything, including the
	  deletion, addition or modification of files should be doable
	  using an automated script or patch file when your port is
	  finished.

	<p>If your port requires significant user
	  interaction/customization to compile or install, you should
	  take a look at one of Larry Wall's classic Configure scripts
	  and perhaps do something similar yourself.  The goal of the
	  new ports collection is to make each port as `plug-and-play'
	  as possible for the end-user while using a minimum of disk
	  space.

      <sect2>
	<heading>Patching</heading>

	<p>In the preparation of the port, files that have been added
	  or changed can be picked up with a recursive diff for later
	  feeding to patch.  This is the easiest kind of change to
	  make as it doesn't involve any mucking around with
	  configuration files.  Each set of patches you wish to apply
	  should be collected into a file named
	  `<tt>patch-&lt;xx&gt;</tt>' where <tt>&lt;xx&gt;</tt>
	  denotes the sequence in which the patches will be applied --
	  these are done in <em>alphabetical order</em>, thus
	  `<tt>aa</tt>' first, `<tt>ab</tt>' second and so on.  These
	  files should be stored in <tt>&dollar;{PATCHDIR}</tt>, from
	  where they will be automatically applied.  All patches
	  should be relative to <tt>&dollar;{WRKSRC}</tt> (generally
	  the directory your port's tarball unpacks itself into, that
	  being where the make is done).  To make fixes and upgrades
	  easier you should avoid having more than one patch fix the
	  same file (e.g., patch-ab and patch-ab both changing
	  <tt>&dollar;{WRKSRC}</tt>/foobar.c).

      <sect2>
	<heading>Configuring</heading>

	<p>Include any additional customization commands to your
	  <tt>configure</tt> script and save it in the
	  `<tt>scripts</tt>' subdirectory.  As mentioned above, you
	  can also do this as Makefile targets and/or scripts with the
	  name <tt>pre-configure</tt> or <tt>post-configure</tt>.

      <sect2>
	<heading>Handling user input</heading>

	<p>If your port requires user input to build, configure or
	  install, then set <tt>IS_INTERACTIVE</tt> in your Makefile.
	  This will allow `overnight builds' to skip your port if the
	  user sets the variable <tt>BATCH</tt> in his environment
	  (and if the user sets the variable <tt>INTERACTIVE</tt>,
	  then <em>only</em> those ports requiring interaction are
	  built).

    <sect1>
      <heading>Configuring the Makefile</heading>

      <p>Configuring the Makefile is pretty simple, and again we
	suggest that you look at existing examples before
	starting.  Consider the following problems in sequence as
	you design your new Makefile:

      <sect2>
	<heading>The original source</heading>

	<p>Does it live in <tt>&dollar;{DISTDIR}</tt> as a standard
	  gzip'd tarball?  If so, you can go on to the next step.  If
	  not, you should look at overriding any of the
	  <tt>&dollar;{EXTRACT_CMD}</tt>,
	  <tt>&dollar;{EXTRACT_BEFORE_ARGS}</tt>,
	  <tt>&dollar;{EXTRACT_AFTER_ARGS}</tt>,
	  <tt>&dollar;{EXTRACT_SUFX}</tt>, or
	  <tt>&dollar;{DISTFILE}</tt> variables, depending on how
	  alien a format your port's distribution file is.  (The most
	  common case is `<tt>EXTRACT_SUFX=.tar.Z</tt>', when the
	  tarball is condensed by regular compress, not gzip.)

	<p>In the worst case, you can simply create your own
	  `<tt>do-extract</tt>' target to override the default, though
	  this should be rarely, if ever, necessary.

      <sect2>
	<heading>DISTNAME</heading>
	<p>You should set <tt>&dollar;{DISTNAME}</tt> to be the base
	  name of your port.  The default rules expect the
	  distribution file list (<tt>&dollar;{DISTFILES}</tt>) to be
	  named
	  <tt>&dollar;{DISTFILE}&dollar;{EXTRACT_SUFX}</tt>
	  by default which, if it's a normal tarball, is going to be
	  something like:
<tscreen><verb>	
foozolix-1.0.tar.gz
</verb></tscreen>
	  for a setting of `<tt>DISTNAME=foozolix-1.0</tt>'.

	  The default rules also expect the tarball(s) to extract into
	  a subdirectory called <tt>work/&dollar;{DISTNAME}</tt>, e.g.
<tscreen><verb>	
work/foozolix-1.0/
</verb></tscreen>

	  All this behavior can be overridden, of course, it simply
	  represents the most common time-saving defaults.  For a port
	  requiring multiple distribution files, simply set
	  <tt>&dollar;{DISTFILES}</tt> explicitly.  If only a subset
	  of <tt>&dollar;{DISTFILES}</tt> are actual extractable
	  archives, then set them up in
	  <tt>&dollar;{EXTRACT_ONLY}</tt>, which will override the
	  <tt>&dollar;{DISTFILES}</tt> list when it comes to
	  extraction, and the rest will be just left in
	  <tt>&dollar;{DISTDIR}</tt> for later use.

      <sect2>
	<heading>CATEGORIES and KEYWORDS</heading>
	<p>When a package is created, it is put under
	  <tt>/usr/ports/packages/All</tt> and links are made from one
	  or more subdirectories of <tt>/usr/ports/packages</tt>.  The
	  names of these subdirectories are specified by the variable
	  <tt>&dollar;{CATEGORIES}</tt>.  It is intended to make life
	  easier for the user when he is wading through the pile of
	  packages on the ftp site or the CD-ROM.  Please take a look
	  at the existing categories (some of them have different
	  names from subdirectories of <tt>/usr/ports</tt>) and pick
	  the ones that are suitable for your port.  If your port
	  truly belongs to something that is different from all the
	  existing ones, you can even create a new category name.

	<p>If you want to add more information than just the category
	  names, add them to <tt>&dollar;{KEYWORDS}</tt>.  The value
	  of this variable defaults to that of
	  <tt>&dollar;{CATEGORIES}</tt>.  This is currently used only
	  as a field of the <tt>/usr/ports/INDEX</tt> file.

      <sect2>
	<heading>MASTER_SITES</heading>
	<p>If you have a ftp-URL pointing at the the original tarball,
	  record the directory containing the tarball in
	  <tt>&dollar;{MASTER_SITES}</tt>.  This will provide a backup
	  site, as well as a direct pointer to the original source
	  location.  Don't forget the trailing slash (<tt>/</tt>)!

 	<p>The make macros will try to use this specification for
	  grabbing the distribution file with <tt>&dollar;{NCFTP}</tt>
	  if they can't find it already on the system.

	<p>It is recommended that you put multiple sites on this list,
	  preferably from different continents.  This will safeguard
	  against wide-area network problems, and we are even planning
	  to add support for automatically determining the closest
	  master site and fetching from there!

      <sect2>
	<heading>PATCHFILES</heading>
	<p>If your port requires some additional patches that are
	  available by ftp, set <tt>&dollar;{PATCHFILES}</tt> to the
	  names of the files and <tt>&dollar;{PATCH_SITES}</tt> to the 
	  URL of the directory that contains them (the format is the
	  same as <tt>&dollar;{MASTER_SITES}</tt>).

	<p>If the patch is not relative to the top of the source tree
	  (i.e., <tt>&dollar;{WKRSRC}</tt>) because it contains some
	  extra pathnames, set <tt>&dollar;{PATCH_DIST_STRIP}</tt>
	  accordingly.  For instance, if all the pathnames in the
	  patch has an extra `<tt>foozolix-1.0/</tt>' in front of the
	  filenames, then set `<tt>PATCH_DIST_STRIP=-p1</tt>'.

	<p>Don't worry if the patches are compressed, they will be
	  decompressed automatically if the filenames end with
	  `<tt>.gz</tt>' or `<tt>.Z</tt>'.

      <sect2>
	<heading>MAINTAINER</heading>
	<p>Set your mail-address here.  Please. <tt>:)</tt>

      <sect2>
	<heading>Dependencies</heading>
	<p>Many ports depend on other ports.  There are five
	  variables that you can use to ensure that all the required
	  bits will be on the user's machine.
	<sect3>
	  <heading>LIB_DEPENDS</heading>
	  <p>This variable specifies the shared libraries this port
	    depends on.  It is a list of `<tt>lib:dir</tt>' pairs
	    where <tt>lib</tt> is the name of the shared library, and
	    <tt>dir</tt> is the directory in which to find it in case
	    it's not available.  For example,
<tscreen><verb>
LIB_DEPENDS=    tcl\\.7\\.:${PORTSDIR}/lang/tcl
</verb></tscreen>
	    will check for a shared tcl library with major version 7,
	    and descend into the <tt>lang/tcl</tt> subdirectory of
	    your ports tree to build and install it if it's not found.

	    Note that the <tt>lib</tt> part is just an argument given
	    to `<tt>ldconfig -r | grep</tt>', so periods should be
	    escaped by two backslashes like in the example above.
	<sect3>
	  <heading>RUN_DEPENDS</heading>
	  <p>This variable specifies executables this port depends on
	    during run-time.  It is a list of `<tt>exec:dir</tt>'
	    pairs where <tt>exec</tt> is the name of the executable,
	    and <tt>dir</tt> is the directory in which to find it in
	    case it's not available.  For example,
<tscreen><verb>
RUN_DEPENDS=   wish:${PORTSDIR}/x11/tk
</verb></tscreen>
	    will check for an executable called `<tt>wish</tt>', and
	    descend into the <tt>x11/tk</tt> subdirectory of your
	    ports tree to build and install it if it's not found.

	    The dependency is checked from within the <tt>install</tt>
	    target.  Also, the name of the dependency is put in to the 
	    package so that <tt>pkg_add</tt> will automatically
	    install it if it is not on the user's system.
	<sect3>
	  <heading>BUILD_DEPENDS</heading>
	  <p>This variable specifies executables this port requires to
	    build.  Like <tt>RUN_DEPENDS</tt>, it is a list of
	    `<tt>exec:dir</tt>' pairs.  For example,
<tscreen><verb>
BUILD_DEPENDS=   unzip:${PORTSDIR}/archivers/unzip
</verb></tscreen>
	    will check for an executable called `<tt>unzip</tt>', and
	    descend into the <tt>archivers/unzip</tt> subdirectory of
	    your ports tree to build and install it if it's not found.

	    Note that `build' here means everything from extracting to 
	    compilation.  The dependency is checked from within the
	    <tt>extract</tt> target.
	<sect3>
	  <heading>FETCH_DEPENDS</heading>
	  <p>This variable specifies executables this port requires to
	    fetch.  Like the previous two, it is a list of
	    `<tt>exec:dir</tt>' pairs.  For example,
<tscreen><verb>
FETCH_DEPENDS=   ncftp2:${PORTSDIR}/net/ncftp2
</verb></tscreen>
	    will check for an executable called `<tt>ncftp2</tt>', and
	    descend into the <tt>net/ncftp2</tt> subdirectory of
	    your ports tree to build and install it if it's not found.

	    The dependency is checked from within the <tt>fetch</tt>
	    target.
	<sect3>
	  <heading>DEPENDS</heading>
	  <p>If there is a dependency that doesn't fall into either of
	    the above four categories, or your port requires to have
	    the source of the other port extracted (i.e., having them
	    installed is not enough), then use this variable.  This is
	    just a list of directories, as there is nothing to check,
	    unlike the previous two.

      <sect2>
	<heading>Building mechanisms</heading>
	<p>If your package uses GNU <tt>make</tt>, set
	  `<tt>USE_GMAKE=yes</tt>'.  If your package uses GNU
	  <tt>configure</tt>, set `<tt>GNU_CONFIGURE=yes</tt>'.  If
	  you want to override the default GNU <tt>configure</tt>
	  arguments from `<tt>--prefix=&dollar;{PREFIX}</tt>' to
          something else, set those arguments in
	  <tt>&dollar;{CONFIGURE_ARGS}</tt>.

	<p>If your package uses <tt>imake</tt> (e.g. is an X
	  application that has an <tt>Imakefile</tt>), then set
	  `<tt>USE_IMAKE=yes</tt>'.  This will cause the configure
	  stage to automatically do an <tt>xmkmf -a</tt>.  If the
	  `<tt>-a</tt>' flag is a problem for your port, set
	  `<tt>XMKMF=xmkmf</tt>'.

	<p>If your port's source Makefile has something else than
	  `<tt>all</tt>' as the main build target, set
	  <tt>&dollar;{ALL_TARGET}</tt> accordingly.  Same goes for
	  `<tt>install</tt>' and <tt>&dollar;{INSTALL_TARGET}</tt>.

      <sect2>
	<heading>NO_INSTALL_MANPAGES</heading>
	<p>If the port uses imake but doesn't understand the
	  `<tt>install.man</tt>' target,
	  `<tt>NO_INSTALL_MANPAGES=yes</tt>' should be set.  In
	  addition, the author of the original port should be shot.

    <sect1>
      <heading>Licensing Problems</heading>
      <p>Some software packages have restrictive licenses or are in
        violation to the law (PKP's patent on public key crypto,
        ITAR (export of crypto software) to name just two of them).
        What we can do with them vary a lot, depending on the exact
        wordings of the respective licenses.

      <p>Note that it is your responsibility as a porter to read the
	licensing terms of the software and make sure that the FreeBSD
	project won't held accountable of violating them by
	redistributing the source or compiled binaries either via ftp
	or CD-ROM.  If in doubt, please contact
	<tt>ports@freebsd.org</tt>.

      <p>We usually get around this problem by setting
	<tt>&dollar;{NO_PACKAGE}</tt> in the Makefile, and not putting
	the distfile up for ftp.  However, for most cases, you should
	at least be able to make a port, so don't let the license
	scare you away!

      <p>Note: The GNU General Public License (GPL), both version 1
	and 2, shouldn't be a problem for ports.

      <p>Note: If you are a committer, make sure you update the
	<tt>ports/LEGAL</tt> file too.

    <sect1>
      <heading>* Upgrading</heading>
      <p>This section is still under construction, sorry.

    <sect1>
      <heading>Do's and Dont's</heading>

      <p>Here's a list of common do's and dont's that you encounter
	during the porting process.

      <sect2>
	<heading>WRKDIR</heading>
	<p>Don't leave anything valuable lying around in the
	  `<tt>work</tt>' subdirectory, `<tt>make clean</tt>' will
	  <em>nuke</em> it completely!  If you need auxiliary files
	  that aren't scripts or patches, put them in the subdirectory
	  `<tt>files</tt>' and use the <tt>post-extract</tt> target to
	  copy them to the `<tt>work</tt>' subdirectory.

      <sect2>
	<heading>Package information</heading>
	<p>Do install package information, i.e., the three files in
	  <tt>pkg</tt>.  Note that these files are not used only for
	  packaging anymore, and are <em>mandatory</em> now, even if
	  <tt>&dollar;{NO_PACKAGE}</tt> is set.

      <sect2>
	<heading>Compress manpages, strip binaries</heading>
	<p>Do compress manpages and strip binaries.  If the original
	  source already does that, fine; otherwise, you can add a
	  <tt>post-install</tt> rule to do it yourself.  Make sure
	  that you check the variable <tt>NOMANCOMPRESS</tt> that the
	  user can set in <tt>/etc/make.conf</tt> to disable man page
	  compression.  Here's an example:
<tscreen><verb>
 post-install:
	 strip ${PREFIX}/bin/xdl
 .if !defined(NOMANCOMPRESS)
	 gzip -9nf ${PREFIX}/man/man1/xdl.1
 .endif
</verb></tscreen>

	<p>Use the <tt>file</tt> command on the installed executable
	  to check whether the binary is stripped or not.  If it
	  doesn't say `not stripped', it is stripped.

      <sect2>
	<heading>Custom utilities</heading>
	<p>Don't rely on custom utilities in your local configure
	  script or anything -- they may not be there on the user's
	  system!  If you really need something else to be installed
	  before you can work, detect this from your configure script,
	  print a helpful message and exit with a non-zero status!  At
	  least you'll have given the user some idea of what's needed.
	  If the custom utility or package is actually part of the
	  ports tree, this should be dealt by the dependency mechanism
	  of ports.

	<p>Actually, if this utility is not part of the ports tree you
	  should probably make a port of this utility (this is how
	  many of the ports made it into the tree!). Depending on
	  something that is not part of the main FreeBSD distribution
	  or the ports tree is a bad idea, and the user should be able
	  to go to any subdirectory of <tt>/usr/ports</tt> and type
	  `<tt>make</tt>' and have that port, as well as everything it
	  requires, built automatically.

      <sect2>
	<heading>Feedback</heading>
	<p>Do send applicable changes/patches to the original
	  author/maintainer for inclusion in next release of the code.
	  This will only make your job that much easier for the next
	  release.

      <sect2>
	<heading>RCS strings</heading>
	<p>Don't put RCS strings in patches.  CVS will mangle them
	  when we put the files into the ports tree, and when we check
	  them out again, they will come out different and the patch
	  will fail.  RCS strings are surrounded by dollar
	  (`<tt>&dollar;</tt>') signs, and typically start with
	  `<tt>&dollar;Id</tt>' or `<tt>&dollar;RCS</tt>'.

      <sect2>
	<heading>Recursive diff</heading>
	<p>Using the recurse (`<tt>-r</tt>') option to <tt>diff</tt>
	  to generate patches is fine, but please take a look at the
	  resulting patches to make sure you don't have any
	  unnecessary junk in there.  In particular, diffs between two
	  backup files, Makefiles when the port uses imake or GNU
	  configure, etc., are unnecessary and should be deleted.
	  Also, if you had to delete a file, then you can do it in the
	  <tt>post-extract</tt> target rather than as part of the
	  patch.

      <sect2>
	<heading>PREFIX</heading>
	<p>Do try to make your port install relative to
	  <tt>&dollar;{PREFIX}</tt> in your Makefiles.  This will
	  normally be set to <tt>/usr/local</tt>, or
	  <tt>/usr/X11R6</tt> if <tt>&dollar;{USE_IMAKE}</tt> or
	  <tt>&dollar;{USE_X11}</tt> is set, though it can be
	  reassigned in your Makefile or in the users environment, if
	  need be.

	<p>Not hard-coding <tt>/usr/local</tt> anywhere in your
	  installation will make the port much more flexible and cater
	  to the needs of other sites.  Note that this doesn't count
	  for package `packing list' files since they have their own
	  scheme for relocating themselves and can be left independent
	  of <tt>&dollar;{PREFIX}</tt> unless the package is one that
	  hard-codes itself to a compiled-in location.

      <sect2>
      <heading>Subdirectories</heading>
	<p>Try to let the port put things in the right subdirectories
	  of <tt>&dollar;{PREFIX}</tt>.  Some ports lump everything
	  and put it in the subdirectory with the port's name, which is
	  incorrect.  Also, many ports put everything except binaries,
	  header files and manual pages in the a subdirectory of
	  `<tt>lib</tt>', which does not bode well with the BSD
	  paradigm.  Many of the files should me moved to one of the
	  following: `<tt>etc</tt>' (setup/configuration files),
	  `<tt>libexec</tt>' (executables started internally),
	  `<tt>sbin</tt>' (executables for superusers/managers) or
	  `<tt>share</tt>' (architecture independent files).  See
	  <tt>hier(7)</tt> for details, the rule governing
	  <tt>/usr</tt> pretty much applies to <tt>/usr/local</tt>
	  too.

      <sect2>
	<heading>ldconfig</heading>
	<p>If your port installs a shared library, add a
	  <tt>post-install</tt> target to your Makefile that runs
	  `<tt>/sbin/ldconfig -m</tt>' on the directory where the new
	  library is installed (usually <tt>&dollar;{PREFIX}/lib</tt>)
	  to register it into the shared library cache.

	<p>Also, add an <tt>@exec</tt> line to your <tt>pkg/PLIST</tt>
	  file so that a user who installed the package can start
	  using the shared library immediately.  This line should 
	  immediately follow the line for the shared library itself,
	  as in:
<tscreen><verb>
lib/libtcl.so.7.3
@exec /sbin/ldconfig -m %D/lib
</verb></tscreen>

	<p>Note: the `-m' option is new since 2.0.5 and
	  2.1.0-950726-SNAP, so don't be alarmed if it doesn't work on 
	  your machine.

	<p>Never, ever, <em>ever</em> add a line that says
	  `<tt>ldconfig</tt>' without any arguments to your Makefile
	  or pkg/PLIST.  This will reset the shared library cache to
	  the contents of <tt>/usr/lib</tt> only, and will royally
	  screw up the user's machine ("Help, xinit doesn't run
	  anymore after I install this port!").  Anybody who does this
	  will be shot and cut into 65,536 pieces by a rusty knife and
	  have his liver chopped out by a bunch of crows and will
	  eternally rot to death in the deepest bowels of hell (not
	  necessarily in that order)....

      <sect2>
	<heading>If you are stuck....</heading>
	<p>Do look at existing examples and the <tt>bsd.port.mk</tt>
	  file before asking us questions!  <tt>;)</tt>

	<p>Do ask us questions if you have any trouble!  Don't just
	  beat your head against a wall! <tt>:)</tt>

    <sect1>
      <heading>A Sample Makefile</heading>
      <p>Here is a sample Makefile that you can use to create a new
	port.  Make sure you remove all the extra comments (ones
	between brackets)!

      <p>It is recommended that you follow this format (ordering of
	variables, etc.).  Not all of the existing Makefiles are in
	this format (mostly old ones), but we are trying to uniformize
	how they look.  This format is designed so that the most
	important information is easy to locate.

<tscreen><verb>
 [the header...just to make it easier for us to identify the ports]
 # New ports collection makefile for:	xdvi
 # Version required:	2.2 [things like "1.5alpha" are fine here too]
 # Date created:		26 May 1995
 [this is the person who did the original port to FreeBSD, in particular, the
  person who wrote this Makefile]
 # Whom:			Satoshi Asami <asami@FreeBSD.ORG>
 #
 # $Id: porting.sgml,v 1.7 1995/10/07 04:31:35 jfieber Exp $
 [ ^^^^ don't worry about this...it will be automatically filled in by CVS when 
  it is committed to our repository]
 #
 
 [section to describe the package itself and main ftp site - DISTNAME
  is always first, followed by PKGNAME (if necessary), CATEGORIES,
  KEYWORDs (if necessary) and then MASTER_SITES, and optionally
  EXTRACT_SUFX or DISTFILES]
 DISTNAME=	xdvi
 PKGNAME=	xdvi-pl18
 CATEGORIES+=	printing
 [don't forget the trailing slash ("/")!]
 MASTER_SITES=	ftp://crl.dec.com/pub/X11/contrib/applications/
 [set this if the source is not in the standard ".tar.gz" form]
 EXTRACT_SUFX=	.tar.Z
 
 [section for distributed patches -- can be empty]
 PATCH_SITES=	ftp://ftp.sra.co.jp/pub/X11/japanese/
 PATCHFILES=	xdvi-18.patch1.gz xdvi-18.patch2.gz
 
 [maintainer; *mandatory*!  This is the person (preferably with commit
  privileges) who a user can contact for questions and bug reports - this
  person should be the porter or someone who can forward questions to the
  original porter reasonably promptly.  If you really don't want to have your
  address here, set it to "ports@FreeBSD.ORG".]
 MAINTAINER=	asami@FreeBSD.ORG
 
 [dependencies -- can be empty]
 RUN_DEPENDS=	gs:${PORTSDIR}/print/ghostscript
 LIB_DEPENDS=	Xpm\\.4\\.:${PORTSDIR}/graphics/xpm
 
 [this section is for other standard bsd.port.mk variables that don't belong to
  any of the above]
 [If it extracts to a directory other than ${DISTNAME}...]
 WRKSRC=		${WRKDIR}/xdvi-new
 [If it asks questions during configure, build, install...]
 IS_INTERACTIVE=	yes
 [If it requires "configure" in the distributed source directory to be run...]
 HAS_CONFIGURE=	yes
 [If it requires GNU make, not /usr/bin/make, to build...]
 USE_GMAKE=	yes
 [If it is an X application and requires "xmkmf -a" to be run...]
 USE_IMAKE=	yes
 [et cetera.]
 
 [non-standard variables to be used in the rules below]
 MY_FAVORITE_RESPONSE=	"yeah, right"
 
 [then the special rules, in the order they are called]
 pre-fetch:
	 i go fetch something, yeah
 
 post-patch:
	 i need to do something after patch, great
 
 pre-install:
	 and then some more stuff before installing, wow
 
 [and then the epilogue]
 .include <bsd.port.mk>
</verb></tscreen>

    <sect1>
      <heading>Package Names</heading>

      <p>The following are the conventions you should follow in
	naming your packages.  This is to have our package directory
	easy to scan, as there are already lots and lots of packages
	and users are going to turn away if they hurt their eyes!

      <p>If your <tt>&dollar;{DISTNAME}</tt> does not look like
	`<tt>&lt;name&gt;-&lt;version.string.numbers&gt;</tt>', set
	<tt>&dollar;{PKGNAME}</tt> to something in that format.

      <enum>
        <item>The `<tt>&lt;name&gt;</tt>' part should be all
	  lowercases, except for a really large package (with lots of
	  programs in it).  Things like XFree86 (yes there really is a
	  package of it, check it out) and ImageMagick fall into this
	  category.  Otherwise, convert the name (or at least the
	  first letter) to lowercase.  If the software in question
	  really is called that way, you can have numbers, hyphens and
	  underscores in the name too.

        <item>The version string should be a period-separated list of
	  integers and single lowercase alphabets.  The only exception
	  is the string `pl' (meaning `patchlevel'), which can be used
	  <em>only</em> when there are no major and minor version
	  numbers in the software.
      </enum>

      <p>Here are some (real) examples on how to convert a
	<tt>&dollar;{DISTNAME}</tt> into a suitable
	<tt>&dollar;{PKGNAME}</tt>:

<tscreen><verb>
DISTNAME	PKGNAME		Reason
mule-2.2.2	mule-2.2.2	no prob at all
XFree86-3.1.2	XFree86-3.1.2	ditto
EmiClock-1.0.2	emiclock-1.0.2	no uppercase names for single programs
gmod1.4		gmod-1.4	need hyphen after `<name>'
xmris.4.02	xmris-4.02	ditto
rdist-1.3alpha	rdist-1.3a	no strings like `alpha' allowed
es-0.9-beta1	es-0.9b1	ditto
v3.3beta021.src	jpeg-5a		what the heck was that anyway? ;)
tvtwm		tvtwm-pl11	version string always required
piewm		piewm-1.0	ditto
xvgr-2.10pl1	xvgr-2.10.1	`pl' allowed only when no maj/minor numbers
</verb></tscreen>

      <p>If there is absolutely no trace of version information in the
	original source and it is unlikely that the original author
	will ever release another version, just set the version string
	to `1.0' (like the piewm example above).  Otherwise, ask the
	original author or use the date string (`yy.mm.dd') as the
	version.

    <sect1>
      <heading>That's It, Folks!</heading>

      <p>Boy, this sure was a long tutorial, wasn't it?  Thanks for
	following us to here, really.

      <p>Well, now that you know how to do a port, let's go at it and
	convert everything in the world into ports!  That is the
	easiest way to start contributing to the FreeBSD Project! 
	<tt>:)</tt>