Copyright (C)  2005, 2006, 2007, 2008, 2009, 2010, 2011, 2012, 2013, 2014, 2015, 2016, 2017  Ivano Primi  <ivprimi@libero.it>    

   Copying and distribution of this file, with or without modification,
   are permitted in any medium without royalty provided the copyright
   notice and this notice are preserved.

***********************************************************************************

How to build and install Numdiff
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

To successfully compile, build and install Numdiff some
tools are required. The first one is an ANSI C compiler.
This compiler should at least accept the option `-o'
to write its output to a specified file,
the option `-D' for macros pre-definition,
the option `-l' to search for a specified library,
and the options `-I' and `-L'
to add a given directory to the search path for include and
library files respectively.

In addition, you need a POSIX implementation of the `make' utility
(I used both GNU make and smake by Joerg Schilling 
to compile Numdiff) and a POSIX implementation
of the commands `rm' and `find'.
At last, you need a proper installation of GNU Texinfo 
(in order to install the info documentation) and
a shell sh-compatible.

Numdiff has been successfully compiled and tested on:

 - Slackware(R) GNU/Linux 10.2 with the version 3.3.6 of the GNU C Compiler (GCC),
 - Slackware GNU/Linux 11 with GCC 3.4.6,
 - Slackware GNU/Linux 12.2 with GCC 4.2.4, 
 - Slackware GNU/Linux 13 with GCC 4.3.3, 
 - Debian(R) GNU/Linux 4.0 with GCC 4.1.2 20061115 (prerelease) (Debian 4.1.1-21),
 - Debian GNU/Linux 6.0.3 with GCC 4.4.5 (Debian 4.4.5-8),
 - Debian GNU/Linux 7.1 with GCC 4.7.2 (Debian 4.7.2-5),
 - Debian GNU/Linux 8.6 with GCC 4.9.2 (Debian 4.9.2-10), 
 - SunOS(R) 5.8 with GCC 2.95.3, and 
 - SunOS 5.10 (i386) with the version 5.9 of the Sun C compiler.

Configuration, building and installation of Numdiff can be
performed through the standard three steps:

        ./configure
        make
        make install

If you leave enabled the Natural Language Support and you
also want to install the localization files (at the moment
only the Italian localization is supplied), then after
`make' you will have to type and run

        make install-nls

By default, `make install' will install all the files in
`/usr/local/bin', `/usr/local/info' etc.  You can specify
an installation prefix other than `/usr/local' using the
option `--prefix' in the `configure' step,
for instance `--prefix=$HOME':

        ./configure --prefix=$HOME

For better control, you can use the options
`--bindir', `--infodir', and so on. 
Type `./configure --help' to obtain
the complete list of all available options.

The documentation files (including a full User Manual
available in HTML, PDF and plain ASCII text format)
will always be put in `DOCDIR/numdiff',
where `DOCDIR' is the path specified by the option `--docdir'
or, if this option has not been given to
`configure', `PREFIX/share/doc'. Here `PREFIX' is the
installation prefix specified by the
option `--prefix' or the default `/usr/local'.

Once Numdiff has been installed you can remove all
files related to Numdiff by a simple `make uninstall'.
If you have also installed the localization files trough
`make install-nls', use `make uninstall-nls' in place
of `make uninstall' to remove them too.

Between the options accepted by `configure'
there are `--enable-debug', `--enable-optimization',
`--enable-nls' and `--enable-gmp'.

The option `--enable-debug' turns on debugging when
compiling the source code. This is obtained by passing to the
compiler the `-g' option, but you can change this default
debugging flag (which could not even be recognized by your compiler)
by setting the environment variable `DBGFLAGS' before
calling `configure'.

The option `--enable-optimization' turns on basic optimization when
compiling the source code. This is obtained by passing to the
compiler the `-O' option, but you can change this default
flag (which could not even be recognized by your compiler)
by setting the environment variable `OPTFLAGS' before
calling `configure'.

The option `--enable-nls' turns on Natural Language Support.
You do not need to use it explicitly since Natural
Language Support is enabled by default. To disable it, use `--disable-nls'.
Disabling Natural Language Support is suggested whenever
you want to install Numdiff on a system where the GNU gettext library
is not present. In this case the installation of Numdiff 
can be accomplished, for example, through

        ./configure --disable-nls
        make
        make install

Since version 5.2.0 Numdiff uses to perform all computations
the GNU Multiple Precision Arithmetic Library
(also called GNU MP or GMP), if this library is available 
at build-time.
The old internal support for multiple precision arithmetic
is a fall-back in case GNU MP is absent.
However, it is possible to use the internal support for 
multiple precision arithmetic even when GNU MP is available:
it is sufficient to pass the option `--enable-gmp=no'
or `--disable-gmp' to the  configure  script
before building the program, like in

        ./configure --disable-gmp
        make
        make install

Enabling the old internal support for multiple precision arithmetic
is deprecated, I suggest to always link Numdiff against GNU MP.
The latest version of GNU MP is available at
http://ftp.gnu.org/gnu/gmp/. See the GNU MP web page
at  http://gmplib.org/  for up-to-date information on GNU MP.

Below, I have attached the generic INSTALL instructions included in the
autoconf distribution.
----------------------------------------------------------------------------

Copyright (C) 1994, 1995, 1996, 1999, 2000, 2001, 2002 Free Software
Foundation, Inc.

   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 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 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.