我在 bash 配置文件中使用一个at命令来每小时回显一天中的时间来提醒我时间，但现在当我打开命令行时，它会闪烁很多恼人的警告，如下所示：
warning: commands will be executed using /bin/sh
job 241 at Thu Sep 1 00:00:00 2016
warning: commands will be executed using /bin/sh
job 242 at Thu Sep 1 01:00:00 2016
warning: commands will be executed using /bin/sh
job 243 at Thu Sep 1 02:00:00 2016
warning: commands will be executed using /bin/sh
job 244 at Thu Sep 1 03:00:00 2016
warning: commands will be executed using /bin/sh
job 245 at Thu Sep 1 04:00:00 2016
warning: commands will be executed using /bin/sh
job 246 at Thu Sep 1 05:00:00 2016
warning: commands will be executed using /bin/sh
job 247 at Thu Sep 1 06:00:00 2016
warning: commands will be executed using /bin/sh
job 248 at Thu Sep 1 07:00:00 2016
warning: commands will be executed using /bin/sh
job 249 at Thu Sep 1 08:00:00 2016
warning: commands will be executed using /bin/sh
job 250 at Thu Sep 1 09:00:00 2016
warning: commands will be executed using /bin/sh
job 251 at Wed Aug 31 10:00:00 2016
warning: commands will be executed using /bin/sh
job 252 at Wed Aug 31 11:00:00 2016
warning: commands will be executed using /bin/sh
job 253 at Wed Aug 31 12:00:00 2016
warning: commands will be executed using /bin/sh
job 254 at Wed Aug 31 13:00:00 2016
warning: commands will be executed using /bin/sh
job 255 at Wed Aug 31 14:00:00 2016
warning: commands will be executed using /bin/sh
job 256 at Wed Aug 31 15:00:00 2016
warning: commands will be executed using /bin/sh
job 257 at Wed Aug 31 16:00:00 2016
warning: commands will be executed using /bin/sh
job 258 at Wed Aug 31 17:00:00 2016
warning: commands will be executed using /bin/sh
job 259 at Wed Aug 31 18:00:00 2016
warning: commands will be executed using /bin/sh
job 260 at Wed Aug 31 19:00:00 2016
warning: commands will be executed using /bin/sh
job 261 at Wed Aug 31 20:00:00 2016
warning: commands will be executed using /bin/sh
job 262 at Wed Aug 31 21:00:00 2016
warning: commands will be executed using /bin/sh
job 263 at Wed Aug 31 22:00:00 2016
warning: commands will be executed using /bin/sh
job 264 at Wed Aug 31 23:00:00 2016
我尝试运行的命令是示例：
echo "midnight" | at 00:00
我怎样才能删除这些警告？
注意：这不像问题； “为什么at警告我将使用 /bin/sh 执行命令？如果我想要不同的 shell 怎么办？”因为，我不想知道为什么我想知道如何摆脱警告，并且我不想知道有关 shell 的任何信息。
答案1
echo "midnight" | at 00:00 2>/dev/null