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 builtin 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' has been originally written by René Seindal, from Denmark.
GNU `m4' has a web site at http://www.seindal.dk/rene/gnu/.
If GNU `m4' is meant to serve GNU `autoconf', beware that `m4'
should be fully installed *prior to* configuring `autoconf' itself.
In the subdirectories `tests' and `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
See file `COPYING' for copying conditions.
See file `INSTALL' for compilation and installation instructions.
See file `ABOUT-NLS' for how to customize this program to your language.
See file `NEWS' for a list of major changes in the current release.
See file `AUTHORS' for the names of maintainers.
See file `THANKS' for a list of contributors.
By using `./configure --with-gmp, you get multiple precision integral
and rational arithmetic using mpeval. The implementation depends on the
GNU gmp v2 library.
By using `./configure --with-modules=`foo bar baz', you get an m4 with only
the named modules preloaded. The default modules (preloaded if you do not
use this option) are sufficient to do the job of GNU m4-1.4. Additional
modules may be desirable, or necessary if libltdl does not support your
host architecture. The implementation uses libltdl interface, details of
which are in the libtool manual. See file `modules/README' for a more
By using `./configure --enable-changeword', you get an m4 with a
significantly slower parser, but with support for an experimental
feature which allows for changing the syntax of what is a "word" in
`m4'. An m4 built this way provides the `--word-regexp' (-W) option,
and a working `changeword' macro if you also load the `changeword'
module. THIS WILL PROBABLY GO AWAY, so don't count on it. Some of the
same things can be achieved with `changesyntax' at a much better speed.
By using `./configure --with-dmalloc', GNU m4 is linked with Gray
Watson's dmalloc package. It is a debugging option for finding memory
management problems. Gray Watson's dmalloc package is available at
When compiling on cygwin (b20.1 at least), the cygwin getopt build
doesn't handle optional arguments properly. The best way to get around
this is to force the build to use the included getopt files like this,
The Windows dll mechanism conflicts with the requirements of NLS, so
you should use `./configure --disable-nls' on these machines. The problem
is that an internationalised libm4.dll requires libintl.a to resolve its
unbound symbols at compile time. On real operating systems, linking
libintl.a into the m4 binary and using -export-dynamic is good enough.
Send bug reports, comments or ideas to `firstname.lastname@example.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. Don't forget all relevant information about your operating
system, compiler, libraries, ...