freebsd-dev/share/doc/handbook/ports.sgml

<!-- $FreeBSD$ -->
<!-- The FreeBSD Documentation Project -->

<sect><heading>The Ports collection<label id="ports"></heading>

<p><em>Contributed by &a.jraynard;.</em>

The FreeBSD Ports collection allows you to compile and install a very
wide range of applications with a minimum of effort. 

<p> For all the hype about open standards, getting a program to work
on different versions of Unix in the real world can be a tedious and
tricky business, as anyone who has tried it will know. You may be lucky
enough to find that the program you want will compile cleanly on your
system, install itself in all the right places and run flawlessly
``out of the box'', but this is unfortunately rather rare. With most
programs, you will find yourself doing a fair bit of head-scratching,
and there are quite a few programs that will result in premature
greying, or even chronic alopecia...

<p> Some software distributions have attacked this problem by
providing configuration scripts. Some of these are very clever, but
they have an unfortunate tendency to triumphantly announce that your
system is something you have never heard of and then ask you lots of
questions that sound like a final exam in system-level Unix
programming (``Does your system's gethitlist function return a const
pointer to a fromboz or a pointer to a const fromboz? Do you have
Foonix style unacceptable exception handling? And if not, why not?'').

<p> Fortunately, with the Ports collection, all the hard work involved
has already been done, and you can just type 'make install' and get a
working program.

<sect1><heading>Why have a Ports Collection?</heading>

<p>The base FreeBSD system comes with a very wide range of tools and
system utilities, but a lot of popular programs are not in the base
system, for good reasons:-

<enum>
<item>``I can not  live without x y and z on my system'' type programs
(eg a certain Lisp-based editor, or the mtools set of programs for
dealing with DOS floppy disks), because it is too subjective (many
people can not stand Emacs and/or never use DOS floppies and seem none
the worse for it).

<item>Too specialised to put in the base system (CAD, databases).

<item>Programs which fall into the ``I would not mind having a look at
that when I get a spare minute'' category, rather than system-critical
ones (some languages, perhaps).

<item>``Wow fab this is way cool'' fun type programs that could not
possibly be supplied with a serious operating system like FreeBSD ;-)

<item>However many programs you put in the base system, people will
always want more, and a line has to be drawn somewhere (otherwise
FreeBSD distributions would become absolutely enormous).
</enum>

<p> Obviously it would be unreasonable to expect everyone to port their
favourite programs by hand (not to mention a tremendous amount of
duplicated work), so the FreeBSD Project came up with an ingenious
way of using standard tools that would automate the process. 

<p> Incidentally, this is an excellent illustration of how ``the Unix way''
works in practice by combining a set of simple but very flexible tools
into something very powerful.

<sect1><heading> How does the Ports collection work?</heading>
<p>
Programs are typically distributed on the Internet as a 
<ref id="ports:tarball" name="tarball"> consisting of
a Makefile and the source code for the program and usually
some instructions (which are unfortunately not always as instructive
as they could be), with perhaps a configuration script. 
<p>
The standard scenario is that you FTP down the tarball, extract it 
somewhere, glance through the instructions, make any changes that seem 
necessary, run the configure script to set things up and use the standard 
`make' program to compile and install the program from the source.
<p>
FreeBSD ports still use the tarball mechanism, but use a 
<ref id="ports:skeleton" name="skeleton"> to hold the &quot;knowledge&quot; 
of how to get the program working on FreeBSD, rather than expecting the
user to be able to work it out. They also supply their own customised
<ref id="ports:makefile" name="Makefile">, so that almost every port
can be built in the same way.
<p>
If you look at a port skeleton (either on <htmlurl
url="file://localhost/usr/ports/shells/bash" name="your FreeBSD
system"> or <htmlurl
url="ftp://www.freebsd.org/pub/FreeBSD/ports/shells/bash" name="the
FTP site">) and expect to find all sorts of pointy-headed rocket
science lurking there, you may be disappointed by the one or two
rather unexciting-looking files and directories you find there.
(We will discuss in a minute how to go about <ref id="ports:getting"
name="Getting a port">).

<p>``How on earth can this do anything?'' I hear you cry. ``There
is not even any source code there!''

<p> Fear not, gentle reader, all will become clear (hopefully). Let's
see what happens if we try and install a port. I have chosen `bash', also
known as the Bourne-Again Shell, as that seems fairly typical.

<em>Note</em> if you are trying this at home, you will need to be root.

<verb>
 # cd /usr/ports/shells/bash
 # make install
 Checksums OK.
 ===>  Extracting for bash-1.14.5
 ===>  Patching for bash-1.14.5
 ===>  Applying FreeBSD patches for bash-1.14.5
 ===>  Configuring for bash-1.14.5
 ===>  Building for bash-1.14.5
 [lots and lots of compiler output here...]
 ===>  Installing for bash-1.14.5
 make -f bash-Makefile    bindir=/usr/local/bin  prefix=/usr/local install
 (cd ./documentation/; make  )
 rm -f builtins.txt
 nroff -man builtins.1 > builtins.txt
 install -c -o bin -g bin -m 555 bash /usr/local/bin/bash
 install -c -o bin -g bin -m 555 bashbug /usr/local/bin/bashbug
 ( cd ./documentation/ ; make   mandir=/usr/local/man/man1 man3dir=/usr/local/man/man3 infodir=/usr/local/info install )
 [ -d /usr/local/man/man1 ] || mkdir /usr/local/man/man1
 [ -d /usr/local/info ] || mkdir /usr/local/info
 ../support/install.sh -c -m 644 bash.1 /usr/local/man/man1
 ../support/install.sh -c -m 644 builtins.1 /usr/local/man/man1/bash_builtins.1
 ../support/install.sh -c -m 644 features.info /usr/local/info/bash.info
 gzip -9nf /usr/local/man/man1/bash.1 /usr/local/man/man1/bash_builtins.1
 ===>  Registering installation for bash-1.14.5
</verb>

<p> To avoid confusing the issue, I have slightly pruned the install
output, as well as completely removing the build output. If you tried
this yourself, you may well have got something like this at the start:-

<label id="ports:fetch">
<verb>
 >> bash-1.14.5.tar.gz doesn't seem to exist on this system.
 >> Attempting to fetch from ftp://slc2.ins.cwru.edu/pub/dist/.
</verb>

<p> The `make' program has noticed that you did not have a local copy
of the source code and tried to FTP it down so it could get the job
done (are you starting to feel impressed? 8-)). I already had the
source handy in my example, so it did not need to fetch it.

<p> Let's go through this and see what the `make' program was doing.

<enum>
<item> Locate the source code <ref id="ports:tarball"
name="tarball."> If it is not available locally, try to grab it from an
FTP site.

<item> Run a <ref id="ports:checksum" name="checksum"> test on the
tarball to make sure it has not been tampered with, accidentally
truncated, struck by neutrinos while in transit, etc.

<item> Extract the tarball into a temporary work directory.

<item> Apply any <ref id="ports:patch" name="patches"> needed to get
the source to compile and run under FreeBSD.

<item> Run any configuration script required by the build process and
correctly answer any questions it asks.

<item> (Finally!) Compile the code.

<item> Install the program executable and other supporting files, man
pages, etc. under the /usr/local hierarchy, where they will not get mixed
up with system programs. This also makes sure that all the ports you
install will go in the same place, instead of being flung all over
your system.

<item> Register the installation in a database. This means
that, if you do not like the program, you can cleanly <ref
id="ports:remove" name="remove"> all traces of it from your system.

</enum>

<p> See if you can match these steps to the make output. And if you
were not impressed before, you should be by now!

<sect1><heading>Getting a FreeBSD Port<label id="ports:getting"></heading>
<p>
There are two ways of getting hold of the FreeBSD port for a
program. One requires a <ref id="ports:cd" name="FreeBSD
CDROM">, the other involves using an <ref id="ports:inet"
name="Internet Connection.">

<sect2><heading>Compiling ports from CDROM<label id="ports:cd"></heading>
<p>
If you answered yes to the question ``Do you want to link the ports 
collection to your CDROM'' during the FreeBSD installation, the initial
setting up will already have been done for you.
<p>
If not, make sure the <em /FreeBSD/ CDROM is in the drive and mounted on, 
say, /cdrom. Then do

<verb>
 # mkdir /usr/ports
 # cd /usr/ports
 # ln -s /cdrom/ports/distfiles distfiles
</verb>

to enable the ports make mechanism to find the tarballs (it expects to
find them in /usr/ports/distfiles, which is why we sym-linked the
CDROM's tarball directory to there).
<p>
Now, suppose you want to install the gnats program from the databases
directory. Here is how to do it:-

<verb>
 # cd /usr/ports
 # mkdir databases
 # cp -R /cdrom/ports/databases/gnats databases
 # cd databases/gnats
 # make install
</verb>

Or if you are a serious database user and you want to compare all the
ones available in the Ports collection, do

<verb>
 # cd /usr/ports
 # cp -R /cdrom/ports/databases .
 # cd databases
 # make install
</verb>

(yes, that really is a dot on its own after the cp command and not a
mistake. It is Unix-ese for ``the current directory'')
<p>
and the ports make mechanism will automatically compile and install
all the ports in the databases directory for you!
<p>
If you do not like this method, here is a completely different way of
doing it:-
<p>
Create a "link tree" to it using the <tt>lndir(1)</tt> command that
comes with the <em>XFree86</em> distribution.  Find a location with
some free space and create a directory there, and make a symbolic link
from <tt>/usr/ports</tt> to that directory.  Then invoke the
<tt>lndir(1)</tt> command with the full pathname of the ``ports''
directory on the CDROM as an argument (this might be, for example,
something like: <tt>lndir /cdrom/ports</tt>).  Then you can build
ports directly off the CDROM by building them in the link tree you
have created.
<p>
Note that there are some ports for which we cannot provide the original
source in the CDROM due to licensing limitations.  In that case,
you will need to look at the section on <ref id="ports:inet"
name="Compiling ports using an Internet connection.">

<sect2><heading>Compiling ports from the Internet<label
id="ports:inet"></heading>
<p>
If you do not have a CDROM, or you want to make sure you get the very
latest version of the port you want, you will need to download the
<ref id="ports:skeleton" name="skeleton"> for the port. Now this 
might sound like rather a fiddly job
full of pitfalls, like downloading the patches into the pkg
sub-directory by mistake, but it is actually very easy. 
<p>
The key to it is that the FreeBSD FTP server can create on-the-fly
<ref id="ports:tarball" name="tarballs"> for you. Here is how it works,
with the gnats program in the databases directory as an example (the
bits in square brackets are comments, do not type them in if you are
trying this yourself!):-

<verb>
 # cd /usr/ports
 # mkdir databases
 # cd databases
 # ftp ftp.freebsd.org
 [log in as `ftp' and give your email address when asked for a
 password. Remember to use binary (aka image) mode!]
 > cd /pub/FreeBSD/ports/databases
 > get gnats.tar.gz		[tarballs up the gnats skeleton for us]
 > quit
 # tar xzf gnats.tar.gz		[extract the gnats skeleton]
 # cd gnats
 # make install			[build and install gnats]
</verb>

What happened here? We connected to the FTP server in the usual way
and went to its databases sub-directory. When we gave it the command
`get gnats.tar.gz', the FTP server <ref id="ports:tarball"
name="tarballed"> up the gnats directory for us and even went to the
trouble of compressing it before sending it so we could get our hands
on it a little quicker.
<p>
We then extracted the gnats skeleton and went into the gnats directory
to build the port. As we explained <ref id="ports:fetch"
name="earlier">, the make process noticed we did not have a copy of the
source locally, so it fetched one before extracting, patching and
building it.
<p>
Let's try something more ambitious now. Instead of getting a single
port skeleton, let's get a whole sub-directory, for example all the
database skeletons in the ports collection. It looks almost the same:-

<verb>
 # cd /usr/ports
 # ftp ftp.freebsd.org
 [log in as `ftp' and give your email address when asked for a
 password. Remember to use binary (aka image) mode!]
 > cd /pub/FreeBSD/ports
 > get databases.tar.gz		[tarballs up the databases directory for us]
 > quit
 # tar xzf databases.tar.gz	[extract all the database skeletons]
 # cd databases
 # make install			[build and install all the database ports]
</verb>

With half a dozen straightforward commands, we have now got a set of
database programs on our FreeBSD machine! All we did that was
different from getting a single port skeleton and building it was that
we got a whole directory at once, and compiled everything in it at
once. Pretty impressive, no?
<p>
If you expect to be installing more than one or two ports, it is
probably worth downloading all the ports directories - this involves
downloading 2 or 3MB, when they are compressed. However, don't get
carried away and type 'get ports.tar.gz' unless you are prepared to
download the distfiles directory as well - this contains the source
code for every single port and will take a very long time to download!

<sect1><heading>Skeletons<label id="ports:skeleton"></heading>
<p>
A team of compulsive hackers who have forgotten to eat in a frantic
attempt to make a deadline? Something unpleasant lurking in the FreeBSD 
attic? No, a skeleton here is a minimal framework that supplies everything
needed to make the ports magic work.

<sect2><heading>Makefile<label id="ports:makefile"></heading>
<p>
The most important component of a skeleton is the Makefile. This contains
various statements that specify how the port should be compiled and
installed. Here is the Makefile for bash:-

<verb>
 # New ports collection makefile for:	bash
 # Version required:     1.14.5
 # Date created:		21 August 1994
 # Whom:			jkh
 #
 # Makefile,v 1.13 1995/10/04 14:45:01 asami Exp
 #
 
 DISTNAME=       bash-1.14.5
 CATEGORIES=     shells
 MASTER_SITES=   ftp://slc2.ins.cwru.edu/pub/dist/
 
 MAINTAINER=     ache@FreeBSD.ORG
 
 post-install:
 .if !defined(NOMANCOMPRESS)
	 gzip -9nf ${PREFIX}/man/man1/bash.1 ${PREFIX}/man/man1/bash_builtins.1
 .endif
 
 .include &lt;bsd.port.mk>
</verb>

The lines beginning with a &quot;#&quot; sign are comments for the benefit
of human readers (as in most Unix script files).
<p>
`DISTNAME&quot; specifies the name of the <ref id="ports:tarball" 
name="tarball">, but without the extension.
<p>
`CATEGORIES&quot; states what kind of program this is.
<p>
`MASTER_SITES&quot; is the URL(s) of the master FTP site, which is
used to retrieve the <ref id="ports:tarball" name="tarball"> if it is not
available on the local system. This is a site which is regarded as
reputable, and is normally the one from which the program is officially 
distributed (in so far as any software is &quot;officially&quot; distributed
on the Internet).
<p>
`MAINTAINER&quot; is the email address of the person who is
responsible for updating the skeleton if, for example a new version
of the program comes out. (Note: The title of &quot;maintainer&quot;
is mainly an administrative one; it does <em /not/ mean the person
concerned is responsible for supporting the program. If you have any
<ref id="ports:kaput" name="problems with a port,"> please mail 
&a.ports; and <em /not/ the maintainer. Thank you!)
<p>
Skipping over the next few lines for a minute, the line 
<verb>
 .include <bsd.port.mk> 
</verb>
says that the other statements and commands 
needed for this port are in a standard file called 
`bsd.port.mk&quot;. As these are the same for all ports, there is
no point in duplicating them all over the place, so they are kept in a
single standard file.
<p>
This is probably not the place to go into a detailed examination of
how Makefiles work; suffice it to say that the lines starting with 
`post-install&quot; over-ride the instructions in bsd.port.mk
about what to do after installing the program, so that the man pages
can be compressed after they have been put in their final destination.

<sect2><heading>The files directory</heading>
<p>
The file containing the <ref id="ports:checksum" name="checksum"> for
the port is called &quot;md5&quot;, after the MD5 algorithm
used for ports checksums. It lives in a directory with the slightly
confusing name of &quot;files&quot;.
<p>
This directory can also contain other miscellaneous files that are required
by the port and do not belong anywhere else.

<sect2><heading>The patches directory</heading>
<p>
This directory contains the <ref id="ports:patch" name="patches"> needed
to make everything work properly under FreeBSD.

<sect2><heading>The pkg directory</heading>
<p>
This program contains three quite useful files:-

<itemize>
<item>
COMMENT - a one-line description of the program.

<item>
DESCR - a more detailed description.

<item>
PLIST - a list of all the files that will be created when the program is installed.
</itemize>

<sect1><heading>It does not work?!<label id="ports:kaput"></heading>

<p>Oh. You can do one of four (4) things :

<enum>
<item> Fix it yourself. Technical details can be found in
  <ref id="porting" name="Porting applications.">
<item> Gripe. This is done by e-mail *ONLY*! The people at Walnut Creek are
   in no way responsible for the functionality (or lack thereof) of the
   FreeBSD system as a whole, and especially the ports system, which
   is mainly contributed by 3rd parties. (If you do not believe me, check
   the catalogue, especially the line saying "We cannot offer tech-support
   on this product")

   The e-mail address is the &a.ports;. Please include 
   details of the port, where you got both the port source &amp; 
   distfile(s) from, and what the error was.

   Note: At time of writing, lang/Sather does not seem to work on Pentium
   machines due to the Intel Curse (aka the Floating Point Division Bug).
   Please do not tell us about this - gripe to Intel instead - it is their
   bug!

<item> Forget it. This is the easiest for most - very few of the programs in
   ports can be classified as `essential'!

<item> Grab the pre-compiled package from a ftp server. The ``master'' package
   collection is on FreeBSD's FTP server in the <htmlurl
   url="ftp://ftp.FreeBSD.org/pub/FreeBSD/packages/" 
name="packages directory.">

   though check your local mirror first, please!

   These are more likely to work (on the whole) than trying to compile from
   source, and a lot faster!  Use the <tt>pkg_add(1)</tt> 
dddprogram to install them to your system.

</enum>

<sect1><heading>I have this program that I would like to make into a port...</heading>

<p>Great! Please see the <ref id="porting:starting" name="guidelines">
for detailed instructions on how to do this.

<sect1><heading>Some Questions and Answers</heading>
<p>
<itemize>
<item>
Q. I thought this was going to be a discussion about modems??!
<p>
A. Ah. You must be thinking of the serial ports on the back of your
computer. We are using `port' here to mean the result of `porting' a
program from one version of Unix to another. (It is an unfortunate bad
habit of computer people to use the same word to refer to several
completely different things).

<item>
Q. I thought you were supposed to use packages to install extra
programs?
<p>
A. Yes, that is usually the quickest and easiest way of doing it.

<item>
Q. So why bother with ports then?
<p>
A. Several reasons:-

<enum>
<item> The licensing conditions on some software distributions
require that they be distributed as source code, not binaries.

<item> Some people do not trust binary distributions. At least with
source code you can (in theory) read through it and look for potential
problems yourself.

<item> If you have some local patches, you will need the source to add
them yourself.

<item> You might have opinions on how a program should be compiled
that differ from the person who did the package - some people have
strong views on what optimisation setting should be used, whether to
build debug versions and then strip them or not, etc. etc.

<item> Some people like having code around, so they can read it if
they get bored, hack around with it, borrow from it (licence terms
permitting, of course!) and so on.

<item> If you ain't got the source, it ain't software! ;-)
</enum>

<item><label id="ports:patch">
Q. What is a patch?
<p>
A. A patch is a small (usually) file that specifies how to go from one
version of a file to another. It contains text that says, in effect,
things like ``delete line 23'', ``add these two lines after line 468''
or ``change line 197 to this''. Also known as a `diff', since it is
generated by a program of that name.

<item><label id="ports:tarball">
Q. What is all this about tarballs?
<p>
A. It is a file ending in .tar.gz (with variations like .tar.Z, or
even .tgz if you are trying to squeeze the names into a DOS filesystem).
<p>
Basically, it is a directory tree that has been archived into a single
file (.tar) and then compressed (.gz). This technique was originally
used for <em /T/ape <em /AR/chives (hence the name `tar'), but it is a
widely used way of distributing program source code around the
Internet.
<p>
You can see what files are in them, or even extract them yourself, by
using the standard Unix tar program, which comes with the base FreeBSD
system, like this:-

<verb>
 tar tvzf foobar.tar.gz		# View contents of foobar.tar.gz
 tar xzvf foobar.tar.gz		# Extract contents into the current directory
</verb>

<item><label id="ports:checksum">
Q. And a checksum?
<p>
A. It is a number generated by adding up all the data in the file you
want to check. If any of the characters change, the checksum will no
longer be equal to the total, so a simple comparison will allow you to
spot the difference. (In practice, it is done in a more complicated way
to spot problems like position-swapping, which will not show up with a
simplistic addition).

<item>
Q. I did what you said for <ref id="ports:cd" name="compiling ports
from a CDROM"> and it worked great until I tried to install the kermit
port:-

<verb>
 # make install
 >> cku190.tar.gz doesn't seem to exist on this system.
 >> Attempting to fetch from ftp://kermit.columbia.edu/kermit/archives/.
</verb>

Why can it not be found? Have I got a dud CDROM?
<p>
A. The licensing terms for kermit do not allow us to put the tarball
for it on the CDROM, so you will have to fetch it by hand - sorry!
The reason why you got all those error messages was because you
were not connected to the Internet at the time. Once you have downloaded
it from any of the sites above, you can re-start the process (try and
choose the nearest site to you, though, to save your time and the
Internet's bandwidth).

<item>
Q. I did that, but when I tried to put it into /usr/ports/distfiles I
got some error about not having permission.
<p>
A. The ports mechanism looks for the tarball in /usr/ports/distfiles,
but you will not be able to copy anything there because it is sym-linked
to the CDROM, which is read-only. You can tell it to look somewhere
else by doing

<verb>
 DISTDIR=/where/you/put/it make install
</verb>

<item>
Q. Does the ports scheme only work if you have everything in
/usr/ports? My system administrator says I must put everything under
/u/people/guests/wurzburger, but it does not seem to work.
<p>
A. You can use the PORTSDIR and PREFIX variables to tell the ports
mechanism to use different directories. For instance,

<verb>
 PORTSDIR=/u/people/guests/wurzburger/ports make install
</verb>

will compile the port in /u/people/guests/wurzburger/ports and install
everything under /usr/local. 

<verb> 
 PREFIX=/u/people/guests/wurzburger/local make install
</verb>

will compile it in /usr/ports and install it in
/u/people/guests/wurzburger/local. 

And of course

<verb>
 PORTSDIR=.../ports PREFIX=.../local make install
</verb>

will combine the two (it is too long to fit on the page if I write it
in full, but I am sure you get the idea).
<p>
If you do not fancy typing all that in every time you install a port
(and to be honest, who would?), it is a good idea to put these variables
into your environment.

<item>
Q. I do not have a FreeBSD CDROM, but I would like to have all the tarballs
handy on my system so I do not have to wait for a download every time I
install a port. Is there an easy way to get them all at once?
<p>
A. To get every single tarball for the ports collection, do

<verb>
 # cd /usr/ports
 # make fetch
</verb>

For all the tarballs for a single ports directory, do

<verb>
 # cd /usr/ports/directory
 # make fetch
</verb>

and for just one port - well, I think you have guessed already.

<item>
Q. I know it is probably faster to fetch the tarballs from one of the
FreeBSD mirror sites close by. Is there any way to tell the port to
fetch them from servers other than ones listed in the MASTER_SITES?
<p>
A. Yes. If you know, for example, ftp.FreeBSD.ORG is much closer than
sites listed in MASTER_SITES, do as following example.
<verb>
 # cd /usr/ports/directory
 # make MASTER_SITE_OVERRIDE=ftp://ftp.FreeBSD.ORG/pub/FreeBSD/distfiles/ fetch
</verb>

<item>
Q. I want to know what files make is going to need before it tries to
pull them down.
<p>
A. 'make fetch-list' will display a list of the files needed for a port.

<item>
Q. Is there any way to stop the port from compiling? I want to do some
hacking on the source before I install it, but it is a bit tiresome having 
to watch it and hit control-C every time.
<p>
A. Doing 'make extract' will stop it after it has fetched and
extracted the source code.

<item>
Q. I am trying to make my own port and I want to be able to stop it
compiling until I have had a chance to see if my patches worked properly. 
Is there something like 'make extract', but for patches?
<p>
A. Yep, 'make patch' is what you want. And by the way, thank you for
your efforts!

<item>
Q. I have heard that some compiler options can cause bugs. Is this true?
How can I make sure that I compile ports with the right settings?
<p>
A. Yes, with version 2.6.3 of gcc (the version shipped with FreeBSD
2.1.0 and 2.1.5), the -O2 option could result in buggy code unless you
used the -fno-strength-reduce option as well. (Most of the ports don't
use -O2). You <em /should/ be able to specify the compiler options
used by something like

<verb>
 # CFLAGS='-O2 -fno-strength-reduce' make install
</verb>

or by editing /etc/make.conf, but this does not always seem to get
picked up. The surest way is to do 'make configure', then go into the
source directory and inspect the Makefiles by hand, but this can get
tedious if the source has lots of sub-directories, each with their own
Makefiles.

<item>
Q. There are so many ports it is hard to find the one I want. Is there a
list anywhere of what ports are available?
<p>
A. Look in the INDEX file in /usr/ports.

<item>
Q. I went to install the 'foo' port but the system suddenly stopped
and starting compiling the 'bar' port. What's going on?
<p>
A. The 'foo' port needs something that is supplied with 'bar' - for
instance, if 'foo' uses graphics, 'bar' might have a library with
useful graphics processing routines. Or 'bar' might be a tool that is
needed to compile the 'foo' port.

<item><label id="ports:remove"> 
Q. I installed the grizzle program from the ports and frankly it is a
complete waste of disk space. I want to delete it but I do not know
where it put all the files. Any clues?
<p>
A. No problem, just do

<verb>
 pkg_delete grizzle-6.5
</verb>
<item>

Q. Hang on a minute, you have to know the version number to use that
command. You do not seriously expect me to remember that, do you??
<p>
A. Not at all, you can find it out by doing

<verb>
 pkg_info -a | grep grizzle
</verb>

And it will tell you:-

<verb>
 Information for grizzle-6.5:
 grizzle-6.5 - the combined piano tutorial, LOGO interpreter and shoot 'em up arcade game.
</verb>

<item>
Q. Talking of disk space, the ports directory seems to be taking up
an awful lot of room. Is it safe to go in there and delete things?
<p>
A. Yes, if you have installed the program and are fairly certain you
will not need the source again, there is no point in keeping it hanging
around. The best way to do this is

<verb>
 # cd /usr/ports
 # make clean
</verb>

which will go through all the ports subdirectories and delete
everything except the skeletons for each port.
<item>
Q. I tried that and it still left all those tarballs or whatever you
called them in the distfiles directory. Can I delete those as well?
<p>
A. Yes, if you are sure you have finished with them, those can go as
well.

<item>
Q. I like having lots and lots of programs to play with. Is there any
way of installing all the ports in one go?
<p>
A. Just do

<verb>
 # cd /usr/ports
 # make install
</verb>

<item>
Q. OK, I tried that, but I thought it would take a very long time so I
went to bed and left it to get on with it. When I looked at the
computer this morning, it had only done three and a half ports. Did
something go wrong?
<p>
A. No, the problem is that some of the ports need to ask you questions
that we can not answer for you (eg ``Do you want to print on A4 or US
letter sized paper?'') and they need to have someone on hand to answer
them.

<item>
Q. I really do not want to spend all day staring at the monitor. Any
better ideas?
<p>
A. OK, do this before you go to bed/work/the local park:-

<verb>
 # cd /usr/ports
 # make -DBATCH install
</verb>

This will install every port that does <em /not/ require user
input. Then, when you come back, do

<verb>
 # cd /usr/ports
 # make -DIS_INTERACTIVE install
</verb>

to finish the job.

<item>
Q. At work, we are using frobble, which is in your ports collection,
but we have altered it quite a bit to get it to do what we need. Is
there any way of making our own packages, so we can distribute it more
easily around our sites?
<p>
A. No problem, assuming you know how to make patches for your changes:-

<verb>
 # cd /usr/ports/somewhere/frobble
 # make extract
 # cd work/frobble-2.8
 [Apply your patches]
 # cd ../..
 # make package
</verb>

<item>
Q. This ports stuff is really clever. I am desperate to find out how
you did it. What is the secret?
<p>
A. Nothing secret about it at all, just look at the bsd.ports.mk and
bsd.ports.subdir.mk files in your <htmlurl
url="file://localhost/usr/share/mk/" name="makefiles directory.">
(Note: readers with an aversion to intricate shell-scripts are advised
not to follow this link...)
</itemize>