How can I use Powershell to remove dupliation within a file?

Posted on 2014-09-23
Last Modified: 2014-09-24
I am currently working with this script.

I need to convert this script to a Powershell script.
It looks within a file for duplication, and if there is duplication it deletes the duplication.


REM Defile file location
set File1=c:\Programs\New.txt
set Workfile=c:\Programs\Temp\_workfile_.txt

REM Error if file does not exist
if not exist "%File1%" (
  goto :next_Script

REM Remove duplicate lines from the file
  copy NUL "%Workfile%" >NUL
  for /f "tokens=* usebackq" %%B in ("%File1%") do (
    findstr /b /e /c:"%%B" /i "%Workfile%">NUL || echo.%%B>>"%Workfile%"
  copy /y "%Workfile%" "%File1%" >NUL
  if exist "%Workfile%" del "%Workfile%"
Question by:100questions
  • 5
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LVL 28

Accepted Solution

becraig earned 500 total points
ID: 40340147
easy one liner
gc .\current-file.txt | sort -unique | out-file newfile.txt

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LVL 28

Expert Comment

ID: 40340209
Are you doing this for more than one file ?

Author Comment

ID: 40341599
Actually, I am amalgamating files together, combining that is.. copy *.txt newfile.txt and then I need to remove any duplication within the file itself.  
It needs to check any duplication line by line, comparing lines to lines etc..

Author Comment

ID: 40341631
The script does not work as expected, it's reorganizing all the data into alpha order.  Perhaps I should have made this clearer.  
It need to look at every line and remove any lines which are duplicates, respecting the order of the data which currently exists.
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Author Comment

ID: 40341736
I have posted another question which is much clearer.

Author Closing Comment

ID: 40341975
This removes duplication of lines, however in the context of what I am looking for it needs to keep one set of data, between a start marker and an end marker as it were.  This does not respect that structure.  I have opened another question which is much more detailed and cleared.
LVL 28

Expert Comment

ID: 40342122
Great, I will look out for it.

I should be able to make a minor modification and get you to do exactly what you need without changing the sorting of the data.

Author Comment

ID: 40342147
Thanks for your help.

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