Input 超时用户输入csh shell

是否有可能使c shell的用户输入超时？到目前为止，我的代码是：

    #!/bin/csh -f 


    set COUNT = 5
    printf "INFO: Start ok (0/1)? "
    set INPUT = 0

    while ($COUNT > 0 && $INPUT == 0)
      printf "\b%d" "$COUNT"
      set INPUT = <$
      sleep 1
      @ COUNT --
    end

    if ($INPUT == 1) then
    ./execute.sh
    end

#/垃圾箱/垃圾箱-f
设置计数=5
printf“信息：开始正常（0/1）？”
设置输入=0
而（$COUNT>0&&$INPUT==0）
printf“\b%d”“$COUNT”
set INPUT=在tcsh shell中为非阻塞用户输入尝试以下操作：

set TMPFILE = `mktemp`
set COUNT = 5
printf "INFO: Start ok (0/1)? "
stty -F /dev/tty -icanon
while ($COUNT > 0 && -z $TMPFILE)
  printf "\b%d" "$COUNT"
  sleep 1
  (dd bs=1 count=1 iflag=nonblock > $TMPFILE) >& /dev/null
  set INPUT = `cat $TMPFILE`
  @ COUNT--
end
stty -F /dev/tty icanon
echo ""
if ("$INPUT" == "1") then
  ./execute.sh
endif