INSTALL

This file is free documentation; the Free Software Foundation gives unlimited permission
to copy, distribute and modify it.

Basic Installation
==================

These are generic installation instructions.

The `configure' shell script attempts to guess correct values for various system-dependent
variables used during compilation.  It uses those values to create a `Makefile' in each
directory of the package.  It may also create one or more `.h' files containing
system-dependent definitions.  Finally, it creates a shell script `config.status' that you
can run in the future to recreate the current configuration, and a file `config.log'
containing compiler output (useful mainly for debugging `configure').

It can also use an optional file (typically called `config.cache' and enabled with
`--cache-file=config.cache' or simply `-C') that saves the results of its tests to speed
up reconfiguring.  (Caching is disabled by default to prevent problems with accidental use
of stale cache files.)

If you need to do unusual things to compile the package, please try to figure out how
`configure' could check whether to do them, and mail diffs or instructions to the address
given in the `README' so they can be considered for the next release.  If you are using
the cache, and at some point `config.cache' contains results you don't want to keep, you
may remove or edit it.

The file `configure.ac' (or `configure.in') is used to create `configure' by a program
called `autoconf'.  You only need `configure.ac' if you want to change it or regenerate
`configure' using a newer version of `autoconf'.

The simplest way to compile this package is:

  1. `cd' to the directory containing the package's source code and type `./configure' to
     configure the package for your system.  If you're using `csh' on an old version of
     System V, you might need to type `sh ./configure' instead to prevent `csh' from
     trying to execute `configure' itself.

     Running `configure' takes awhile.  While running, it prints some messages telling
     which features it is checking for.

  2. Type `make' to compile the package.

  3. Optionally, type `make check' to run any self-tests that come with the package.

  4. Type `make install' to install the programs and any data files and documentation.

  5. You can remove the program binaries and object files from the source code directory
     by typing `make clean'.  To also remove the files that `configure' created (so you
     can compile the package for a different kind of computer), type `make distclean'.
     There is also a `make maintainer-clean' target, but that is intended mainly for the
     package's developers.  If you use it, you may have to get all sorts of other programs
     in order to regenerate files that came with the distribution.

Compilers and Options
=====================

Some systems require unusual options for compilation or linking that the `configure'
script does not know about.  Run `./configure --help' for details on some of the pertinent
environment variables.

You can give `configure' initial values for configuration parameters by setting variables
in the command line or in the environment.  Here is an example:

     ./configure CC=c89 CFLAGS=-O2 LIBS=-lposix

   *Note Defining Variables::, for more details.

Compiling For Multiple Architectures
====================================

You can compile the package for more than one kind of computer at the same time, by
placing the object files for each architecture in their own directory.  To do this, you
must use a version of `make' that supports the `VPATH' variable, such as GNU `make'.  `cd'
to the directory where you want the object files and executables to go and run the
`configure' script.  `configure' automatically checks for the source code in the directory
that `configure' is in and in `..'.

If you have to use a `make' that does not support the `VPATH' variable, you have to
compile the package for one architecture at a time in the source code directory.  After
you have installed the package for one architecture, use `make distclean' before
reconfiguring for another architecture.

Installation Names
==================

By default, `make install' will install the package's files in `/usr/local/bin',
`/usr/local/man', etc.  You can specify an installation prefix other than `/usr/local' by
giving `configure' the option `--prefix=PATH'.

You can specify separate installation prefixes for architecture-specific files and
architecture-independent files.  If you give `configure' the option `--exec-prefix=PATH',
the package will use PATH as the prefix for installing programs and libraries.
Documentation and other data files will still use the regular prefix.

In addition, if you use an unusual directory layout you can give options like
`--bindir=PATH' to specify different values for particular kinds of files.  Run `configure
--help' for a list of the directories you can set and what kinds of files go in them.

If the package supports it, you can cause programs to be installed with an extra prefix or
suffix on their names by giving `configure' the option `--program-prefix=PREFIX' or
`--program-suffix=SUFFIX'.

Optional Features
=================

Some packages pay attention to `--enable-FEATURE' options to `configure', where FEATURE
indicates an optional part of the package.  They may also pay attention to
`--with-PACKAGE' options, where PACKAGE is something like `gnu-as' or `x' (for the X
Window System).  The `README' should mentiopn any `--enable-' and `--with-' options that
the package recognizes.

For packages that use the X Window System, `configure' can usually find the X include and
library files automatically, but if it doesn't, you can use the `configure' options
`--x-includes=DIR' and `--x-libraries=DIR' to specify their locations.

Specifying the System Type
==========================

There may be some features `configure' cannot figure out automatically, but needs to
determine by the type of machine the package will run on.  Usually, assuming the package
is built to be run on the _same_ architectures, `configure' can figure that out, but if it
prints a message saying it cannot guess the machine type, give it the `--build=TYPE'
option.  TYPE can either be a short name for the system type, such as `sun4', or a
canonical name which has the form:

     CPU-COMPANY-SYSTEM

where SYSTEM can have one of these forms:

     OS KERNEL-OS

See the file `config.sub' for the possible values of each field.  If `config.sub' isn't
included in this package, then this package doesn't need to know the machine type.

If you are _building_ compiler tools for cross-compiling, you should use the
`--target=TYPE' option to select the type of system they will produce code for.

If you want to _use_ a cross compiler, that generates code for a platform different from
the build platform, you should specify the "host" platform (i.e., that on which the
generated programs will eventually be run) with `--host=TYPE'.

Sharing Defaults
================

If you want to set default values for `configure' scripts to share, you can create a site
shell script called `config.site' that gives default values for variables like `CC',
`cache_file', and `prefix'.  `configure' looks for `PREFIX/share/config.site' if it
exists, then `PREFIX/etc/config.site' if it exists.  Or, you can set the `CONFIG_SITE'
environment variable to the location of the site script.  A warning: not all `configure'
scripts look for a site script.

Defining Variables
==================

Variables not defined in a site shell script can be set in the environment passed to
`configure'.  However, some packages may run configure again during the build, and the
customized values of these variables may be lost.  In order to avoid this problem, you
should set them in the `configure' command line, using `VAR=value'.  For example:

     ./configure CC=/usr/local2/bin/gcc

will cause the specified gcc to be used as the C compiler (unless it is overridden in the
site shell script).

`configure' Invocation
======================

`configure' recognizes the following options to control how it operates.

`--help'
`-h'
     Print a summary of the options to `configure', and exit.

`--version'
`-V'
     Print the version of Autoconf used to generate the `configure' script, and exit.

`--cache-file=FILE'
     Enable the cache: use and save the results of the tests in FILE, traditionally
     `config.cache'.  FILE defaults to `/dev/null' to disable caching.

`--config-cache'
`-C'
     Alias for `--cache-file=config.cache'.

`--quiet'
`--silent'
`-q'
     Do not print messages saying which checks are being made.  To suppress all normal
     output, redirect it to `/dev/null' (any error messages will still be shown).

`--srcdir=DIR'
     Look for the package's source code in directory DIR.  Usually `configure' can
     determine that directory automatically.

`configure' also accepts some other, not widely useful, options.  Run
`configure --help' for more details.