问题

你可以尝试以下方式来实现你的需求：

powershell "$progresspreference='silentlycontinue'; $response = Invoke-WebRequest -Uri 'https://thisismyurl.com/123456' -Method Head; if ($response.StatusCode -ne 200) { echo 'Download failed! URL is invalid or expired.'; pause; goto label; } else { wget -uri 'https://thisismyurl.com/123456' -outfile '%userprofile%\Downloads\file.zip' }"

这个命令将首先使用Invoke-WebRequest来检查 URL 是否有效，如果状态码不是 200，则会输出错误信息并跳转到 label。如果 URL 有效，它将继续下载文件。

至于你提到的将 PowerShell 命令分开的问题，你可以使用分号 ; 来分隔多个命令，或者将它们放在多行上，如上面的示例所示。不过，请确保在适当的位置添加分号或换行，以保持语法正确性。

powershell "$progresspreference='silentlycontinue'; wget -uri "https://thisismyurl.com/123456" -outfile '%userprofile%\Downloads\file.zip'"

powershell "$progresspreference='silentlycontinue' `
wget -uri "https://thisismyurl.com/123456" -outfile '%userprofile%\Downloads\file.zip'"

答案1

得分: 2

* 调用 [`powershell.exe`](https://learn.microsoft.com/en-us/powershell/module/microsoft.powershell.core/about/about_powershell_exe) 时，使用隐含的 `-Command` 参数，表示命令字符串中 *最后一条语句* 决定了 `powershell.exe` 的退出代码：成功时为 `0`，否则为 `1`。

  * 在 Windows PowerShell 中，`wget` 是 [`Invoke-WebRequest`](https://learn.microsoft.com/en-us/powershell/module/Microsoft.PowerShell.Utility/Invoke-WebRequest) cmdlet 的别名，与任何 cmdlet 一样，如果在执行过程中发生 *任何* 错误，其成功状态被视为 `$false`，因此转换为退出代码 `1`。

  * 因此，可以简单地使用 `cmd.exe` 的 `||` 运算符处理 `powershell.exe` 退出代码为 _非零_ 的情况。

* 对于来自批处理文件的 *多行* PowerShell CLI 调用，请参阅 [此答案](https://stackoverflow.com/a/69439031/45375)。简而言之：无法使用总体 `"..."` 封闭，因此必须使用 `^` 转义选定字符，并且必须在每个内部行末尾使用 `^`。

在代码的上下文中综合起来：

@echo off & setlocal

powershell $progresspreference='silentlycontinue'; ^
wget -uri 'https://thisismyurl.com/123456' ^
-outfile '%userprofile%\Downloads\file.zip' ^
|| (echo download failed! url is invalid. & pause & goto label)

exit /b 0

:label
echo failure-handling branch...
exit /b 1

<details>
<summary>英文:</summary>

&lt;!-- language-all: sh --&gt;

* You&#39;re calling [`powershell.exe`](https://learn.microsoft.com/en-us/powershell/module/microsoft.powershell.core/about/about_powershell_exe), the Windows PowerShell CLI, with the implied `-Command` parameter, which means that the success status of the *last statement* in the command string determines `powershell.exe`&#39;s exit code: `0` in the success case, `1` otherwise.

  * In Windows PowerShell, `wget` is an alias for the [`Invoke-WebRequest`](https://learn.microsoft.com/en-us/powershell/module/Microsoft.PowerShell.Utility/Invoke-WebRequest) cmdlet, and, as with any cmdlet, if *any* error occurs during its execution, its success status is considered `$false` and therefore translates to exit code `1`.

  * Therefore, you can simply use `cmd.exe`&#39;s `||` operator to act on the case where `powershell.exe`&#39;s exit code is _non-zero_.

* As for *multiline* PowerShell CLI calls from a batch file, see [this answer](https://stackoverflow.com/a/69439031/45375). In short: you cannot use overall `&quot;...&quot;` enclosure and must therefore `^`-escape select characters, and you must end each interior line with `^`

To put it all together in the context of your code:

@echo off & setlocal

powershell $progresspreference='silentlycontinue'; ^
wget -uri 'https://thisismyurl.com/123456' ^
-outfile '%userprofile%\Downloads\file.zip' ^
|| (echo download failed! url is invalid. & pause & goto label)

exit /b 0

:label
echo failure-handling branch...
exit /b 1

</details>