Powershell Regex is only returning first result

Question

Why is my regex pattern only returning the name/value of the first test ? I thought .+ would make it a non greedy pattern.

This is my code

$value = "Starting test: Connectivity
          Starting test: CheckSecurityError
          Starting test: DFSREvent"


$value -match 'Starting test: (?<testName>.+)' 

$matches.testName

This is my output

True
Connectivity

If it's like other regex engines, dot doesn't match newlines unless you tell it to. Also the way you have it, the capturing group will include the seconds two "Starting test: " strings, as well as all the whitespace. — Dewi Morgan, Jun 29 '17 at 15:16
Possible duplicate of [How to capture multiple regex matches, from a single line, into the $matches magic variable in Powershell?](https://stackoverflow.com/questions/3141851/how-to-capture-multiple-regex-matches-from-a-single-line-into-the-matches-mag) — TessellatingHeckler, Jun 29 '17 at 17:17

score 1 · Answer 1 · answered Jun 29 '17 at 17:00

$value = @"
Starting test: Connectivity
Starting test: CheckSecurityError
Starting test: DFSREvent
"@

$Pattern = '^\s*Starting test: (?<testName>.+?)$'
($value -split '\n')|
    Where-Object {$_ -match $Pattern }|
      ForEach{$matches.testname}

"-----------------"
## alternative without named capture group

$value -split '\n' | 
  select-string -pattern  'Starting test: (.+)' -all | 
    ForEach {$_.matches.groups[1].value}

Sample output:

Connectivity
CheckSecurityError
DFSREvent
-----------------
Connectivity
CheckSecurityError
DFSREvent

score 1 · Answer 2 · edited Sep 22 '17 at 02:03

One approach would be to use the .Net class, System.Text.RegularExpressions.Regex:

$value = "Starting test: Connectivity
          Starting test: CheckSecurityError
          Starting test: DFSREvent"
$regex = [System.Text.RegularExpressions.Regex]::new('Starting test: (?<testName>.+)')
$regex.Matches($value) | %{$_.Groups['testName'].value}

#or by calling the static method rather than instantiating a regex object:
#[System.Text.RegularExpressions.Regex]::Matches($value, 'Starting test: (?<testName>.+)') | %{$_.Groups['testName'].value}

Output

Connectivity
CheckSecurityError
DFSREvent

MS Documentation: https://learn.microsoft.com/en-us/dotnet/standard/base-types/regular-expressions

Or you can use Select-String as mentioned in other answers / only using %{$_.Groups['testName'].value to pull back the relevant capture groups' values from your matches.

$value | 
    select-string -Pattern 'Starting test: (?<testName>.+)' -AllMatches | 
    % Matches | 
    %{$_.Groups['testName'].value}

score 0 · Answer 3 · answered Jun 29 '17 at 15:14

0

You should use select-string:

$value -split '\n' | sls 'Starting test: (?<testName>.+)' | % { Write-Host 'Result' $_ }

answered Jun 29 '17 at 15:14

majkinetor

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How would i do this as a multi line regex ? – KingBain Jun 29 '17 at 15:29
Add the `-AllMatches` parameter on the `select-string` call. Not strictly `multi-line` in the regex definition (i.e. changing the behaviour of `^` and `$`, but it means it's able to return more than one match, which I think's what you're after. i.e. Acts as if the Global modifier were applied (https://www.w3schools.com/jsref/jsref_regexp_g.asp) – JohnLBevan Jun 29 '17 at 17:39

Powershell Regex is only returning first result

3 Answers3