README - m4 - Git at Google

 GNU `m4' is an implementation of the traditional Unix macro
 processor.  It is mostly SVR4 compatible, although it has some
 extensions (for example, handling more than 9 positional parameters
 to macros).  `m4' also has built-in functions for including files,
 running shell commands, doing arithmetic, etc.  Autoconf needs GNU
 `m4' for generating `configure' scripts, but not for running them.

 GNU `m4' was originally written by Rene' Seindal, from Denmark.
 This release is considered stable.

 If GNU `m4' is meant to serve GNU `autoconf', beware that `m4'
 should be fully installed *prior to* configuring `autoconf' itself.
 Likewise, if you intend on hacking GNU `m4' from git, the bootstrap
 process requires that you first install a released copy of GNU `m4'.

 If you are just trying to build `m4' from a released tarball, you
 should not normally need to run `./bootstrap' or `autoreconf'; just go
 ahead and start with `./configure'.  If you are trying to build `m4'
 from git, more information can be found in the version-control-only
 file HACKING.

 M4 has an optional dependency on the libsigsegv library:
   http://www.gnu.org/software/libsigsegv/
 If the library has not been installed in the standard location, you
 can use `./configure --with-libsigsegv-prefix=/path/to/dir', to make
 the build of `m4' use /path/to/dir/include/sigsegv.h as appropriate.
 The use of this library is optional; the only difference in having it
 available is that it increases the number of platforms where `m4' can
 correctly distinguish stack overflow from an internal bug.  It is
 recommended that you use version 2.8 or newer.

 In the subdirectory `examples' you will find various m4 files, ranging
 from trivial test files to rather advanced macros.  If you intend to
 use m4 seriously, you might find useful material down there.

 See file `BACKLOG' for a summary of pending mail and articles.
 See file `COPYING' for copying conditions.  Note that M4 is distributed
 under the GNU Public License version 3 or later.  Some files in the
 distribution are copied from the gnulib project, and hence bear the
 designation version 2 or later because they are unmodified from gnulib;
 however, if you modify these files using M4 rather than gnulib as the
 source, you must update the license to be GPLv3 or later.
 See file `INSTALL' for compilation and installation instructions.
 See file `NEWS' for a list of major changes in the current release.
 See file `THANKS' for a list of contributors.

 By default, the `syscmd' and `esyscmd' macros try to use the first
 instance of `sh' found by `command -p getconf PATH' at configure time,
 with a default of `/bin/sh'.  If that default is inappropriate, you
 can use `./configure --with-syscmd-shell=location' to specify the
 shell to use.

 By using `./configure --enable-changeword', you get an experimental
 feature which allows for changing the syntax of what is a "word" in
 `m4'.  This feature will not be present in m4 2.0, but will be
 replaced by other new features which provide similar capability, so
 do not count on it.

 Send bug reports to `bug-m4@gnu.org'.  A bug report is an adequate
 description of the problem: your input, what you expected, what you got,
 and why this is wrong.  Diffs are welcome, but they only describe a
 solution, from which the problem might be uneasy to infer.

 ========================================================================

 Copyright (C) 2000, 2005, 2006, 2007, 2008, 2009, 2010 Free Software
 Foundation, Inc.

 Permission is granted to copy, distribute and/or modify this document
 under the terms of the GNU Free Documentation License, Version 1.3 or
 any later version published by the Free Software Foundation; with no
 Invariant Sections, with no Front-Cover Texts, and with no Back-Cover
 Texts.  A copy of the license is included in the ``GNU Free
 Documentation License'' file as part of this distribution.
	GNU `m4' is an implementation of the traditional Unix macro
	processor. It is mostly SVR4 compatible, although it has some
	extensions (for example, handling more than 9 positional parameters
	to macros). `m4' also has built-in functions for including files,
	running shell commands, doing arithmetic, etc. Autoconf needs GNU
	`m4' for generating `configure' scripts, but not for running them.

	GNU `m4' was originally written by Rene' Seindal, from Denmark.
	This release is considered stable.

	If GNU `m4' is meant to serve GNU `autoconf', beware that `m4'
	should be fully installed prior to configuring `autoconf' itself.
	Likewise, if you intend on hacking GNU `m4' from git, the bootstrap
	process requires that you first install a released copy of GNU `m4'.

	If you are just trying to build `m4' from a released tarball, you
	should not normally need to run `./bootstrap' or `autoreconf'; just go
	ahead and start with `./configure'. If you are trying to build `m4'
	from git, more information can be found in the version-control-only
	file HACKING.

	M4 has an optional dependency on the libsigsegv library:
	http://www.gnu.org/software/libsigsegv/
	If the library has not been installed in the standard location, you
	can use `./configure --with-libsigsegv-prefix=/path/to/dir', to make
	the build of `m4' use /path/to/dir/include/sigsegv.h as appropriate.
	The use of this library is optional; the only difference in having it
	available is that it increases the number of platforms where `m4' can
	correctly distinguish stack overflow from an internal bug. It is
	recommended that you use version 2.8 or newer.

	In the subdirectory `examples' you will find various m4 files, ranging
	from trivial test files to rather advanced macros. If you intend to
	use m4 seriously, you might find useful material down there.

	See file `BACKLOG' for a summary of pending mail and articles.
	See file `COPYING' for copying conditions. Note that M4 is distributed
	under the GNU Public License version 3 or later. Some files in the
	distribution are copied from the gnulib project, and hence bear the
	designation version 2 or later because they are unmodified from gnulib;
	however, if you modify these files using M4 rather than gnulib as the
	source, you must update the license to be GPLv3 or later.
	See file `INSTALL' for compilation and installation instructions.
	See file `NEWS' for a list of major changes in the current release.
	See file `THANKS' for a list of contributors.

	By default, the `syscmd' and `esyscmd' macros try to use the first
	instance of `sh' found by `command -p getconf PATH' at configure time,
	with a default of `/bin/sh'. If that default is inappropriate, you
	can use `./configure --with-syscmd-shell=location' to specify the
	shell to use.

	By using `./configure --enable-changeword', you get an experimental
	feature which allows for changing the syntax of what is a "word" in
	`m4'. This feature will not be present in m4 2.0, but will be
	replaced by other new features which provide similar capability, so
	do not count on it.

	Send bug reports to `bug-m4@gnu.org'. A bug report is an adequate
	description of the problem: your input, what you expected, what you got,
	and why this is wrong. Diffs are welcome, but they only describe a
	solution, from which the problem might be uneasy to infer.

	========================================================================

	Copyright (C) 2000, 2005, 2006, 2007, 2008, 2009, 2010 Free Software
	Foundation, Inc.

	Permission is granted to copy, distribute and/or modify this document
	under the terms of the GNU Free Documentation License, Version 1.3 or
	any later version published by the Free Software Foundation; with no
	Invariant Sections, with no Front-Cover Texts, and with no Back-Cover
	Texts. A copy of the license is included in the ``GNU Free
	Documentation License'' file as part of this distribution.