regex - PowerShell 正则表达式不工作

Question

我有以下 PowerShell 脚本:

$SCRIPTNAME = "myfile.js"
$SUBJECT = Get-Content $SCRIPTNAME | Out-String
if ($SUBJECT -match ".*/// COMMENT.*?$(.*)")
{
    echo $matches[1];
}
$Host.UI.RawUI.ReadKey('NoEcho,IncludeKeyDown');

它生成以下错误(我正在尝试使用正则表达式捕获组，但它不起作用):

.* : The term '.*' is not recognized as the name of a cmdlet, function, script file, or operable program. Check the
spelling of the name, or if a path was included, verify that the path is correct and try again.
At C:\Users\User\Desktop\install.ps1:21 char:39
+ if ($SUBJECT -match ".*/// COMMENT.*?$(.*)")
+                                        ~~
    + CategoryInfo          : ObjectNotFound: (.*:String) [], CommandNotFoundException
    + FullyQualifiedErrorId : CommandNotFoundException

为什么第二个捕获组的 .* 部分出现问题？

Answer 1

明白了。我需要用单引号 ' ' 转义正则表达式，并进一步添加单行和多行说明符 (?sm):

$SCRIPTNAME = "myfile.js"
$SUBJECT = Get-Content $SCRIPTNAME | Out-String
if ($SUBJECT -match '(?sm).*/// COMMENT.*?$(.*)' -and $matches.Count -ge 2)
{
    echo $matches[1];
}
$Host.UI.RawUI.ReadKey('NoEcho,IncludeKeyDown');