如何使用PowerShell / RegEx查找空白的所有HTML文件 <title>标签？

Question

I am using Powershell to search thousands of HTML files for files that contain empty <title> tags. These tags may appear in the files with no space, whitespace, or line breaks in between the opening/closing tags. For example, they may look like any of the following

<title></title>

<title>  </title>

<title>
</title>

So far I have the following code

Get-ChildItem locationPath *.htm -Recurse |
    Select-String -pattern '<title>[\s]*</title>' |
    group path |
    select name

This works to provide me a list of all the files that match the first two examples. However, I am struggling to find a way to match the third example in which it has a line break and an unknown amount of whitespace. Any help would be greatly appreciated.

Answer 1

Select-String processes the input line by line, so it won't catch your 3rd example. Try this to get the input as a single string:

Get-ChildItem -Filter '*.htm' -Recurse | Where-Object {
    (Get-Content $_.FullName -Raw) -match '<title>\s*</title>'
} | Select-Object -Expand FullName

Prior to PowerShell v3 you'll need to replace Get-Content -Raw with Get-Content | Out-String Get-Content | Out-String , because the parameter -Raw was introduced with v3.