    MODULE=m4
   VERSION=1.4.21
    SOURCE=$MODULE-$VERSION.tar.bz2
SOURCE_URL=$GNU_URL/$MODULE
SOURCE_VFY=sha256:dc487e11d2f0c9e01555bb1af26be4eae983ec8f0726746505b4327186eb21fc
  WEB_SITE=https://www.gnu.org/software/m4/
   ENTERED=20010922
   UPDATED=20260609
     SHORT="GNU m4 macro processor"

cat << EOF
GNU m4 is an implementation of the traditional UNIX macro processor in
that it copies its input to the output, expanding macros as it goes.
Macros are either built-in or user-defined and can take any number of
arguments. M4 also has built-in functions for including named files,
running UNIX commands, doing integer arithmetic, manipulating text in
various ways, and recursions.
It can also be used as either a front-end to a compiler or as a macro
processor in its own right. It is often used to generate HTML as it can
give a consistent look to pages. If GNU m4 is meant to serve GNU
autoconf, beware that m4 should be fully installed *prior to*
configuring autoconf itself.
EOF
