add-prefix.ps1

Function Add-Prefix([switch]$inputObject,$io) {
    BEGIN {
        if ($inputObject) {$io | &($MyInvocation.InvocationName) $args; break;}
      $args = @($io) + $args
		  $prefix = $args[0]
        Write-host "Adding $prefix as a prefix..."
    }
    PROCESS {
	 	  $name = $_.Name
		  if ($name.StartsWith($prefix)) {
		  		Write-Host "ignored: $name"
		  }
		  else 
		  {
        		mv $_.Name "$prefix$name"
		  		Write-Host "renamed: $prefix$name".
		  }
    }
    END {
      $x = 0
      #$args | % { $x++; "$x - $_" }
       Write-host "End"
    }
}

Function Remove-Prefix([switch]$inputObject,$io) {
    BEGIN {
        if ($inputObject) {$io | &($MyInvocation.InvocationName) $args; break;}
      $args = @($io) + $args
		  $prefix = $args[0]
        Write-host "Removing $prefix as a prefix..."
    }
    PROCESS {
	 	  $name = $_.Name
		  if ($name.StartsWith($prefix)) {
		  		$newName = $name.Substring($prefix.Length);
        		mv $_.Name "$newName"
		  		Write-Host "renamed: $newName"
		  }
		  else 
		  {
		  		Write-Host "ignored: $name".
		  }
    }
    END {
      $x = 0
      #$args | % { $x++; "$x - $_" }
       Write-host "End"
    }
}

Function Add-Postfix([switch]$inputObject,$io) {
    BEGIN {
        if ($inputObject) {$io | &($MyInvocation.InvocationName) $args; break;}
      $args = @($io) + $args
		  $postfix = $args[0]
        Write-host "Adding $postfix as a postfix..."
    }
    PROCESS {
			$ext = $_.Extension
	 	  $name = $_.Name
			$stem = $name.Substring(0,$name.Length - $ext.Length)
		  if ($stem.EndsWith($postfix)) {
		  		Write-Host "ignored: $name"
		  }
		  else 
		  {
				$newName = "$stem$postfix$ext"
        mv $_.Name "$newName"
		  	Write-Host "renamed: $newName"
		  }
    }
    END {
      $x = 0
      #$args | % { $x++; "$x - $_" }
       Write-host "End"
    }
}

Function Remove-Postfix([switch]$inputObject,$io) {
    BEGIN {
        if ($inputObject) {$io | &($MyInvocation.InvocationName) $args; break;}
      	$args = @($io) + $args
		  	$postfix = $args[0]
        Write-host "Removing $postfix as a postfix..."
    }
    PROCESS {
			$ext = $_.Extension
	 	  $name = $_.Name
			$stem = $name.Substring(0,$name.Length-$ext.Length)
		  if ($stem.EndsWith($postfix)) {
		  		$newStem = $stem.Substring(0, $stem.Length-$postfix.Length);
					$newName = "$newStem$ext"
        	mv $_.Name "$newName"
		  		Write-Host "renamed: $newName"
		  }
		  else 
		  {
		  		Write-Host "ignored: $name"
		  }
    }
    END {
      $x = 0
      #$args | % { $x++; "$x - $_" }
       Write-host "End"
    }
}