![]() To be on the safe side: use single quotes and your regular expression groups will work fine in PowerShell.įunnily enough it was not the first time I had problems with regular expressions that looked similar to. NET are the same! Scripting-needs differ from application-programming-needs. As they also the dollar-sign, they "suffer" from the same problem, so use single quotes: $article = $article -replace '(?s).*\s*(?.*)\s*.*', '$ also works? Final thoughtsĭon't assume PowerShell and. Sometimes named group captures improve readability of your code. If you are adamant on using double quotes, you must escape your dollar signs with a `: $article = $article -replace "(?s).*\s*(.*)\s*.*", "`$1" What about named capture replacement? The following is more PowerShell-esque and actually works: $article = $article -replace '(?s).*\s*(.*)\s*.*', '$1' But I love my double quotes. We do not have a variable named $1, so that's why our article is replaced by an empty string. But to a PowerShell developer, a double quote means a string that supports variable replacement: "hello $name". NET developer the double quote is a string ( "hello") and the single quote a char ( 'c'). The main problem has to do with quotation. but now I end up with an empty string! ? Quotation matters! To change the behavior into single line mode, you can specify the (?s) to your expression, like this: $article = $article -replace "(?s).*\s*(.*)\s*.*", "$1"Īgain: it compiles. Regular expression options: (?s)įirst, we need to understand the way regular expression matching works in PowerShell: the default mode is that. it does not do anything! I end up with exactly the same string I had. My first attempt was the following code: $article = $article -replace ".*\s*(.*)\s*.*", "$1" $article = "$article" Fail on the first try $article = Invoke-WebRequest $url -UseBasicParsing First, we'll download a blog into a string, like this: $ErrorActionPreference = "Stop" Let's create some dataĪnything is better with an example, so let's use PowerShell to download a blog and extract the article content using a regular expression. When creating regular expression or replacement string, use single quoted strings and you'll avoid a world of pain! Also make sure you use the proper regular expression options. I had this experience when I tried to parse some HTML with PowerShell: I could not get the replacement with regular expression groups to work! It turned out that my. It is a language for writing scripts, so you might encounter some unexpected situations. NET, so it is no surprise that it is very popular with. ![]()
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