批处理文件和 DEL 错误级别 0 问题 [英] Batch file and DEL errorlevel 0 issue

问题描述

批处理必须从特定位置删除文件和目录，并将成功或 stdout/stderr 消息输出到新的 .txt 文件.我已经创建了脚本的大部分内容，它完全按照预期执行，除非删除成功后它会前进到下一行，而不是在日志上回显成功"消息.

The batch has to remove files and directories from specific locations and output success or stdout/stderr messages to a new .txt file. I have created the most of the script and it performs exactly as it should, except when the deletion is successful it moves forward to the next line rather than echo a 'successful' message on the log.

echo Basic Deletion Batch Script > results.txt
@echo off
call :filelog >> results.txt 2>&1
notepad results.txt
exit /b

:filelog

call :delete new.txt
call :delete newer.txt
call :delete newest.txt
call :remove c:NoSuchDirectory

GOTO :EOF

:delete
echo deleting %1
del /f /q c:Users
ewuserDesktop\%1 
if errorlevel 0 echo succesful

GOTO :EOF

:remove
echo deleting directory %1
rmdir /q /s %1

GOTO :EOF

出于某种原因，我找不到 if del successes echo 'successful' 的语法.在上面的例子中，如果我删除了

For some reason I can't find the syntax for if del succeeds echo 'successful'. In the above example if I remove the line

if errorlevel 0 echo successful

一切正常，但没有成功消息.留下这条线，它对每一行都表示成功.

Everything works fine, but no success message. With this line left in it echoes success for every line.

推荐答案

del 和 ErrorLevel?

del 命令不会设置 ErrorLevel 只要给定的参数有效，它甚至会将 ErrorLevel 重置为 0 在这种情况下(至少对于 Windows 7).

del and ErrorLevel?

The del command does not set the ErrorLevel as long as the given arguments are valid, it even resets the ErrorLevel to 0 in such cases (at least for Windows 7).

del 仅在提供无效开关的情况下修改 ErrorLevel(del/X 将 ErrorLevel 设置为1)，根本没有指定任何参数(del 也将 ErrorLevel 设置为 1)，或者文件不正确给出路径(del : 将 ErrorLevel 设置为 123)，至少对于 Windows 7.

del modifies the ErrorLevel only in case an invalid switch is provided (del /X sets ErrorLevel to 1), no arguments are specified at all (del sets ErrorLevel to 1 too), or an incorrect file path is given (del : sets ErrorLevel to 123), at least for Windows 7.

一种可能的解决方法是捕获 del 的 STDERR 输出，因为如果出现删除错误，相关消息(Could Not Find [...], 访问被拒绝., 进程无法访问该文件，因为它正被另一个进程使用.) 写在那里.这可能看起来像:

A possible work-around is to capture the STDERR output of del, because in case of deletion errors, the related messages (Could Not Find [...], Access is denied., The process cannot access the file because it is being used by another process.) are written there. Such might look like:

for /F "tokens=*" %%# in ('del /F /Q "path	o	hefile_s.txt" 2^>^&1 1^> nul') do (2> nul set =)

要直接在命令提示符中而不是在批处理文件中使用代码，请编写 %# 而不是 %%#.

To use the code in command prompt directly rather than in a batch file, write %# instead of %%#.

如果不想删除只读文件，请从del命令行中删除/F；
如果您确实需要提示(如果文件路径中存在通配符 ? 和/或 *)，请删除 /Q.

If you do not want to delete read-only files, remove /F from the del command line;
if you do want prompts (in case wildcards ? and/or * are present in the file path), remove /Q.

这将执行命令行del/F/Qpath o hefile_s.txt".由部分 2>&1 1>nul，STDOUT 处的命令输出将被解除，其 STDERR 输出将被重定向，以便 for/F 接收它.

This executes the command line del /F /Q "path o hefile_s.txt". By the part 2>&1 1> nul, the command output at STDOUT will be dismissed, and its STDERR output will be redirected so that for /F receives it.

如果删除成功，del 不会生成 STDERR 输出，因此 for/F 循环不会迭代，因为有没什么好解析的.注意 ErrorLevel 在这种情况下不会被重置，它的值保持不变.

If the deletion was successful, del does not generate a STDERR output, hence the for /F loop does not iterate, because there is nothing to parse. Notice that ErrorLevel will not be reset in that case, its value remains unchanged.

如果 for/F 从 del 命令行收到任何 STDERR 输出，则执行循环体中的命令，即 <代码>设置=;这是无效的语法，因此 set 将 ErrorLevel 设置为 1.<代码>2>null 部分避免了消息命令的语法不正确.被显示.

If for /F recieves any STDERR output from the del command line, the command in the loop body is executed, which is set =; this is an invalid syntax, therefore set sets the ErrorLevel to 1. The 2> nul portion avoids the message The syntax of the command is incorrect. to be displayed.

要明确设置ErrorLevel，您还可以使用cmd/C exit/B 1.也许这条线更清晰.当然它更灵活，因为您可以声明任何(有符号的 32 位)数字，包括 0 来清除它(省略数字也会清除它).不过在性能方面可能会差一些.

To set the ErrorLevel explicitly you could also use cmd /C exit /B 1. Perhaps this line is more legible. For sure it is more flexible because you can state any (signed 32-bit) number, including 0 to clear it (omitting the number clears it as well). It might be a bit worse in terms of performance though.

以下批处理文件演示了如何应用上述解决方法:

The following batch file demonstrates how the above described work-around could be applied:

:DELETE
echo Deleting "%~1"...
rem this line resets ErrorLevel initially:
cmd /C exit /B
rem this line constitutes the work-around:
for /F "tokens=*" %%# in ('del /F /Q "C:Users
ewuserDesktop\%~1" 2^>^&1 1^> nul') do (2> nul set =)
rem this is the corrected ErrorLevel query:
if not ErrorLevel 1 echo Deleted "%~1" succesfully.
goto :EOF

预设ErrorLevel

除了上面提到的命令cmd/C exit/B，你也可以使用>nul ver 重置ErrorLevel.这可以与 for/F 循环解决方法相结合，如下所示:

Presetting ErrorLevel

Besides the above mentioned command cmd /C exit /B, you can also use > nul ver to reset the ErrorLevel. This can be combined with the for /F loop work-around like this:

> nul ver & for /F "tokens=*" %%# in ('del /F /Q "path	o	hefile_s.txt" 2^>^&1 1^> nul') do (2> nul set =)

没有for/F

的替代方法

代替使用 for/F 来捕获 del 的 STDERR 输出，find 命令也可以像 find/V "" 一样使用，如果传入一个空字符串并且 0<，它会返回 ErrorLevel 的 1/code> 否则:

Alternative Method Without for /F

Instead of using for /F to capture the STDERR output of del, the find command could also be used like find /V "", which returns an ErrorLevel of 1 if an empty string comes in and 0 otherwise:

del "path	o	hefile_s.ext" 2>&1 1> nul | find /V "" 1> nul 2>&1

然而，如果删除成功，这将返回 ErrorLevel 的 1，否则返回 0.为了扭转这种行为，可以像这样附加 if/else 子句:

However, this would return an ErrorLevel of 1 in case the deletion has been successful and 0 if not. To reverse that behaviour, an if/else clause could be appended like this:

del "path	o	hefile_s.ext" 2>&1 1> nul | find /V "" 1> nul 2>&1 & if ErrorLevel 1 (1> nul ver) else (2> nul set =)

不同的方法:在del之后检查文件是否存在

一种完全不同的方法是在尝试删除文件后检查文件是否存在(感谢用户 Sasha 对于提示！)，像这样，例如:

Different Approach: Checking File for Existence After del

A completely different approach is to check the file for existence after having tried to delete it (thanks to user Sasha for the hint!), like this, for example:

del /F /Q "path	o	hefile_s.txt" 1> nul 2>&1
if exist "path	o	hefile_s.txt" (2> nul set =) else (1> nul ver)

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