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This seems like a simple task but I can't seem to get it to work. I want to be able to read a text file and if two exact patterns are found return True. If it only finds one then it returns false.

I tried this, but it is not working:

Get-Content $log_path | Select-String -pattern "\bInstallation of\b|\bfailed\b" -AllMatches -quiet

What can I try next?

halfer
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Jason Murray
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1 Answers1

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Your pattern contained a or | statement which basically says.

If one or the other (Installation or failed) is present, then it's a match. What you want is to use a wildcard instead so both word and the in-between are part of the same match. 

Select-String -pattern "\bInstallation .* failed\b"  -quiet

Additional Notes

When having issues, there are online regex tester to allow you to test your regular expression.

I personally like a lot RegexHero even though you need IE because it is done in Silverlight because it has an Analyze section for your regular expression which breaks down your expression and gives an explanation in words of what you are doing.

Super useful when learning or just when dealing with always more complex epxressions.

For instance, your initial regular expression. Initial expression

Although I did not personally used it, RegexStorm also looks promising and is not IE restricted.

Sage Pourpre
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    The `-AllMatches` is not relevant here. – Martin Brandl Oct 04 '17 at 13:11
  • Thanks so much, that was the issue. I spent way too long on this :-) Appreciate the assistance. – Jason Murray Oct 04 '17 at 13:12
  • Good point @MartinBrandl . I did not look up its effect prior to answer. I removed that part. – Sage Pourpre Oct 04 '17 at 13:18
  • @JasonMurray I added a Regex tester note. You should take a look. Whenever I have to deal with Regular expression, I use one of these tools to ensure it is resilient to more complex interaction and / or to fix problems with my matches. It saved me countless hours. – Sage Pourpre Oct 04 '17 at 13:19