正确地为批处理脚本创建的日志文件添加时间戳 [英] Properly timestamp a log file created by batch script

问题描述

我正在尝试使用在批处理文件中发生的事件的时间戳创建日志文件.

I am trying to create a log file with timestamps of events that are taking place in a batch file.

从下面的代码中可以看到，在编写批处理文件时，我不是专家.尽管该技术非常差，但该过程仍应按预期进行.为了防止批处理文件被删除，我将其设置为只读.我将设法弄清楚如何在某些时候排除批处理文件.现在那还不那么重要.

As you can see from the code below, I am not an expert when it comes to writing a batch file. The process works as it should, although the technique is very poor. In order to keep the batch file from deleting itself, I set it to read-only. I'll get around to figuring out how to exclude the batch file at some point. Right now that isn't as important.

@echo off
echo Compressing Files...
echo Compression Batch File STARTED: %date% %time% >> c:\temp\backup-compress.log
echo --------------------------------------------- >> c:\temp\backup-compress.log
for %%X in (*) do ( 
    "c:\Program Files\7-Zip\7z.exe" a -tgzip "%%X.gz" "%%X"
    echo %%X Compressed: %date% %time:~-11,8% >> c:\temp\backup-compress.log
    echo Deleting: %%X
    del "%%X"
    echo %%X Deleted: %date% %time:~-11,8% >> c:\temp\backup-compress.log
    )
echo Moving compressed copies to Compressed Backups folder...
move *.gz "Compressed Backups\" > NUL
echo --------------------------------------------- >> c:\temp\backup-compress.log
echo Compression Batch File FINSHED: %date% %time% >> c:\temp\backup-compress.log
echo Compression completed successfully...
echo

生成的日志文件完全符合我的期望，但是，时间戳记和日期在整个日志中保持不变.我不会看到批处理文件中发生事件时的更新时间戳，而只能看到启动批处理文件的时间和日期，而不是每个％time％和％date％实例.

The resulting log file looks exactly how I want it to, however, the time stamp and date remain constant throughout the log. Rather than an updated time stamp as events occur in the batch file, I only see the time and date that the batch file was started in place of every %time% and %date% instance.

如何解决此问题，并为正在创建的日志文件查看正确的时间和日期戳?

PS:请原谅我的这篇文章的篇幅以及可能要解决的简单问题.另外，如果标签不太正确，对不起，这是我第一次实际发布问题，尽管该网站一直以来都是解答问题的理想资源.

PS: Forgive me for the length of this post and what is likely a simple problem to solve. Also, if the tags are not quite right, I apologize, this is my first time actually posting a question, although the site has always been a great resource for answers.

推荐答案

这是因为cmd在不是直接在执行之前进行解析的语句时会扩展变量.在这种情况下，语句是完整的for，包括其后的块.因此，for循环中保留的只是文字字符串，没有变量.

This is because cmd expands variables when a statement is parsed not directly prior to execution. A statement in this case is the complete for including the block after it. So all that remains within the for loop are literal strings, no variables.

您可以使用延迟扩展来更正此问题.在批处理的开始处放置以下内容:

You can use delayed expansion to correct the issue. Put the following at the start of your batch:

setlocal enabledelayedexpansion

，然后在循环中使用!date!和!time!.这样将在执行语句之前扩展变量，从而可以按预期工作.

and then use !date! and !time! within the loop. This will expand the variables just prior to executing a statement and thus will work as intended.

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