1.2.0.0/sitecore-hosts.ps1

#
# sitecore_hosts.ps1
#
function Get-DefaultHosts()
{
    return Join-Path -Path $env:windir -ChildPath '\System32\drivers\etc\hosts'
}

<#
    .SYNOPSIS
    Adds host entry to hosts file.
     
    .DESCRIPTION
     
     
    .PARAMETER IpAddress
    The IP address for host entry.
 
    .PARAMETER HostName
    The hostname for host entry.
 
    .PARAMETER Comment
    The comment/description for host entry.
 
    .PARAMETER Path
    The path to the hosts file. The default value is '%WINDIR%\System32\drivers\etc\hosts'
     
    .EXAMPLE
        New-SitecoreHostsEntry -IpAddress 127.0.0.2 -HostName 'HostName4' -Path $hostsFile -Verbose
     
    .EXAMPLE
        New-SitecoreHostsEntry -IpAddress 127.0.0.2 -HostName 'HostName4' -Path $hostsFile -Verbose
#>

function New-SitecoreHostsEntry
{
    [CmdletBinding(SupportsShouldProcess=$true)]
    param (
        [parameter(Mandatory=$true)]
        [string]$IpAddress,
        
        [parameter(Mandatory=$true)]
        [string]$HostName,

        [parameter()]
        [string]$Comment,

        [parameter()]
        [string]$Path = (Get-DefaultHosts)        
    )
    
    Write-Verbose "Processing hosts file: '$Path'"
    Write-Verbose "Add host entry $IpAddress $HostName $Comment"
    
    $matchPattern = '^(?<IP>[0-9a-f.:]+)\s+(?<Hostname>[^\s#]+)(?<Comment>.*)$'
    $found = $false
    [System.Collections.ArrayList]$ArrayList = @()

    if( Test-Path -Path $Path )
    {
        $content = Get-Content -Path $Path
    }
    else
    {
        Write-Warning "File '$Path' not exists."
        return
    }
    
    foreach( $line in $content)
    { 
        if( ($line.StartsWith("#")) -or ($line.Length -eq 0))
        { 
            $ArrayList.Add($line) | Out-Null
            continue 
        }
        elseif( $line -match $matchPattern )
        {
            if( $Matches.Hostname -ne $null )
            {
                if( $Matches.Hostname -eq $HostName )
                {
                    Write-Verbose "Host '$HostName' already exists with $($Matches.IP) $($Matches.Comment)"
                    $found = $true
                }
            }
        }
        $ArrayList.Add($line) | Out-Null
    }
    
    if( -not $found )
    {
        if( [string]::IsNullOrWhiteSpace($Comment) )
        {
            $ArrayList.Add("$IPAddress`t$Hostname") | Out-Null
        }
        else
        {
            $ArrayList.Add("$IPAddress`t$Hostname`t#$Comment") | Out-Null
        }
    
        Set-Content -Path $Path -Value $ArrayList | Out-Null
    }
}


<#
    .SYNOPSIS
    Removes host entry from hosts file.
     
    .DESCRIPTION
     
    .PARAMETER HostName
    The hostname for host entry.
 
 
    .PARAMETER Path
    The path to the hosts file. The default value is '%WINDIR%\System32\drivers\etc\hosts'
     
    .EXAMPLE
        Remove-SitecoreHostsEntry -HostName 'HostName4'
 
#>

function Remove-SitecoreHostsEntry
{
    [CmdletBinding(SupportsShouldProcess=$true)]
    param (
        [parameter(Mandatory=$true)]
        [string]$HostName,

        [parameter()]
        [string]$Path = (Get-DefaultHosts)        
    )
    
    Write-Verbose "Processing hosts file: '$Path'"
    Write-Verbose "Delete host entry $HostName"
    
    $matchPattern = '^(?<IP>[0-9a-f.:]+)\s+(?<Hostname>[^\s#]+)(?<Comment>.*)$'
    $found = $false
    [System.Collections.ArrayList]$ArrayList = @()

    if( Test-Path -Path $Path )
    {
        $content = Get-Content -Path $Path
    }
    else
    {
        Write-Warning "File '$Path' not exists."
        return
    }
    
    foreach( $line in $content)
    { 
        if( ($line.StartsWith("#")) -or ($line.Length -eq 0))
        { 
            $ArrayList.Add($line) | Out-Null
            continue 
        }
        elseif( $line -match $matchPattern )
        {
            if( $Matches.Hostname -ne $null )
            {
                if( $Matches.Hostname -eq $HostName )
                {
                    Write-Verbose "Host '$HostName' exists with $($Matches.IP) $($Matches.Comment)"
                    $found = $true
                }
            }
        }

        if( -not $found )
        {
            $ArrayList.Add($line) | Out-Null
        }
    }
    
    if( $found )
    {
        Set-Content -Path $Path -Value $ArrayList | Out-Null
    }
}

Export-ModuleMember -Function New-SitecoreHostsEntry
Export-ModuleMember -Function Remove-SitecoreHostsEntry