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 variables by setting

them in the environment.  You can do that on the command line like this:

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

   *Note Environment 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 mention 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 host the package

will run on.  Usually `configure' can figure that out, but if it prints

a message saying it cannot guess the host 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 host 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'.  In this case, you should also specify the

build platform with `--build=TYPE', because, in this case, it may not

be possible to guess the build platform (it sometimes involves

compiling and running simple test programs, and this can't be done if

the compiler is a cross compiler).

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.

Environment 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.