Remove warnings and bump autoconf version to 2.69

Author: eribertomota

configure.ac

@@ -1,17 +1,14 @@
-#                                               -*- Autoconf -*-
-# Process this file with autoconf to produce a configure script.
-#
 # Copyright 2005-2008 David Snyder <dasnyderx(at)yahoo(dot)com>
 # Copyright 2019-2021 Joao Eriberto Mota Filho <eriberto@eriberto.pro.br>
 #
 # This file is under the same terms described by
 # LICENSE file for the main source code (rdate.c).
 
-AC_PREREQ(2.61)
+AC_PREREQ([2.69])
 AC_INIT([openrdate],[1.10.1],[https://github.com/resurrecting-open-source-projects/openrdate/issues])
 AM_INIT_AUTOMAKE
 AC_CONFIG_SRCDIR([src/rdate.c])
-AC_CONFIG_HEADER([config.h])
+AC_CONFIG_HEADERS([config.h])
 AC_ARG_VAR([kernel_version], [the version of the kernel to build against])
 
 # Checks for programs.
@@ -23,14 +20,14 @@ fi
 
 AC_PROG_INSTALL
 AC_PROG_RANLIB
+AC_PROG_EGREP
 
 # Checks for libraries.
 AC_CHECK_LIB([c], [fork])
 AC_CHECK_LIB([util], [malloc])
 
 #
 # Checks for header files.
-AC_HEADER_STDC
 AC_CHECK_HEADERS([arpa/inet.h fcntl.h float.h limits.h netdb.h \
                   netinet/in.h stdlib.h string.h sys/param.h sys/socket.h \
                   sys/time.h unistd.h util.h])
@@ -43,7 +40,6 @@ AC_C_INLINE
 AC_TYPE_OFF_T
 AC_TYPE_PID_T
 AC_TYPE_SIZE_T
-AC_HEADER_TIME
 AC_STRUCT_TM
 
 # Checks for library functions.
@@ -53,7 +49,7 @@ AC_FUNC_STRFTIME
 AC_CHECK_FUNCS([gettimeofday memset select socket])
 
 # Check for uname prog
-AC_PATH_PROG([UNAME], [uname], 
+AC_PATH_PROG([UNAME], [uname],
                [:])
 
 AC_CANONICAL_HOST
@@ -66,10 +62,10 @@ case "${host}" in
         if test "x${kernel_version}" = "x" && test "x${UNAME}" != "x:" ; then
             UNAMEOUT=`nice ${UNAME} -r 2> /dev/null`
             if test "x${UNAMEOUT}" != "x"; then
-                NO_SYSCTL=`echo ${UNAMEOUT} | ${AWK} -F '.' '{ if ($1 >= 2 && 
-                                                            $2 >= 6 && 
-                                                            $3 >= 19) 
-                                                                print "1"; 
+                NO_SYSCTL=`echo ${UNAMEOUT} | ${AWK} -F '.' '{ if ($1 >= 2 &&
+                                                            $2 >= 6 &&
+                                                            $3 >= 19)
+                                                                print "1";
                                                             else print "0"; }'`
                 if test "x${NO_SYSCTL}" = "x1"; then
                     AC_DEFINE([__NO_SYSCTL__], [1], [Do not use the sysctl calls.])