CODEWITHSUNDEEP
powershell
user3088731
user3088731

Reputation: 67

Shell Programming Regex error

I have a text file and I want to display a content from the file after searching for a word pattern.

My text file has following 

Hello 2013, a7

Hello 2013, z8
errorprocessing adafda adasd adads adasdad adadsasd asdadsdasd adasdasdasda dadsadasda

Hello 2013, e1

My display should be

user: z8 
error: errorprocessing adafda adasd adads adasdad adadsasd asdadsdasd adasdasdasda dadsadasda

I could search errorproceesing pattern and display the content but I am unable to display xyz008 as this is a dynamic word and it may differ from one text file to another.

I need to search for 

Hello [0-9][0-9][0-9][0-9][a-z][0-9]

But I am not able get the desired output

I want to implement in Powershell I have Select-String -Pattern [0-9][0-9][0-9][0-9][A-Z][0-9] -AllMatches -SimpleMatch –

Upvotes: 1

Views: 78

Answers (1)

mklement0
mklement0

Reputation: 439193

Try the following (substitute your input filename for file):

do { # Dummy loop so we can exit the pipeline prematurely with `break`.
  get-content file | % {
    if ($_ -match '^Hello (\d{4}), ([a-z0-9]+)$') { # username found
      # Save it.
      $userName = $matches[2]
    } elseif ($_ -match '^errorprocessing ') { # error line found
      # Output desired result.
      "user: $userName`r`nerror: $_"
      # Exit pipeline (via dummy loop).
      break
    }
  }
} while ($false)

Note: The assumption is that you want to display only one username, namely the most recent one preceding the error line.

  • The loop is necessary, because Select-String will not match across lines.
  • A username is saved in the same variable whenever it is encountered, effectively only storing the most recent one.
  • Once the error line is found, the most recent user name and the error line are output, as desired, and the pipeline is exited (in order to exit the pipeline with break before processing ALL lines, it had to be wrapped in a (dummy) loop).

Upvotes: 2

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