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Monday, October 1, 2018

Replace first character in string Powershell


In today's tutorial, we will be addressing a common scenario - replacing the first character in a string when working with text files in PowerShell. Specifically, I encountered a case where I needed to remove the leading "|" character from several lines in a large text file.

The Problem

I was working with a text file of over 10 MB, where some lines began with the "|" character. Here's a snippet to give you an idea:

|-*/A1101 |A|param,string,egal|A1|A11|margin-right:11px;font-size:10px;¤ |-*/A1102 |A|param,string,egal|A1|A11|margin-right:11px;font-size:10px;¤ -*/A1103 |A|param,string,egal|A1|A11|margin-right:11px;font-size:10px;¤ |-*/A1104 |A|param,string,egal|A1|A11|margin-right:11px;font-size:10px;¤ -*/A1105 |A|param,string,egal|A1|A11|margin-right:11px;font-size:10px;¤

Our goal? Remove that first "|" character where it appears.

The PowerShell Solution

To achieve this, we can utilize PowerShell's Get-Content to read the file, and then TrimStart method to remove any leading "|" character. Here's the step-by-step breakdown:

  1. First, we'll read the content of the file.

PS C:\Users\cloudtech> $content = Get-Content C:\content\file1.txt
  1. Next, for each line in the content, we'll trim off the starting "|".

PS C:\Users\cloudtech> $contenttrim = $content | ForEach-Object { $_.TrimStart("|"," ") }
  1. Lastly, we'll output the processed content to a new file.

PS C:\Users\cloudtech> $contenttrim | Out-File C:\content\file1-output.txt

 

The Result

After executing the above, the resulting file will appear as:

-*/A1101 |A|param,string,egal|A1|A11|margin-right:11px;font-size:10px;¤ -*/A1102 |A|param,string,egal|A1|A11|margin-right:11px;font-size:10px;¤ -*/A1103 |A|param,string,egal|A1|A11|margin-right:11px;font-size:10px;¤ -*/A1104 |A|param,string,egal|A1|A11|margin-right:11px;font-size:10px;¤ -*/A1105 |A|param,string,egal|A1|A11|margin-right:11px;font-size:10px;¤

And there you have it! A quick and efficient way to process and clean up large text files in PowerShell. Whether you're a seasoned pro or a newcomer to PowerShell, I hope you found this tutorial helpful. Stay tuned for more tips and tricks!