public/Invoke-Grep.ps1

<#
.SYNOPSIS
    Search text or file content for matching string pattern
.DESCRIPTION
    Search text or file content for matching string pattern
.PARAMETER Pattern
    Text pattern to search for
.PARAMETER InputString
    String to search for matching Pattern value
.PARAMETER Path
    Path to search files for matching Pattern value. If Path is provided, InputString is ignored
.PARAMETER Recurse
    Optional. Only used with Path parameter. Default is to scan files
    in the Path location only, not sub-folders. If Recurse is used, scan
    will include sub-folders
.EXAMPLE
    Invoke-Grep -Pattern "Contoso Corp" -InputString "The facility is owned by Contoso Corp, who recently leased it."
.EXAMPLE
    Invoke-Grep -Pattern "Contoso Corp" -Path "c:\mydocs" -Recurse
.LINK
    https://github.com/Skatterbrainz/helium/blob/master/docs/Invoke-Grep.md
#>

function Invoke-Grep {
    param (
        [parameter(Mandatory)][string]$Pattern,
        [parameter()][string]$InputString = "",
        [parameter()][string]$Path,
        [parameter()][switch]$Recurse
    )
    if (![string]::IsNullOrWhiteSpace($Path)) {
        Get-ChildItem -Path $Path -Recurse:$Recurse | Select-String $Pattern
    } elseif (![string]::IsNullOrWhiteSpace($InputString)) {
        $InputString | Select-String $Pattern
    }
}