将Powershell变量传递到Windows批处理文件 [英] Passing Powershell variable to Windows Batch file

问题描述

由于我的项目以及部署方式的限制，我需要在批处理文件中运行powershell命令，并从powershell脚本中回显变量.该脚本通过RS-232从电视上检索型号，并以十六进制形式返回该型号.

我编写了脚本，并将其精巧地压缩为可以运行的一行.我什至可以在命令行中使用"powershell -command"[myCondensedScript]"，效果很好

/f %% a的

 ，用于('powershell.exe -command"$ port = New-Object System.IO.Ports.SerialPort COM1，9600，none，8，one; [byte [] $reqSerial = 1,48,65,48,65,48,54,2,67,50,49,55,3,112,13; [byte []] $ reqModel = 0x01,0x30,0x41,0x30,0x41,0x30，0x36,0x02,0x43,0x32,0x31,0x37,0x03,0x70,0x0D; [byte []] $ response =''; [byte []] $ readData =''; $ port.DTREnable = $ True; $ port.Open(); $ port.Write($ reqModel，0，$ reqModel.Count); $ x = 0; do {$ x ++; $ readData = $ port.ReadChar(); If($ x -eq 13 -or$ x -eq 14-或$ x -eq 15-或$ x -eq 16-或$ x -eq 17-或$ x -eq 18-或$ x -eq 19-或$ x -eq 20-或$x -eq 21){$ response + = $ readData;};} while($ response.Length -ne 9); $ port.Close(); $ hexResponse = $ response.forEach([char]); $ hexResponseString =[string] $ hexResponse; $ hexResponseString = $ hexResponseString.replace(''，''); $ finalHex = $ hexResponseString + 0; Write-Host $ finalHex;"^;(Get-Variable -ValueOnly -Name finalHex ^).值")将HexCode = %% a设置为回声％HexCode％ 

输出就是

  echo + 

预期输出为

 <代码> 563332330 

我不确定变量缺少什么，因为我对变量和批处理文件不是很熟练.我在Google上进行了广泛的搜索，发现此页面对 https://ss64.com/nt/for有所帮助.html 我只是不明白如何将%% a分配给我想要的确切变量.任何帮助将不胜感激！

解决方案

您的命令已在封闭的'...'字符串的上下文中未转义嵌入的'字符，将无法正常工作.

相反，使用 usebackq 解析选项，然后将命令括在`...` 中，简化了引号和转义.

以下示例命令演示了该技术(要在 cmd.exe 提示符下尝试此方法，而不是从批处理文件中尝试，请将 %% a 替换为％a ):

对于/f"usebackq delims =" %% a in(`powershell -c"$ finalHex ='0x68 0x69'-替换'0x |'; $ finalHex"`)设置"HexNum = %% a"回声％HexNum％

上面打印了以下内容，证明嵌入的"..." ，'...'和; 的工作原理如下:是(在使用"..." 的上下文中，将PowerShell命令传递给 -c ( -Command )整体，这会阻止 cmd.exe 解释内容):

  6969 

---

使用 中的PowerShell命令传递到 -c /-Command 参数(在 Windows PowerShell 中为隐含，但在PowerShell [Core] 6+中为必需).

• 由于 cmd.exe 无法解释"..." 字符串的内容(除了％...％环境-可以直接使用 cmd.exe 元字符(具有特殊句法含义的字符，例如& ).

单引号(')可以原样使用.

如果需要在整个"..." 命令字符串中嵌入双引号("):

• 在PowerShell [Core] 6+( pwsh.exe )中，使用" .
• 在Windows PowerShell( powershell.exe )中，使用 \" ，但请注意，然后将对字符串内部的空格进行标准化 (折叠成单个空间)； \"避免了这种情况，但随后要求您 ^ 逸出任何 cmd.exe 元字符，例如& .

 用于/f"usebackq delims =" %% i in(`REM在PowerShell [Core] 6+(pwsh.exe)中，使用"代替\"powershell -noprofile -c(\""hi& there \").Replace('i'，'@')"`)做@echo [%% i] 

上面的结果(注意归一化的空格；在PowerShell [Core] 6+中带有" 的情况不会发生)

  [hi&那里] 

---

关于您的特定命令:

• 删除 ^ (插入符号)，因为使用 ...... 引用不再需要它们；将整个传递给 powershell -c 的命令包含在"..." 中.

• 防止输出流受到污染，以确保仅返回感兴趣的值，这意味着:

  • 删除 Write-Host 命令.

  • 将 $ null = ... 放在 $ port.Open()， $ port.Write(...)， $ port.Close()调用以确保它们不会隐式创建输出(请参见

    for /F %%a in ('powershell.exe -command "$port = New-Object System.IO.Ports.SerialPort COM1, 9600, none, 8, one;[byte[]] $reqSerial = 1,48,65,48,65,48,54,2,67,50,49,55,3,112,13;[byte[]] $reqModel = 0x01,0x30,0x41,0x30,0x41,0x30,0x36,0x02,0x43,0x32,0x31,0x37,0x03,0x70,0x0D;[byte[]] $response = '';[byte[]] $readData = '';$port.DTREnable = $True;$port.Open();$port.Write($reqModel, 0, $reqModel.Count);$x=0;do {$x++;$readData = $port.ReadChar();If($x -eq 13 -or $x -eq 14 -or $x -eq 15 -or $x -eq 16 -or $x -eq 17 -or $x -eq 18 -or $x -eq 19 -or $x -eq 20 -or $x -eq 21) {$response += $readData;};}while($response.Length -ne 9);$port.Close();$hexResponse = $response.forEach([char]);$hexResponseString = [string]$hexResponse;$hexResponseString = $hexResponseString.replace(' ','');$finalHex = $hexResponseString+0;Write-Host $finalHex;"^; (Get-Variable -ValueOnly -Name finalHex^).value') do set HexCode=%%a
    
    echo %HexCode%
    

    The output is simply

       echo +
    

    The expected output would be

    563332330
    

    I'm not sure what I'm missing with the variable, as I'm not terribly skilled with variables and batch files. I have googled extensively and found this page to be somewhat helpful https://ss64.com/nt/for.html I just don't understand how I assign %%a to the exact variable I want. Any help would be greatly appreciated!

    解决方案

    Your command has unescaped embedded ' characters in the context of the enclosing '...' string, which won't work.

    Instead, use the usebackq parsing option and enclose the command in `...`, which simplifies quoting and escaping.

    The following sample command demonstrate the technique (to try this at the cmd.exe prompt instead of from a batch file, replace %%a with %a):

    for /f "usebackq delims=" %%a in (`
      powershell -c "$finalHex = '0x68 0x69' -replace '0x| '; $finalHex"
    `) do set "HexNum=%%a"
    echo %HexNum%
    

    The above prints the following, proving that embedded "...", '...', and ; worked as-is (in the context of using "..." for the enclosing quoting around the PowerShell command passed to -c (-Command) as a whole, which prevents cmd.exe from interpreting the contents):

    6969
    

    ---

    To summarize the usebackq rules with PowerShell's CLI:

    • Pass the PowerShell commands enclosed in "..." as a whole to the -c / -Command parameter (which is implied in Windows PowerShell, but required in PowerShell [Core] 6+).

      • Since cmd.exe doesn't interpret the contents of "..." strings (except %...% environment-variable references), cmd.exe metacharacters (characters with special syntactic meaning, e.g., &) can be used as-is.

    • Single quotes (') can be used as-is.

    • If you need to embed double quotes (") inside the overall "..." command string:

      • In PowerShell [Core] 6+ (pwsh.exe), use "".
      • In Windows PowerShell (powershell.exe), use \"", but note that string-internal whitespace will then be normalized (folded into a single space); \" avoids that, but then requires you to ^-escape any cmd.exe metacharacters such as &.

    for /f "usebackq delims=" %%i in (`
      REM In PowerShell [Core] 6+ (pwsh.exe), use "" instead of \""
      powershell -noprofile -c "(\""hi &    there\"").Replace('i', '@')"
    `) do @echo [%%i]
    

    The above yields (note the normalized whitespace; in PowerShell [Core] 6+ with "" this wouldn't happen):

    [hi & there]
    

    ---

    As for your specific command:

    • Remove the ^ (carets), as they are no longer needed with the `...` quoting; enclose the commands passed to powershell -c as a whole in "...".

    • Prevent pollution of the output stream to make sure that only the value of interest is returned, which means:

      • Remove the Write-Host command.

      • Place $null = ... before the $port.Open(), $port.Write(...), $port.Close() calls to make sure that they do not implicitly create output (see this answer for an explanation).

    • Simply use $finalHex by itself as the last statement in order to output it (no need for (Get-Variable ...)).

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