+sub get_tool_versions ($$)
+{
+ my ($tool_list, $gnulib_version) = @_;
+ @$tool_list
+ or return ();
+
+ my $fail;
+ my @tool_version_pair;
+ foreach my $t (@$tool_list)
+ {
+ if ($t eq 'gnulib')
+ {
+ push @tool_version_pair, ucfirst $t . ' ' . $gnulib_version;
+ next;
+ }
+ # Assume that the last "word" on the first line of
+ # `tool --version` output is the version string.
+ my ($first_line, undef) = split ("\n", `$t --version`);
+ if ($first_line =~ /.* (\d[\w.-]+)$/)
+ {
+ $t = ucfirst $t;
+ push @tool_version_pair, "$t $1";
+ }
+ else
+ {
+ defined $first_line
+ and $first_line = '';
+ warn "$ME: $t: unexpected --version output\n:$first_line";
+ $fail = 1;
+ }
+ }
+
+ $fail
+ and exit 1;
+
+ return @tool_version_pair;
+}
+