select-string을 사용합니다.

PS F:\TEST\ps> get-help select-string

이름

  Select-String

개요

  문자열 및 파일에서 텍스트를 찾습니다.
  

구문

  Select-String [-Path] <string[]> [-Pattern] <string[]> [-AllMatches] [-Case
  Sensitive] [-Context <Int32[]>] [-Encoding <string>] [-Exclude <string[]>] 
  [-Include <string[]>] [-List] [-NotMatch] [-Quiet] [-SimpleMatch] [<CommonP
  arameters>]
  
  Select-String -InputObject <psobject> [-Pattern] <string[]> [-AllMatches] [
  -CaseSensitive] [-Context <Int32[]>] [-Encoding <string>] [-Exclude <string
  []>] [-Include <string[]>] [-List] [-NotMatch] [-Quiet] [-SimpleMatch] [<Co
  mmonParameters>]

PS F:\TEST\ps> select-string "updateLog" log.log

log.log:2:updateLogStatus Start
log.log:4:updateLogStatus END

텍스트 내용에 추가적으로, 파일명과, 줄번호가 함께 출력됩니다.

[파일명]:[줄번호]:[텍스트]

foreach 구문을 통해서 출력합니다.

PS F:\TEST\ps> select-string "updateLog" log.log | foreach{$_.line}
updateLogStatus Start
updateLogStatus END

사용가능한 함수는 아래와 같이 확인합니다.

PS F:\TEST\ps> select-string "updateLog" log.log | get-member

 TypeName: Microsoft.PowerShell.Commands.MatchInfo

Name         MemberType Definition                                             
----         ---------- ----------                                             
Equals       Method     bool Equals(System.Object obj)                         
GetHashCode  Method     int GetHashCode()                                      
GetType      Method     type GetType()                                         
RelativePath Method     string RelativePath(string directory)                  
ToString     Method     string ToString(), string ToString(string directory)   
Context      Property   Microsoft.PowerShell.Commands.MatchInfoContext Conte...
Filename     Property   System.String Filename {get;}                          
IgnoreCase   Property   System.Boolean IgnoreCase {get;set;}                   
Line         Property   System.String Line {get;set;}                          
LineNumber   Property   System.Int32 LineNumber {get;set;}                     
Matches      Property   System.Text.RegularExpressions.Match[] Matches {get;...
Path         Property   System.String Path {get;set;}                          
Pattern      Property   System.String Pattern {get;set;}