[ghc-hetmet.git] / ghc / docs / users_guide / installing.sgml

<Chapter id="sec-installing-bin-distrib">
<Title>Installing from binary distributions</Title>
<IndexTerm><Primary>binary installations</Primary></IndexTerm>
<IndexTerm><Primary>installation, of binaries</Primary></IndexTerm>

<Para>
Installing from binary distributions is easiest, and recommended!
(Why binaries?  Because GHC is a Haskell compiler written in Haskell,
so you've got to &ldquo;bootstrap&rdquo; it, somehow.  We provide
machine-generated C-files-from-Haskell for this purpose, but it's
really quite a pain to use them.  If you must build GHC from its
sources, using a binary-distributed GHC to do so is a sensible way to
proceed. For the other <Literal>fptools</Literal> programs, many are written in Haskell,
so binary distributions allow you to install them without having a Haskell compiler.)
</Para>

<Para>This guide is in two parts: installing on Unix-a-likes, and installing on Windows.</Para>


<Sect1><Title>Installing on Unix-a-likes</Title>

<Sect2>
<Title>Bundle structure</Title>

<Para>
<IndexTerm><Primary>bundles of binary stuff</Primary></IndexTerm>
</Para>

<Para>
Binary distributions come in &ldquo;bundles,&rdquo; one bundle per file called
<Literal>&lt;bundle&gt;-&lt;platform&gt;.tar.gz</Literal>.  (See the building guide for the definition of a platform.)  Suppose that you untar a binary-distribution bundle, thus:
</Para>

<Para>

<Screen>
% cd /your/scratch/space
% gunzip &#60; ghc-x.xx-sun-sparc-solaris2.tar.gz | tar xvf -</Screen>

</Para>

<Para>
Then you should find a single directory, <Literal>fptools</Literal>, with the following
structure:
</Para>

<Para>
<IndexTerm><Primary>binary distribution, layout</Primary></IndexTerm>
<IndexTerm><Primary>directory layout (binary distributions)</Primary></IndexTerm>
<VariableList>

<VarListEntry>
<Term><Literal>Makefile.in</Literal></Term>
<ListItem>
<Para>
the raw material from which the <Literal>Makefile</Literal>
will be made (<Xref LinkEnd="sec-install">).
</Para>
</ListItem></VarListEntry>
<VarListEntry>
<Term><Literal>configure</Literal></Term>
<ListItem>
<Para>
the configuration script (<Xref LinkEnd="sec-install">).
</Para>
</ListItem></VarListEntry>
<VarListEntry>
<Term><Literal>README</Literal></Term>
<ListItem>
<Para>
Contains this file summary.
</Para>
</ListItem></VarListEntry>
<VarListEntry>
<Term><Literal>INSTALL</Literal></Term>
<ListItem>
<Para>
Contains this description of how to install
the bundle.
</Para>
</ListItem></VarListEntry>
<VarListEntry>
<Term><Literal>ANNOUNCE</Literal></Term>
<ListItem>
<Para>
The announcement message for the bundle.
</Para>
</ListItem></VarListEntry>
<VarListEntry>
<Term><Literal>NEWS</Literal></Term>
<ListItem>
<Para>
release notes for the bundle&mdash;a longer version
of <Literal>ANNOUNCE</Literal>.  For GHC, the release notes are contained in the User
Guide and this file isn't present.
</Para>
</ListItem></VarListEntry>
<VarListEntry>
<Term><Literal>bin/&lt;platform&gt;</Literal></Term>
<ListItem>
<Para>
contains platform-specific executable
files to be invoked directly by the user.  These are the files that
must end up in your path.
</Para>
</ListItem></VarListEntry>
<VarListEntry>
<Term><Literal>lib/&lt;platform&gt;/</Literal></Term>
<ListItem>
<Para>
contains platform-specific support
files for the installation.  Typically there is a subdirectory for
each <Literal>fptools</Literal> project, whose name is the name of the project with its
version number.  For example, for GHC there would be a sub-directory
<Literal>ghc-x.xx</Literal>/ where <Literal>x.xx</Literal> is the version number of GHC in the bundle.
</Para>

<Para>
These sub-directories have the following general structure:
</Para>

<Para>
<VariableList>

<VarListEntry>
<Term><Literal>libHS.a</Literal> etc:</Term>
<ListItem>
<Para>
supporting library archives.
</Para>
</ListItem></VarListEntry>
<VarListEntry>
<Term><Literal>ghc-iface.prl</Literal> etc:</Term>
<ListItem>
<Para>
support scripts.
</Para>
</ListItem></VarListEntry>
<VarListEntry>
<Term><Literal>import/</Literal></Term>
<ListItem>
<Para>
<IndexTerm><Primary>Interface files</Primary></IndexTerm> (<Literal>.hi</Literal>) for the prelude.
</Para>
</ListItem></VarListEntry>
<VarListEntry>
<Term><Literal>include/</Literal></Term>
<ListItem>
<Para>
A few C <Literal>&num;include</Literal> files.
</Para>
</ListItem></VarListEntry>
</VariableList>
</Para>
</ListItem></VarListEntry>
<VarListEntry>
<Term><Literal>share/</Literal></Term>
<ListItem>
<Para>
contains platform-independent support files
for the installation.  Again, there is a sub-directory for each
<Literal>fptools</Literal> project.
</Para>
</ListItem></VarListEntry>
<VarListEntry>
<Term><Literal>info/</Literal></Term>
<ListItem>
<Para>
contains Emacs info documentation files (one
sub-directory per project).
</Para>
</ListItem></VarListEntry>
<VarListEntry>
<Term><Literal>html/</Literal></Term>
<ListItem>
<Para>
contains HTML documentation files (one
sub-directory per project).
</Para>
</ListItem></VarListEntry>
<VarListEntry>
<Term><Literal>man/</Literal></Term>
<ListItem>
<Para>
contains Unix manual pages.
</Para>
</ListItem></VarListEntry>
</VariableList>
</Para>

<Para>
This structure is designed so that you can unpack multiple bundles
(including ones from different releases or platforms) into a single
<Literal>fptools</Literal> directory
<FOOTNOTE>

<Para>
this doesn't work at the
moment
</Para>

</FOOTNOTE>
:
</Para>

<Para>

<Screen>
% cd /your/scratch/space
% gunzip &#60; ghc-x.xx-sun-sparc-solaris2.tar.gz | tar xvf -
% gunzip &#60; happy-x.xx-sun-sparc-sunos4.tar.gz | tar xvf -</Screen>

</Para>

<Para>
When you do multiple unpacks like this, the top level <Literal>Makefile</Literal>,
<Literal>README</Literal>, and <Literal>INSTALL</Literal> get overwritten each time.
That's fine&mdash;they should be the same.  Likewise, the
<Literal>ANNOUNCE-&lt;bundle&gt;</Literal> and <Literal>NEWS-&lt;bundle&gt;</Literal>
files will be duplicated across multiple platforms, so they will be
harmlessly overwritten when you do multiple unpacks.  Finally, the
<Literal>share/</Literal> stuff will get harmlessly overwritten when you do
multiple unpacks for one bundle on different platforms.
</Para>

<Sect3 id="sec-install">
<Title>Installing</Title>

<Para>
OK, so let's assume that you have unpacked your chosen bundles into a
scratch directory <Literal>fptools</Literal>. What next? Well, you will at least need
to run the <Literal>configure</Literal><IndexTerm><Primary>configure</Primary></IndexTerm> script by changing your
directory to <Literal>fptools</Literal> and typing <Literal>./configure</Literal>.  That should convert
<Literal>Makefile.in</Literal> to <Literal>Makefile</Literal>.
</Para>

<Para>
<IndexTerm><Primary>installing in-place</Primary></IndexTerm>
<IndexTerm><Primary>in-place installation</Primary></IndexTerm>
You can now either start using the tools <Emphasis>in-situ</Emphasis> without going
through any installation process, just type <Literal>make in-place</Literal> to set the
tools up for this. You'll also want to add the path which <Literal>make</Literal> will
now echo to your <Literal>PATH</Literal> environment variable. This option is useful if
you simply want to try out the package and/or you don't have the
necessary privileges (or inclination) to properly install the tools
locally. Note that if you do decide to install the package `properly'
at a later date, you have to go through the installation steps that
follows.
</Para>

<Para>
To install an <Literal>fptools</Literal> package, you'll have to do the following:
</Para>

<Para>

<OrderedList>
<ListItem>

<Para>
 Edit the <Literal>Makefile</Literal> and check the settings of the following variables:

<IndexTerm><Primary>directories, installation</Primary></IndexTerm>
<IndexTerm><Primary>installation directories</Primary></IndexTerm>

<VariableList>

<VarListEntry>
<Term><Literal>platform</Literal></Term>
<ListItem>
<Para>
the platform you are going to install for.
</Para>
</ListItem></VarListEntry>
<VarListEntry>
<Term><Literal>bindir</Literal></Term>
<ListItem>
<Para>
the directory in which to install user-invokable
binaries.
</Para>
</ListItem></VarListEntry>
<VarListEntry>
<Term><Literal>libdir</Literal></Term>
<ListItem>
<Para>
the directory in which to install
platform-dependent support files.
</Para>
</ListItem></VarListEntry>
<VarListEntry>
<Term><Literal>datadir</Literal></Term>
<ListItem>
<Para>
the directory in which to install
platform-independent support files.
</Para>
</ListItem></VarListEntry>
<VarListEntry>
<Term><Literal>infodir</Literal></Term>
<ListItem>
<Para>
the directory in which to install Emacs info
files.
</Para>
</ListItem></VarListEntry>
<VarListEntry>
<Term><Literal>htmldir</Literal></Term>
<ListItem>
<Para>
the directory in which to install HTML
documentation.
</Para>
</ListItem></VarListEntry>
<VarListEntry>
<Term><Literal>dvidir</Literal></Term>
<ListItem>
<Para>
the directory in which to install DVI
documentation.
</Para>
</ListItem></VarListEntry>
</VariableList>

The values for these variables can be set through invocation of the
<Command>configure</Command><IndexTerm><Primary>configure</Primary></IndexTerm> script that comes with the distribution,
but doing an optical diff to see if the values match your expectations
is always a Good Idea.

<Emphasis>Instead of running <Command>configure</Command>, it is perfectly OK to copy
<Filename>Makefile.in</Filename> to <Filename>Makefile</Filename> and set all these variables
directly yourself.  But do it right!</Emphasis>

</Para>
</ListItem>
<ListItem>

<Para>
Run <Literal>make install</Literal>.  This <Emphasis> should</Emphasis> work with ordinary Unix
<Literal>make</Literal>&mdash;no need for fancy stuff like GNU <Literal>make</Literal>. 

</Para>
</ListItem>
<ListItem>

<Para>
<Literal>rehash</Literal> (t?csh or zsh users), so your shell will see the new
stuff in your bin directory.

</Para>
</ListItem>
<ListItem>

<Para>
 Once done, test your &ldquo;installation&rdquo; as suggested in 
<XRef LinkEnd="sec-GHC-test">.  Be sure to use a <Literal>-v</Literal>
option, so you can see exactly what pathnames it's using.

If things don't work as expected, check the list of know pitfalls in
the building guide.
</Para>
</ListItem>

</OrderedList>

</Para>

<Para>
<IndexTerm><Primary>link, installed as ghc</Primary></IndexTerm>
When installing the user-invokable binaries, this installation
procedure will install GHC as <Literal>ghc-x.xx</Literal> where <Literal>x.xx</Literal> is the version
number of GHC.  It will also make a link (in the binary installation
directory) from <Literal>ghc</Literal> to <Literal>ghc-x.xx</Literal>.  If you install multiple versions
of GHC then the last one &ldquo;wins&rdquo;, and &ldquo;<Literal>ghc</Literal>&rdquo; will invoke the last
one installed.  You can change this manually if you want.  But
regardless, <Literal>ghc-x.xx</Literal> should always invoke GHC version <Literal>x.xx</Literal>.
</Para>

</Sect3>


<Sect3>
<Title>What bundles there are</Title>

<Para>
<IndexTerm><Primary>bundles, binary</Primary></IndexTerm>
There are plenty of &ldquo;non-basic&rdquo; GHC bundles.  The files for them are
called <Literal>ghc-x.xx-&lt;bundle&gt;-&lt;platform&gt;.tar.gz</Literal>, where
the <Literal>&lt;platform&gt;</Literal> is as above, and <Literal>&lt;bundle&gt;</Literal> is one
of these:
</Para>

<Para>
<VariableList>

<VarListEntry>
<Term><Literal>prof</Literal>:</Term>
<ListItem>
<Para>
Profiling with cost-centres.  You probably want this.
<IndexTerm><Primary>profiling bundles</Primary></IndexTerm>
<IndexTerm><Primary>bundles, profiling</Primary></IndexTerm>
</Para>
</ListItem></VarListEntry>
<VarListEntry>
<Term><Literal>par</Literal>:</Term>
<ListItem>
<Para>
Parallel Haskell features (sits on top of PVM).
You'll want this if you're into that kind of thing.
<IndexTerm><Primary>parallel bundles</Primary></IndexTerm>
<IndexTerm><Primary>bundles, parallel</Primary></IndexTerm>
</Para>
</ListItem></VarListEntry>
<VarListEntry>
<Term><Literal>gran</Literal>:</Term>
<ListItem>
<Para>
The &ldquo;GranSim&rdquo; parallel-Haskell simulator
(hmm&hellip; mainly for implementors).
<IndexTerm><Primary>bundles, gransim</Primary></IndexTerm>
<IndexTerm><Primary>gransim bundles</Primary></IndexTerm>
</Para>
</ListItem></VarListEntry>
<VarListEntry>
<Term><Literal>ticky</Literal>:</Term>
<ListItem>
<Para>
&ldquo;Ticky-ticky&rdquo; profiling; very detailed
information about &ldquo;what happened when I ran this program&rdquo;&mdash;really
for implementors.
<IndexTerm><Primary>bundles, ticky-ticky</Primary></IndexTerm>
<IndexTerm><Primary>ticky-ticky bundles</Primary></IndexTerm>
</Para>
</ListItem></VarListEntry>
</VariableList>
</Para>

<Para>
One likely scenario is that you will grab <Emphasis>two</Emphasis>
binary bundles&mdash;basic, and profiling.  We don't usually make the
rest, although you can build them yourself from a source distribution.
</Para>

</Sect3>

<Sect3 id="sec-GHC-test">
<Title>Testing that GHC seems to be working
</Title>

<Para>
<IndexTerm><Primary>testing a new GHC</Primary></IndexTerm>
</Para>

<Para>
The way to do this is, of course, to compile and run <Emphasis>this</Emphasis> program
(in a file <Literal>Main.hs</Literal>):
</Para>

<Para>

<ProgramListing>
main = putStr "Hello, world!\n"
</ProgramListing>

</Para>

<Para>
Compile the program, using the <Literal>-v</Literal> (verbose) flag to verify that
libraries, etc., are being found properly:

<Screen>
% ghc -v -o hello Main.hs</Screen>

</Para>

<Para>
Now run it:

<Screen>
% ./hello
Hello, world!</Screen>

</Para>

<Para>
Some simple-but-profitable tests are to compile and run the notorious
<Literal>nfib</Literal><IndexTerm><Primary>nfib</Primary></IndexTerm> program, using different numeric types.  Start with
<Literal>nfib :: Int -&gt; Int</Literal>, and then try <Literal>Integer</Literal>, <Literal>Float</Literal>, <Literal>Double</Literal>,
<Literal>Rational</Literal> and perhaps the overloaded version.  Code for this is
distributed in <Literal>ghc/misc/examples/nfib/</Literal> in a source distribution.
</Para>

<Para>
For more information on how to &ldquo;drive&rdquo; GHC, either do <Literal>ghc -help</Literal> or
consult the User's Guide (distributed in several pre-compiled formats
with a binary distribution, or in source form in
<Literal>ghc/docs/users&lowbar;guide</Literal> in a source distribution).
</Para>

</Sect3>

</Sect2>

</Sect1>


<Sect1><Title>Installing on Windows</Title>

<Para>
Getting the Glasgow Haskell Compiler(GHC) to run on Windows95/98 or
Windows NT4 platforms can be a bit of a trying experience. This document
tries to simplify the task by enumerating the steps you need to
follow in order to set up and configure your machine to run GHC (at
least that's the intention ;-)
</Para>

<Sect2><Title>System requirements</Title>

<Para>
An installation of GHC requires ca. 70M of disk space. The size of the
installed GHC distribution is just(!) 17M, the rest is needed by
supporting software.
</Para>

<Para>
To run GHC comfortably, your machine should have at least 32M of memory.
</Para>

</Sect2>


<Sect2><Title>Your environment variables</Title>

<Para>
Much of the Unixy stuff below involves setting environment variables.  
This section summarises  how to set these variables on a Windows machine, in
case you don't know alread.y
On WinNT/Win2k, to edit your <Constant>PATH</Constant> variable (for example),
do the following:
</Para>

<ItemizedList>
<ListItem><Para>Press Start/Settings/Control Panels</Para></ListItem>
<ListItem><Para>Double-click System</Para></ListItem>
<ListItem><Para>Press Advanced</Para></ListItem>
<ListItem><Para>Press Environment Variables</Para></ListItem>
<ListItem><Para>Under System Variables, select PATH</Para></ListItem>
<ListItem><Para>Press Edit</Para></ListItem>
<ListItem><Para>Add "<Filename>;C:/whatever/</Filename>" to the end of the string (for example)</Para></ListItem>
<ListItem><Para>Press OK</Para></ListItem>
</ItemizedList>

<Para>
Some environment variables are &ldquo;user variables&rdquo; and
some are &ldquo;system variables&rdquo;.  I'm not sure of the difference
but both are changed though the same dialogue.
</Para>

<Para>
In addition, when running a Cygwin (see <XRef LinkEnd="sec-required">) shell
you can set environment variables in your <Filename>.bashrc</Filename> file.
But it is better to set your environment variables from the
control panel (they get inherited by bash) because then they are visible
to applications that aren't started by bash.  For example,
when you're invoking CVS (and ssh) via Emacs keybindings;
it invokes <Filename>cvs.exe</Filename> without going via bash.
</Para>

<Para>
On a Win9x machine you need to edit <Filename>autoexec.bat</Filename> using
<Filename>Windows/system/Sysedit</Filename>.  You need to reboot to make
the new settings take effect.
</Para>

</Sect2>


<Sect2 id="sec-required"><Title>Software required</Title>

<Para>
You need two chunks of software other than GHC itself: the Cygwin toolchain, and Perl.  Here's how to get and install them.
</Para>

<Sect3><Title>The cygwin toolchain (beta20.1)</Title>

<Para>
GHC depends at the moment on the cygwin tools to operate, which
dresses up the Win32 environment into something more UNIX-like.
(notably, it provides <Command>gcc</Command>, <Command>as</Command> and <Command>ld</Command>),
so you'll need to install these tools first. You also need
Cygwin to use CVS.
</Para>

<Para>
Important grungy information about Cygwin:
</Para>

<ItemizedList>

<ListItem>
<Para>
Cygwin doesn't deal well with filenames that include
spaces. "<Filename>Program Files</Filename>" and "<Filename>Local files</Filename>" are
common gotchas.
</Para>
</ListItem>

<ListItem>
<Para>
Cygwin implements a symbolic link as a text file with some
magical text in it.  So programs that don't use Cygwin's
I/O libraries won't recognise such files as symlinks.  
In particular, programs compiled by GHC are meant to be runnable
without having Cygwin, so they don't use the Cygwin library, so
they don't recognise symlinks.
</Para>
</ListItem>

</ItemizedList>

<Para>
Here's how to install Cygwin.
</Para>

<ItemizedList>

<ListItem>
<Para>
Download cygwin, beta20.1 (<filename>full.exe</filename>) from
<ULink URL="http://sourceware.cygnus.com/cygwin/">sourceware.cygnus.com</ULink>
Install this somewhere locally.
</Para>
</ListItem>

<ListItem>
<Para>
Create the following directories (if they aren't already there):
</Para>

<ItemizedList>
<ListItem><Para><Filename>c:/etc</Filename></Para></ListItem>
<ListItem><Para><Filename>c:/bin</Filename></Para></ListItem>
<ListItem><Para><Filename>c:/usr/local/bin</Filename></Para></ListItem>
</ItemizedList>

<Para>
(using <Command>mkdir -p /bin</Command>, etc.)
</Para>
</ListItem>

<ListItem>
<Para>
Copy <Filename>bash.exe</Filename> from the <Filename>bin</Filename>
directory of the cygwin tree
(<Filename>cygwin-b20/H-i586-cygwin32/bin/bash.exe</Filename>) to
<Filename>/bin</Filename> as <Filename>sh.exe</Filename>.  You might
think that it was easier to use bash directly from it original Cygwin
directory, but (a) some UNIX utils have got
<Filename>/bin/sh</Filename> hardwired in, and (b) the path following
<Literal>#!</Literal> is limited to 32 characters.
</Para>
</ListItem>

<ListItem>
<Para>
If you're an Emacs user and want to be able to run <Command>bash</Command>
from within a shell buffer, see the <ULink URL="http://www.cs.washington.edu/homes/voelker/ntemacs.html">NT Emacs home page</ULink> for
instructions on how to set this up.
</Para>
</ListItem>

</ItemizedList>

<Para>
The following environment variables must be set:
</Para>

<Para>
<InformalTable>
<TGroup cols="2">
<ColSpec Align="Left" Colsep="0">
<ColSpec Align="Left" Colsep="0">
<TBody>

<Row>
<Entry><Constant>PATH</Constant></Entry>
<Entry>System</Entry>
<Entry><Para>
Add <Filename>C:\cygnus\cygwin-b20\H-i586-cygwin32\bin</Filename>.
<Command>bash</Command> needs this, and when it is invoked from <Filename>/bin</Filename> it can't
find it. <Filename>c:/bin</Filename> and <Filename>c:/usr/local/bin</Filename> should also be added.
</Para></Entry>
</Row>

<Row>
<Entry><Constant>SHELL</Constant></Entry>
<Entry>User</Entry>
<Entry><Para>
<Filename>c:/bin/sh</Filename>.
</Para></Entry>
</Row>

<Row>
<Entry><Constant>HOME</Constant></Entry>
<Entry>User</Entry>
<Entry><Para>
Set to point to your home directory.  This is where, for example,
<Command>bash</Command> will look for your <Filename>.bashrc</Filename>
file.
</Para></Entry>
</Row>

<Row>
<Entry><Constant>MAKE_MODE</Constant></Entry>
<Entry>User</Entry>
<Entry><Para>
Set to <Literal>UNIX</Literal>.  If you don't do
this you get very weird messages when you type `<Command>make</Command>', such as:
</Para><Screen>
/c: /c: No such file or directory</Screen></Entry>
</Row>

<Row>
<Entry><Constant>TMPDIR</Constant></Entry>
<Entry>User</Entry>
<Entry><Para>
Set to <Filename>c:/tmp</Filename>. For some reason, Win2k invisibly sets
this variable to point to a temporary directory in your profile, that
contains embedded spaces.  If GHC sees the <Constant>TMPDIR</Constant>
variable set, it tries to use it for temporary files, but Cygwin
doesn't grok filenames with spaces, so disaster results.
</Para><Para>
Furthermore, it seems that <Constant>TMPDIR</Constant> must be set to a directory
in the same file system in which you invoke GHC.  Otherwise you get very werid messages
when you invoke GHC, such as:
<Screen>
does not exist
Action: openFile
Reason: file does not exist /tmp/ghc11068.cpp</Screen>
We think this is due to a bug in Cygwin.
</Para></Entry>
</Row>
</TBody>

</TGroup>
</InformalTable>
</Para>

</Sect3>


<Sect3><Title>Perl5</Title>

<Para>
The driver script is written in Perl, so you'll need to have this
installed too. However, the ghc binary distribution includes a
perl binary for you to make use of, should you not already have a
cygwin compatible one. Note: GHC does <Emphasis>not</Emphasis>
work with the ActiveState port of perl.
</Para>

</Sect3>  <!-- Perl -->

</Sect2>  <!-- Reqd software -->


<Sect2><Title>Installing GHC</Title>

<Para>
Download a GHC distribution:
</Para>

<VariableList>

<VarListEntry>
<Term>ghc-4.045&mdash;InstallShield installer, 10M: <ULink URL="http://www.dcs.gla.ac.uk/~sof/ghc-4.045-win32-IS.zip">http</ULink> or <ULink URL="ftp://ftp.dcs.gla.ac.uk/pub/haskell/glasgow/4.04/ghc-4.045-win32-IS.zip">ftp</ULink>
</Term>

<ListItem>
<Para>
(The version number may change.) It is packaged up using an installer that should be familiar-looking to Windows users. Unpack and double click on <Filename>setup.exe</Filename>.
</Para>

<Para>
Note: The cygwin support for long file names containing
spaces is not 100%, so make sure that you install ghc in a directory
that has no embedded spaces (i.e., resist the temptation to put it
in <Filename>/Program Files/</Filename>!)
</Para>

<Para>
When the installer has completed its job, you may delete the
<Filename>ghcInstall</Filename> directory.
</Para>

<Para>
When the installer has completed, make sure you add the location of the
ghc <Filename>bin/</Filename> directory to your path (i.e. <Filename>/path/to/wherever/ghc-4.05/bin </Filename>).
You need to do this in order to bring the various GHC DLLs into scope;
if not, then you need to copy the DLLs into a directory that is (the
system directory, for example).
</Para>

<Para>
Note: In case you haven't got perl already installed,
you will have to manually copy the <Filename>perl.exe</Filename> binary from the
ghc <Filename>bin/</Filename> into your <Filename>/bin</Filename> directory before continuing&mdash;the installer will not currently do this.
</Para>
</ListItem>

</VarListEntry>

<VarListEntry>
<Term>
ghc-4.045 - gzip'ed tarfile, 7.5M: <ULink URL="http://www.dcs.gla.ac.uk/~sof/ghc-4.045-win32.tar.gz">
http</ULink> or <ULink URL="ftp://ftp.dcs.gla.ac.uk/pub/haskell/glasgow/4.04/ghc-4.045-win32.tar.gz">ftp</ULink>
</Term>

<ListItem>
<Para>
A `normal' GHC binary distribution packaged up as a compressed tar file.
If you're already accustomed to installing and using GHC distributions
on other platforms, the setup should be familiar to you, I
hope. Unpack and read the INSTALL file contained in the
distribution for instructions on how to set it up.
</Para>

<Para>
Notice that the top directory of the distribution contains
(rather clumsily) a perl binary (version 5.005_02). If you
haven't already got a working perl, install this somewhere
along your path too.
</Para>
</ListItem>

</VarListEntry>
</VariableList>

<Para>
Make sure that you set all the environment variables described above
under Cygwin installation, including <Constant>TMPDIR</Constant>
</Para>
<Para>
To test the fruits of your labour, try now to compile a simple
Haskell program:
</Para>

<Screen>
bash$ cat main.hs
module Main(main) where

main = putStrLn "Hello, world!"
bash$ /path/to/the/ghc/bin/directory/ghc-4.05 -o main main.hs
..
bash$ ./main
Hello, world!
bash$ </Screen>

<Para>
OK, assuming that worked, you're all set. Go forth and write useful
Haskell programs :-) If not, consult the installation FAQ (<XRef LinkEnd="winfaq">); if that still doesn't help then please report the problems you're experiencing (see <Xref LinkEnd="wrong">).
</Para>

<Para>
Further information on using GHC under Windows can be found in <ULink URL="http://www.dcs.gla.ac.uk/~sof/ghc-win32.html">Sigbj&oslash;rn Finne's pages</ULink>.
</Para>

</Sect2>

</Sect1>


<Sect1 id="winfaq"><title>Installing ghc-win32 FAQ</title>

<QandASet>

<QandAEntry>

<Question>
<Para>
Invoking ghc doesn't seem to do anything, it immediately returns without having compiled the input file.
</Para>
</Question>

<Answer>
<Para>
One cause of this is that <Filename>/bin/sh</Filename> is missing. To verify, open up a
bash session and type <Command>ls -l /bin/sh.exe</Command>. If <Filename>sh.exe</Filename> is 
reported as not being there, copy <Filename>bash.exe</Filename> (which you'll find
inside the cygwin installation tree as <Filename>H-i586-cygwin32/bin/bash.exe</Filename>)
to <Filename>/bin/sh.exe</Filename>.
</Para>

<Para>
All being well, ghc should then start to function.
</Para>
</Answer>

</QandAEntry>

<QandAEntry>

<Question>
<Para>
When compiling up the <Literal>Hello World</Literal> example, the following happens:
</Para>

<Screen>
bash$ /ghc/ghc-4.05/bin/ghc-4.05 main.hs
&lt;stdin&gt;:0:25: Character literal '{-# LINE 1 "main.hs" -}' too long
&lt;stdin&gt;:0:25:  on input: "'"
bash$ </Screen>

<Para>
or
</Para>

<Screen>
bash$ /ghc/ghc-4.05/bin/ghc-4.05 main.hs
Program too big fit into memory under NT
bash$ </Screen>
</Question>

<Answer>
<Para>
The cause of this is that you're using a version of <Command>perl</Command> that employs the Microsoft <Command>cmd</Command>/<Command>command</Command> shell when launching sub-processes to execute <Function>system()</Function> calls.
</Para>

<Para>
The GHC driver really needs a <Command>perl</Command> which uses a `UNIX'y  shell instead, so
make sure that the version you're using is of an compatible ilk. In particular, 
if <Command>perl -v</Command> reports that you've got a copy of the (otherwise fine) port
of perl done by ActiveState, you're in trouble.
</Para>

<Para>
If you're stuck with an incompatible <Command>perl</Command>, the GHC installation comes with a very basic <Command>perl</Command> binary for you to use. Simply copy it into the <Command>/bin</Command> directory.
</Para>

<Para>
Notice that copying <Filename>perl.exe</Filename> into <Filename>/bin</Filename> will not cause
the GHC install to suddenly start functioning. If you don't want to
re-run the InstallShield installer again, you need to edit the following
files within the directory tree that the installer created:
</Para>

<Screen>
bin/ghc-4.xx   -- where xx is the minor release number
bin/stat2resid
bin/hstags
lib/mkdependHS</Screen>

<Para>
For each of these files, you need to edit the first line from instead
saying <Command>#!/path/to/your/other/perl/install</Command> to <Command>#!/bin/perl</Command>.
Once that is done, try compiling up the Hello, World example again.
</Para>

<Para>
Should you want to pick up a complete installation of a ghc-friendly port
of perl instead, a <ULink URL="http://cygutils.netpedia.net/">cygwin port</ULink> is available.
</Para>
</Answer>

</QandAEntry>

<QAndAEntry>

<Question>
<Para>
<Function>System.getArgs</Function> always return the empty list, i.e. the following program always prints &ldquo;<Literal>[]</Literal>&rdquo;:
</Para>

<ProgramListing>
module Main(main) where
import qualified System
main = System.getArgs >>= print
</ProgramListing>

</Question>

<Answer>
<Para>
This is a bug with the RTS DLL that comes with ghc-4.03. To fix, upgrade to
ghc-4.05.
</Para>
</Answer>

</QAndAEntry>

</QandASet>

</Sect1>


<Sect1>
<Title>Building the documentation</Title>

<Para>
This is a slightly sore point at the moment, because the GHC team has been unable to strike a good balance between having a documentation system that is easy to maintain and one that is widely available. We use the DocBook DTD, which is widely used; however, shrink-wrapped distributions of DocBook are few and far between, and getting it to work out of the box is a nightmare. We settled on the Cygnus DocBook tools; however, these are only available as Red Hat RPMs, and hence at the moment the documentation can only be built on systems which can use RPMs (i.e. most versions of Linux). Sorry about that. We will probably add pre-built documentation to future binary distributions until the situation is sorted out (either we bite the bullet and have our own version of the DocBook tools, or a more portable distribution is made available).
</Para>

<Para>
See the Building Guide for details of what to install to get the DocBook tools and how to build the documentation (it's done by the build system, but just isn't part of a normal build).
</Para>

</Sect1>

</Chapter>