Firstly we will look at how to search the content from the string and file. For that select-string cmdlet is there which helps in finding the pattern from the string or file

Features of select-string cmdlet:

• Select-String cmdlet uses the regular expression to find the string pattern in strings or files.
• Select-String is based on a line of text and searches pattern through each line and stops after the first matches.
• It returns the object if the pattern matches found else the null object returns.

Syntax of Select-String:

[-Pattern] <String[]>
[-Path] <String[]>

PowerShell Code 1 (Without Function):

search.ps

$filePath = "C:\Users\HP\OneDrive\Desktop\demo.txt"
$selectString = "the good day with rohit sahu"
$check = select-string -pattern $selectString -path $filePath
if($check -eq $null){
   Write-output "String Not Found"
}
else{
   Write-output "String Found"
}

PowerShell Code 2 (With Function):

search.ps

function search-string{
   $filePath1 = "C:\Users\HP\OneDrive\Desktop\demo.txt"
   $selectString1 = "hello Rohit sahu"
   
   $chck = select-string -Path $filepath1 -Pattern $selectString1
   
   if($chck -eq $null){
       Write-output "String Not Found"
   }   
   else{
       Write-output "String Found"
   }
}
search-string

Replace the Content from the String or File

For the Replace the content we have some cmdlet Get-Content and Set-Content this cmdlet helps in fetching and replacing the content from the file or string, with the help of this cmdlet we can read and replace any kind of content inside the file whether it’s a complicated or single word. Powershell has the capability to replace the content about anything.

Syntax of Get-Content:

Get-Content -Path $filePath

This will return the content from the file ((Get-Content -path $filePath ) -replace ‘old_Word’,’new_Word’) | Set-Content -Path $filePath

PowerShell Code:

replace.ps$content = ((Get-Content -Path $filePath) -replace ‘how are you i’,’I know that you’ | Set-Content -Path $filePath)

$content1 = Get-Content -Path $filePath
Write-output $content1