我在想这样的事

$filename = "c:\temp\test.txt";
$pattern1 = "^(?<date>[^\s]+)\sE!\s(?<message>.*)";
$pattern2 = "^(?<type>[^:]+):(?<value>.*)"

$errors = Select-String -Path $filename -Pattern $pattern1

$table = [System.Collections.ArrayList]::new()

foreach($row in $errors.Matches)
{
   $newRow = New-Object -TypeName psobject
   $date = [DateTime]$row.Groups["date"].Value
   $newRow | Add-Member -NotePropertyName Date -NotePropertyValue $date

   $splitMessages = $row.Groups["message"].Value.Split(",");
   
   for($i = 0; $i -lt $splitMessages.Count; $i++)
   {
      write-host "split = " $splitMessages[$i]
      $splitMessages[$i] -match $pattern2
Write-Host $Matches
$Matches  | Format-Table
      $newRow | Add-Member -NotePropertyName ('type' + ($i + 1)) -NotePropertyValue $Matches.type
      $newRow | Add-Member -NotePropertyName ('message' + ($i + 1)) -NotePropertyValue $Matches.value
   }

   $table.Add($newRow)  | Out-Null
}

$table

输出

Date     : 8/30/0021 12:07:46 AM
type1    : message
message1 :  send request failed
type2    :  original error
message2 :  Post "https://test.com/": dial tcp 172.31.11.121:443: i/o timeout

Date     : 8/30/2021 12:07:46 AM
type1    : system
message1 :  code: RequestError
type2    :  message
message2 :  send request failed
type3    :  original error
message3 :  Post "https://test.com/": dial tcp 172.31.11.121:443: i/o timeout

Date     : 8/29/2021 10:15:46 PM
type1    : err
message1 :   AccessDenied: User: test is not authorized to perform: PutData status code: 403
type2    :  request id
message2 :  f1171fd0-05b6-4f7d-bac2-629c8594c46e

您可以读取日志文件并按如下方式筛选错误值：

$errorList = @{
    'AccessDenied' = 'permissions'
    'i/o timeout'  = 'connectivity'
}

$errorDesc = @{                                                                        
    'permissions'  = 'The user does not have permission to perform the action, please reach out to your administrator'
    'connectivity' = 'The agent has failed to connect to one of the required endpoints. Please ensure the instance (and any proxy - if configured) is able to connect to all required endpoints. For more information on the required endpoints, please refer to https://helpmefixthis.com/'
}

$log = 'X:\Somewhere\TheLogFile.log'
$errorsFound = Get-Content -Path $log | ForEach-Object {
    foreach ($key in $errorList.Keys) {
        if ($_ -match $key) {
            # output an object
            [PsCustomObject]@{
                Error       = $key
                Description = $errorDesc[$errorList[$key]]
            }
            break
        }
    }
}

# view on console
$errorsFound | Format-List

# save this in a text file
$errorsFound | Format-List | Out-String | Set-Content -Path 'X:\Somewhere\TheErrors.txt'

# save this in a CSV file you can open in Excel
$errorsFound | Export-Csv -Path 'X:\Somewhere\TheErrors.csv' -NoTypeInformation -UseCulture

在控制台上，这将输出（使用您的示例）：

Error       : i/o timeout
Description : The agent has failed to connect to one of the required endpoints. Please ensure the instance (and any proxy - if configured) 
              is able to connect to all required endpoints. For more information on the required endpoints, please refer to https://helpmef
              ixthis.com/

Error       : i/o timeout
Description : The agent has failed to connect to one of the required endpoints. Please ensure the instance (and any proxy - if configured) 
              is able to connect to all required endpoints. For more information on the required endpoints, please refer to https://helpmef
              ixthis.com/

Error       : AccessDenied
Description : The user does not have permission to perform the action, please reach out to your administrator