+dnl ** check for POSIX regex
+HavePosixRegex=NO
+AC_CHECK_HEADERS([regex.h], [AC_CHECK_FUNCS(regcomp, [HavePosixRegex=YES])])
+AC_SUBST(HavePosixRegex)
+
+dnl ** check for wide-char classifications
+dnl FreeBSD has an emtpy wctype.h, so test one of the affected
+dnl functions if it's really there.
+AC_CHECK_HEADERS([wctype.h], [AC_CHECK_FUNCS(iswspace)])
+
+AC_CHECK_FUNCS([ftime gmtime_r localtime_r lstat readdir_r])
+
+AC_CHECK_FUNCS([_chsize ftruncate])
+