在Bash中执行时间戳比较的最佳方法是什么？(What is the Best Way to Perform Timestamp Comparison in Bash)

在Bash中执行时间戳比较的最佳方法是什么？(What is the Best Way to Perform Timestamp Comparison in Bash)

我有一个警告脚本，我试图阻止垃圾邮件发送给我，所以我想提出一个条件，如果在最后一小时内发送了警报，不发送另一个警报。 现在我有一个cron工作，每分钟检查一次情况，因为我需要在满足条件时迅速收到警报，但是我不需要每隔一段时间都收到电子邮件，直到问题得到控制。 在bash中比较时间的最佳方法是什么？

I have an alert script that I am trying to keep from spamming me so I'd like to place a condition that if an alert has been sent within, say the last hour, to not send another alert. Now I have a cron job that checks the condition every minute because I need to be alerted quickly when the condition is met but I don't need to get the email every munite until I get the issue under control. What is the best way to compare time in bash to accomplish this?

最满意答案

最简单的方法是将时间戳存储为虚拟文件的修改时间。 GNU touch和date命令可以设置/获取这些时间并执行日期计算。 Bash有测试来检查一个文件是否比（ -nt ）更新或比（ -ot ）更新。

例如，如果最后一次通知超过一小时前才发送通知：

touch -d '-1 hour' limit if [ limit -nt last_notification ]; then #send notification... touch last_notification fi

By far the easiest is to store time stamps as modification times of dummy files. GNU touch and date commands can set/get these times and perform date calculations. Bash has tests to check whether a file is newer than (-nt) or older than (-ot) another.

For example, to only send a notification if the last notification was more than an hour ago:

touch -d '-1 hour' limit if [ limit -nt last_notification ]; then #send notification... touch last_notification fi