如何让 bash 脚本循环到特定时间
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How to have a bash script loop until a specific time
提问by user788171
Usually to run an infinite bash loop, I do something like the following:
通常要运行无限 bash 循环，我会执行以下操作：
while true; do
echo test
sleep 1
done
What if instead, I want to do a loop that loops infinitely as long as it is earlier than 20:00. Is there a way to do this in bash?
如果相反，我想做一个无限循环的循环，只要它早于 20:00，该怎么办。有没有办法在 bash 中做到这一点？
回答by fedorqui 'SO stop harming'
You can use dateto print the hours and then compare to the one you are looking for:
您可以使用date打印小时数，然后与您要查找的小时数进行比较：
while [ $(date "+%H") -lt 20 ]; do
echo "test"
sleep 1
done
as date "+%H"shows the current hour, it keeps checking if we are already there or in a "smaller" hour.
如date "+%H"当前小时所示，它会不断检查我们是否已经在那里或在“较小”的小时内。
回答by choroba
Just change trueto the real condition:
只需更改true为实际情况：
while (( $(date +%H) < 20 )) ; do
echo Still not 8pm.
sleep 1
done
回答by mxmlnkn
If you want a specific date, not only full hours, then try comparing the Unix time:
如果您想要一个特定的日期，而不仅仅是完整的小时数，那么请尝试比较 Unix 时间：
while [ $(date +%s) -lt $(date --date="2016-11-04T20:00:00" +%s) ]; do
echo test
sleep 1
done
