CODEWITHSUNDEEP
powershellcase-sensitive
Lery
Lery

Reputation: 135

Check if a specific word in a string contains capital using Powershell

I am checking a registry key using get-childitem with the -recurse option. I am piping that into Get-ItemProperty, where I'm looking for a specific value of a string value. I am then selecting that object. I want to further enhance my script to add an If statement. I only want to do something If one word in my string contains a capital letter. The trick is, only that specific word and no other words.

The value of my string value looks like this: Https:\\Blah.blah.com

So in the above, only the if statement to be true if "https" contains a capital. Above, it does contain a capital. If however the value returned is something like https:\\CapitalLettersHereareOK.com. Then the If statement should return false.

I can't use -cmatch because, while it works, it's matching the entire string. As outlined above, some of the letters in the string could be capital, and that is ok. I just need to know if "HTTPS" contains any capital letters.

I'm no good at Regex and I'm pretty sure that is needed here. See code below:

$GetWebValue = Get-ChildItem -Path 'HKLM:\Software\MySoftwareKey' -Recurse -ErrorAction SilentlyContinue | Get-ItemProperty -Name Web -ErrorAction SilentlyContinue | Select-object -expandproperty Web

Upvotes: 2

Views: 1304

Answers (1)

mklement0
mklement0

Reputation: 437618

The key is to isolate the protocol name (everything before :) and test only it for the presence of uppercase characters; e.g.:

PS> ('Https:\\Blah.blah.com' -split ':')[0] -cmatch '\p{Lu}'
True  # ditto for 'httpS:\\...', 'hTtps:\\...', 'HTTPS:\\...', ...

PS> ('https:\\Blah.blah.com' -split ':')[0] -cmatch '\p{Lu}'
False

  • (... -split ':')[0] extracts the first : based token from the LHS string, i.e., the protocol name.

  • -cmatch case-sensitively matches regex \p{Lu} (an uppercase letter) anywhere in that protocol name.

    • Note: In this simple case, where it's safe to assume that only ASCII-range letters a through z can be part of a protocol name, regex [A-Z] would suffice; by contrast, \p{Lu} matches any uppercase Unicode character classified as a letter.

In the context of your command:

Get-ChildItem -Path 'HKLM:\Software\MySoftwareKey' -Recurse -ErrorAction SilentlyContinue |
  Get-ItemProperty Web -ErrorAction SilentlyContinue | 
    Select-Object -ExpandProperty Web |
      Where-Object { ($_ -split ':')[0] -cmatch '\p{Lu}' }

Note that while you should be able to use Get-ItemPropertyValue Web (PSv5+) instead of the roundabout Get-ItemProperty Web | Select-Object -ExpandProperty Web, so as to directly extract just the data from each matching registry value, this is not an option as of this writing, due to a known bug.

Upvotes: 3

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