如何在特定时间在 Linux 上运行脚本？

我有一个包含特定日期和时间的 < strong > 文本文件。我希望能够 在该文件中指定的时间运行脚本。 你是怎么做到的？创建另一个在后台运行的脚本(类似于守护进程) ，每秒检查当前时间是否与文件中的时间匹配？还有别的办法吗？机器是 Linux服务器 Debian 喘不过气来。先谢谢你

201786 次浏览

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Usually in Linux you use crontab for this kind of scduled tasks. But you have to specify the time when you "setup the timer" - so if you want it to be configurable in the file itself, you will have to create some mechanism to do that.

But in general, you would use for example:

30 1 * * 5 /path/to/script/script.sh

Would execute the script every Friday at 1:30 (AM) Here:

30 is minutes

1 is hour

next 2 *'s are day of month and month (in that order) and 5 is weekday

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The at command exists specifically for this purpose (unlike cron which is intended for scheduling recurring tasks).

at $(cat file) </path/to/script

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最佳答案

Look at the following:

echo "ls -l" | at 07:00

This code line executes "ls -l" at a specific time. This is an example of executing something (a command in my example) at a specific time. "at" is the command you were really looking for. You can read the specifications here:

http://manpages.ubuntu.com/manpages/precise/en/man1/at.1posix.html http://manpages.ubuntu.com/manpages/xenial/man1/at.1posix.html

Hope it helps!

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Cron is good for something that will run periodically, like every Saturday at 4am. There's also anacron, which works around power shutdowns, sleeps, and whatnot. As well as at.

But for a one-off solution, that doesn't require root or anything, you can just use date to compute the seconds-since-epoch of the target time as well as the present time, then use expr to find the difference, and sleep that many seconds.