Import-Csv in PowerShell 6.0 supports w3c log format, if delimiter is `,`. https://github.com/PowerShell/PowerShell/pull/2482

iis.csv

#Software: Microsoft Exchange Server
#Version: 15.0.0.0
#Log-type: Transport Connectivity Log
#Date: 2016-09-16T23:30:07.338Z
#Fields: Column1,Column2,Column 3
data1,1,A
data2,2,B
data3,3,C
data4,4,D

iis.log

#Software: Microsoft Internet Information Services 7.5
#Version: 1.0
#Date: 2013-06-24 10:56:45
#Fields: date time s-ip cs-method cs-uri-stem cs-uri-query s-port cs-username c-ip cs(User-Agent) sc-status sc-substatus sc-win32-status time-taken
2013-06-24 10:56:45 192.168.0.1 POST /xas/ - 80 - 222.222.222.222 Mozilla/5.0+(Windows+NT+6.1;+WOW64)+AppleWebKit/537.36+(KHTML,+like+Gecko)+Chrome/27.0.1453.110+Safari/537.36 404 0 2 471

IIS_Schema.xml

<!-- just for logFile section -->
<!-- there's no attribute, value to change delimiter -->
      <element name="logFile">
        <attribute name="logExtFileFlags" type="flags" defaultValue="Date, Time, ClientIP, UserName, ServerIP, Method, UriStem, UriQuery, TimeTaken, HttpStatus, Win32Status, ServerPort, UserAgent, HttpSubStatus, Referer">
          <flag name="Date" value="1"/>
          <flag name="Time" value="2"/>
          <flag name="ClientIP" value="4"/>
          <flag name="UserName" value="8"/>
          <flag name="SiteName" value="16"/>
          <flag name="ComputerName" value="32"/>
          <flag name="ServerIP" value="64"/>
          <flag name="Method" value="128"/>
          <flag name="UriStem" value="256"/>
          <flag name="UriQuery" value="512"/>
          <flag name="HttpStatus" value="1024"/>
          <flag name="Win32Status" value="2048"/>
          <flag name="BytesSent" value="4096"/>
          <flag name="BytesRecv" value="8192"/>
          <flag name="TimeTaken" value="16384"/>
          <flag name="ServerPort" value="32768"/>
          <flag name="UserAgent" value="65536"/>
          <flag name="Cookie" value="131072"/>
          <flag name="Referer" value="262144"/>
          <flag name="ProtocolVersion" value="524288"/>
          <flag name="Host" value="1048576"/>
          <flag name="HttpSubStatus" value="2097152"/>
        </attribute>
        <attribute name="customLogPluginClsid" type="string" defaultValue=""/>
        <attribute name="logFormat" type="enum" defaultValue="W3C">
          <enum name="IIS" value="0"/>
          <enum name="NCSA" value="1"/>
          <enum name="W3C" value="2"/>
          <enum name="Custom" value="3"/>
        </attribute>
        <attribute name="logTargetW3C" type="flags" defaultValue="File">
          <flag name="File" value="1"/>
          <flag name="ETW" value="2"/>
        </attribute>
        <attribute name="directory" type="string" expanded="true" defaultValue="%SystemDrive%\inetpub\logs\LogFiles" validationType="nonEmptyString" />
        <attribute name="period" type="enum" defaultValue="Daily">
          <enum name="MaxSize" value="0"/>
          <enum name="Daily" value="1"/>
          <enum name="Weekly" value="2"/>
          <enum name="Monthly" value="3"/>
          <enum name="Hourly" value="4"/>
        </attribute>
        <attribute name="truncateSize" type="int64" defaultValue="20971520" validationType="integerRange" validationParameter="1048576,4294967295" />
        <attribute name="localTimeRollover" type="bool" defaultValue="false"/>
        <attribute name="enabled" type="bool" defaultValue="true" />
        <attribute name="logSiteId" type="bool" defaultValue="true" />
        <attribute name="flushByEntryCountW3CLog" type="uint" defaultValue="0" />
        <attribute name="maxLogLineLength" type="uint" validationType="integerRange" validationParameter="2,65536" defaultValue="65536" />
        <element name="customFields">
          <attribute name="maxCustomFieldLength" type="uint" validationType="integerRange" validationParameter="2,65536" defaultValue="4096" />
          <collection addElement="add" clearElement="clear">
            <attribute name="logFieldName" type="string" required="true" isUniqueKey="true" validationType="nonEmptyString" />
            <attribute name="sourceName" type="string" required="true" validationType="nonEmptyString" />
            <attribute name="sourceType" type="enum" required="true" >
              <enum name="RequestHeader" value="0"/>
              <enum name="ResponseHeader" value="1"/>
              <enum name="ServerVariable" value="2"/>
            </attribute>
          </collection>
        </element>
      </element>
      <element name="traceFailedRequestsLogging">
        <attribute name="enabled" type="bool" defaultValue="false" />
        <attribute name="directory" type="string" expanded="true" defaultValue="%SystemDrive%\inetpub\logs\FailedReqLogFiles"/>
        <attribute name="maxLogFiles" type="uint" defaultValue="50" validationType="integerRange" validationParameter="1,10000"/>
        <attribute name="maxLogFileSizeKB" type="uint" defaultValue="1024" validationType="integerRange" validationParameter="0,1048576"/>
        <attribute name="customActionsEnabled" type="bool" defaultValue="false"/>
      </element>

import-csv.ps1

 import-csv .\iis_log.log
 
 <#
 date time s-ip cs-method cs-uri-stem cs-uri-query s-port cs-username c-ip cs(User-Agent) sc-status sc-substatus sc-win32-status time-taken
------------------------------------------------------------------------------------------------------------------------------------------
2013-06-24 10:56:45 192.168.0.1 POST /xas/ - 80 - 222.222.222.222 Mozilla/5.0+(Windows+NT+6.1;+WOW64)+AppleWebKit/537.36+(KHTML
 #>
 
 import-csv .\iis_log.csv
 
 # https://github.com/iSazonov/PowerShell/blob/0818b6c921c1970dc294669134266f878352891a/test/powershell/Modules/Microsoft.PowerShell.Utility/assets/TestImportCsv_W3C_ELF.csv
 <#
 Column1 Column2 Column 3
------- ------- --------
data1   1       A
data2   2       B
data3   3       C
data4   4       D
 #>

conslusion

don't think about iis log. But this Import-Csv enhancement will save some w3c log output with delimiter "," product.

description

This change is begin from following issue.

PowerShell/PowerShell#2480

w3c log format is not only for IIS, and IIS could not change log delimiter with schema or web.config.

https://stackoverflow.com/questions/35847585/cant-change-iis-log-field-delimter

not sure about advanced logging, but may possible....?

https://forums.iis.net/t/1191687.aspx?Change+log+file+delimiter+

IIS w3c log, delimited via space, is one of the most unlike format I've ever seen.