- *)
- echo 1>&2 "\
-WARNING: \`$1' is needed, and you do not seem to have it handy on your
- system. You might have modified some files without having the
- proper tools for further handling them. Check the \`README' file,
- it often tells you about the needed prerequirements for installing
- this package. You may also peek at any GNU archive site, in case
- some other package would contain this missing \`$1' program."
- exit 1
+perl_URL=http://www.perl.org/
+flex_URL=http://flex.sourceforge.net/
+gnu_software_URL=http://www.gnu.org/software
+
+program_details ()
+{
+ case $1 in
+ aclocal|automake)
+ echo "The '$1' program is part of the GNU Automake package:"
+ echo "<$gnu_software_URL/automake>"
+ echo "It also requires GNU Autoconf, GNU m4 and Perl in order to run:"
+ echo "<$gnu_software_URL/autoconf>"
+ echo "<$gnu_software_URL/m4/>"
+ echo "<$perl_URL>"
+ ;;
+ autoconf|autom4te|autoheader)
+ echo "The '$1' program is part of the GNU Autoconf package:"
+ echo "<$gnu_software_URL/autoconf/>"
+ echo "It also requires GNU m4 and Perl in order to run:"
+ echo "<$gnu_software_URL/m4/>"
+ echo "<$perl_URL>"
+ ;;
+ esac
+}
+
+give_advice ()
+{
+ # Normalize program name to check for.
+ normalized_program=`echo "$1" | sed '
+ s/^gnu-//; t
+ s/^gnu//; t
+ s/^g//; t'`
+
+ printf '%s\n' "'$1' is $msg."
+
+ configure_deps="'configure.ac' or m4 files included by 'configure.ac'"
+ case $normalized_program in
+ autoconf*)
+ echo "You should only need it if you modified 'configure.ac',"
+ echo "or m4 files included by it."
+ program_details 'autoconf'
+ ;;
+ autoheader*)
+ echo "You should only need it if you modified 'acconfig.h' or"
+ echo "$configure_deps."
+ program_details 'autoheader'
+ ;;
+ automake*)
+ echo "You should only need it if you modified 'Makefile.am' or"
+ echo "$configure_deps."
+ program_details 'automake'
+ ;;
+ aclocal*)
+ echo "You should only need it if you modified 'acinclude.m4' or"
+ echo "$configure_deps."
+ program_details 'aclocal'
+ ;;
+ autom4te*)
+ echo "You might have modified some maintainer files that require"
+ echo "the 'autom4te' program to be rebuilt."
+ program_details 'autom4te'
+ ;;
+ bison*|yacc*)
+ echo "You should only need it if you modified a '.y' file."
+ echo "You may want to install the GNU Bison package:"
+ echo "<$gnu_software_URL/bison/>"
+ ;;
+ lex*|flex*)
+ echo "You should only need it if you modified a '.l' file."
+ echo "You may want to install the Fast Lexical Analyzer package:"
+ echo "<$flex_URL>"
+ ;;
+ help2man*)
+ echo "You should only need it if you modified a dependency" \
+ "of a man page."
+ echo "You may want to install the GNU Help2man package:"
+ echo "<$gnu_software_URL/help2man/>"