functions/Get-DbaTraceFile.ps1

function Get-DbaTraceFile {
    <#
        .SYNOPSIS
        Gets a list of trace file(s) from specied SQL Server Instance
 
        .DESCRIPTION
        This function returns a list of Trace Files on a SQL Server Instance and identify the default Trace File
 
        .PARAMETER SqlInstance
        A SQL Server instance to connect to
 
        .PARAMETER SqlCredential
        A credeial to use to conect to the SQL Instance rather than using Windows Authentication
 
        .PARAMETER Default
        Switch that will only return the information for the default system trace
 
        .PARAMETER Silent
        Use this switch to disable any kind of verbose messages
             
        .NOTES
        Tags: Security, Trace
 
        Author: Garry Bargsley (@gbargsley), http://blog.garrybargsley.com
 
        Website: https://dbatools.io
        Copyright: (C) Chrissy LeMaire, clemaire@gmail.com
        License: GNU GPL v3 https://opensource.org/licenses/GPL-3.0
 
        .EXAMPLE
        Get-DbaTraceFile -SqlInstance sql2016
 
        Lists all the tracefiles on the sql2016 SQL Server.
             
        .EXAMPLE
        Get-DbaTraceFile -SqlInstance sql2016 -Default
 
        Lists the default trace information on the sql2016 SQL Server.
             
#>

    [CmdletBinding()]
    Param (
        [parameter(Position = 0, Mandatory, ValueFromPipeline)]
        [Alias("ServerInstance", "SqlServer")]
        [DbaInstanceParameter[]]$SqlInstance,
        [PSCredential]$SqlCredential,
        [switch]$Default,
        [switch]$Silent
    )
    
    process {
        
        foreach ($instance in $SqlInstance) {
            try {
                $server = Connect-SqlInstance -SqlInstance $instance -SqlCredential $SqlCredential -MinimumVersion 9
            }
            catch {
                Stop-Function -Message "Failure" -Category ConnectionError -ErrorRecord $_ -Target $instance -Continue
                return
            }
            
            $sql = "SELECT id, status, path, max_size, stop_time, max_files, is_rowset, is_rollover, is_shutdown, is_default, buffer_count, buffer_size, file_position, reader_spid, start_time, last_event_time, event_count, dropped_event_count FROM sys.traces"

            try {
                $results = $server.Query($sql)
            }
            catch {
                Stop-Function -Message "Issue collecting trace data on $server" -Target $server -ErrorRecord $_
            }
            
            if ($Default) {
                $results = $results | Where-Object { $_.is_default }
            }
        }

        foreach ($row in $results) {
            [PSCustomObject]@{
              ComputerName  = $server.NetName
              InstanceName  = $server.ServiceName
              SqlInstance   = $server.DomainInstanceName
              Id              = $row.id
              Status        = $row.status
              Path          = $row.path
              MaxSize        = $row.max_size
              StopTime      = $row.stop_time
              MaxFiles        = $row.max_files
              IsRowset       = $row.is_rowset
              IsRollover       = $row.is_rollover
              IsShutdown     = $row.is_shutdown
              IsDefault        = $row.is_default
              BufferCount   = $row.buffer_count
              BufferSize    = $row.buffer_size
              FilePosition  = $row.file_position
              ReaderSpid    = $row.reader_spid
              StartTime        = $row.start_time
              LastEventTime = $row.last_event_time
              EventCount    = $row.event_count
              DroppedEventCount = $row.dropped_event_count
            } 
        }
    }
}