dnl CF_LEX_VERSION version: 6 updated: 2020/12/31 20:19:42
dnl --------------
dnl Check if "lex" is really "flex", and if so, set $LEX_VERSION to show its
dnl version.
AC_DEFUN([CF_LEX_VERSION],[
AC_REQUIRE([AC_PROG_LEX])

test -z "$LEX" && LEX="lex"
test "x$LEX" = "x:" && LEX="lex"  # : is not a usable default
AC_MSG_CHECKING(if $LEX is really flex)
if ( $LEX '-?' </dev/null 2>&1 |fgrep flex >/dev/null )
then
	AC_MSG_RESULT(yes)
	AC_MSG_CHECKING(version of $LEX)
	LEX_VERSION="`$LEX --version </dev/null 2>&1 | sed -e 's/^.* \([[0-9]]\)/\1/;s/ .*$//;s/^[[^0-9]]*//'`"
	AC_MSG_RESULT($LEX_VERSION)
else
	AC_MSG_RESULT(no)
fi

])dnl
