“第"当删除失败等错误时退出错误级别设置为 0 [英] "rd" exits with errorlevel set to 0 on error when deletion fails, etc

问题描述

我正在编写一个批处理 (.bat) 脚本，我需要处理文件夹删除失败的情况.我正在使用 %errorlevel% 来捕获退出代码，但在 rd 命令的情况下，它似乎不起作用:

I'm writing a batch (.bat) script and I need to handle the case in which the deletion of a folder fails. I'm using %errorlevel% to catch the exit code, but in the case of the rd command it seems not to work:

C:UsersedoDesktop>rd testdir
Directory is not empty

C:UsersedoDesktop>echo %errorlevel%
0

为什么?你有什么建议?

Why? What do you suggest?

推荐答案

哇，这是我见过的 ERRORLEVEL 设置不正确的第二个案例！请参阅Windows 中的文件重定向和%errorlevel%.

Wow, this is the 2nd case I've seen where ERRORLEVEL is not set properly! See File redirection in Windows and %errorlevel%.

解决方法与检测重定向失败相同.使用 || 操作符在失败时采取行动.

The solution is the same as for detecting redirection failure. Use the || operator to take action upon failure.

rd testdir || echo The command failed!

奇怪的是，当您使用 || 运算符时，如果文件夹不为空，则 ERRORLEVEL 被正确设置为 145，如果文件夹不存在，则设置为 2.所以你甚至不需要做任何事情.您可以有条件地执行"一个注释，然后错误级别将被正确设置.

The bizarre thing is, when you use the || operator, the ERRORLEVEL is then set properly to 145 if the folder was not empty, or 2 if the folder did not exist. So you don't even need to do anything. You could conditionally "execute" a remark, and the errorlevel will then be set properly.

rd testdir || rem
echo %errorlevel%

<小时>

我以为上面给出了一个完整的图片.但是下面的一系列评论表明，在使用 /RD/S 时仍然存在潜在问题.如果父文件夹下的文件或子文件夹被锁定(在父文件夹下的任何级别)，则 RD/S/Q PARENT &&回声已删除 ||echo failed 将打印出错误消息，但是 && 分支会触发，而不是 || 分支.很不幸.如果由于父文件夹本身被锁定而导致命令失败，则 || 将正确触发并设置 ERRORLEVEL.

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I thought the above gave a complete picture. But then a series of comments below demonstrated there are still potential problems when /RD /S is used. If a file or subfolder under the parent folder is locked (at any level under parent) then RD /S /Q PARENT && echo removed || echo failed will print out an error message, but the && branch fires instead of the || branch. Very unfortunate. If the command fails because the parent folder itself is locked, then || will properly fire and set the ERRORLEVEL.

通过将 stderr 与 stdout 交换并将结果传送到 FINDSTR "^"，可以在所有情况下检测失败.如果找到匹配项，则一定有错误.

It is possible to detect failure in all cases by swapping stderr with stdout and piping the result to FINDSTR "^". If a match is found, then there must have been an error.

3>&2 2>&1 1>&3 rd /s test | findstr "^" && echo FAILED

当 /q 缺失时，stderr 和 stdout 的交换很重要，因为它允许你确定(是/否)吗?"提示在 stderr 上可见，与 stdout 上的错误消息分开.

The swap of stderr and stdout is important when /q is missing because it allows the "Are you sure (Y/N)?" prompt to be visible on stderr, separate from the error message on stdout.

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