Question

我正在将数千行批处理代码转换为PowerShell。我正在使用正则表达式来帮助完成这个过程。问题是代码的一部分是：

$`$2

更换后，它只显示$2并且不展开变量。我还使用单引号替换第二部分而不是转义变量，结果相同。

$origString = @'
IF /I "%OPERATINGSYSTEM:~0,6%"=="WIN864" SET CACHE_OS=WIN864
...many more lines of batch code
'@

$replacedString = $origString -replace "(IF /I `"%)(.+)(:.+%`"==`")(.+`")(.+)","if ( $`$2 -match `"^`$4 ) {`$5 }"

$replacedString

Answer 1

您可以尝试这样的事情：

$origString -replace "(IF /I `"%)(.+)(:.+%`"==`")(.+`")(.+)",'if ($$$2 -match "^$4" ) {$5 }'

请注意$$$2。评估结果为$和$2的内容。

一些代码向您展示差异。亲自尝试一下：

'abc' -replace 'a(\w)', '$1'
'abc' -replace 'a(\w)', "$1"  # "$1" is expanded before replace to ''
'abc' -replace 'a(\w)', '$$$1'
'abc' -replace 'a(\w)', "$$$1" #variable $$ and $1 is expanded before regex replace
                               #$$ and $1 don't exist, so they are expanded to ''

$$ = 'xyz'
$1 = '123'
'abc' -replace 'a(\w)', "$$$1`$1" #"$$$1" is expanded to 'xyz123', but `$1 is used in regex

Answer 2

尝试这样：

 $replacedString = $origString -replace "(IF /I `"%)(.+)(:.+%`"==`")(.+`")(.+)","if ( $`$`$2 -match `"^`$4 ) {`$5 }"

PowerShell：-replace，regex和（$）美元符号问题

2 个答案: