Set-String.ps1

<#
.SYNOPSIS
    Used to replace text in a file.   
.EXAMPLE
   Get-ChildItem -Recurse | Set-String -Pattern "c:\documents" -ReplaceWith "c:\users"
.EXAMPLE
   Set-String -Pattern "c:\documents" -ReplaceWith "c:\users" -Path c:\temp\script.ps1 
#>
Function Set-String
{
    [CmdLetBinding()]
    param(
        [Parameter(
            Position = 0,
            ValueFromPipeline = $true,
            ValueFromPipelineByPropertyName = $true
            )]
        [Alias("fullname")]
        [string[]]$Path,
        
        [Parameter(
            Mandatory   = $true,
            HelpMessage = "The pattern to be replaced",
            Position    = 1,
            ValueFromPipelineByPropertyName = $true
            )]
        [string]$Pattern,

        [Parameter(
            Mandatory   = $true,
            HelpMessage = "The replacment text",
            Position    = 2,
            ValueFromPipelineByPropertyName = $true
            )]
        [string]$ReplaceWith     
    )
    
    process
    {
        $Speed = Measure-Command {
            foreach($currentFile in (resolve-path $Path))
            {
                $Encoding = Get-FileEncoding $currentFile

                Write-Verbose "Checking $CurrentFile"
                (Get-Content $currentFile -raw) -replace $Pattern, $ReplaceWith | 
                    Set-Content $currentFile -Encoding $Encoding
            }
        }
        Write-Verbose "Processed in $($Speed.Seconds) Seconds"
    }
}