Add-HostFileEntry

1.0.1

Add-HostFileEntry.psm1

#Requires -Version 3
#Requires -Modules AdministratorRole
Set-StrictMode -Version:Latest

function Add-HostFileEntry {
  param(
    [parameter(Mandatory=$true,position=0)]
    [string]$hostName,
    [string]$ipAddress = '127.0.0.1'
  );
    Assert-AdministratorRole;

    $hostsLocation = "$env:windir\System32\drivers\etc\hosts";
    $hostsContent = Get-Content -Path $hostsLocation -Raw;
    
    $ipRegex = [regex]::Escape($ipAddress);
    $hostRegex = [regex]::Escape($hostName);
    
    $existingEntry = $hostsContent -match "(?:`n|\A)\s*$ipRegex\s+$hostRegex\s*(?:`n|\Z)";
    if(-not $existingEntry) {
        if ($hostsContent -notmatch "`n\s*$") {
            # Add line break if missing from last line
            Write-Verbose -Message "Adding blank line to $hostsLocation";
            Add-Content -Path $hostsLocation -Value '';
        }

        Write-Verbose -Message "Adding entry mapping $hostName to $ipAddress to $hostsLocation";
        Add-Content -Path $hostsLocation -Value "$ipAddress`t`t$hostName";
    } else {
        Write-Verbose -Message "Entry mapping $hostName to $ipAddress already exists in $hostsLocation";
    }
<#
.SYNOPSIS
    Adds an entry to the HOSTS file
.DESCRIPTION
    If it doesn't already exist, adds a line to the HOSTS file mapping the given host name to the given IP address
.PARAMETER hostName
    The host name to map
.PARAMETER ipAddress
    The IP address to map
#>
}

function Remove-HostFileEntry {
  param(
    [parameter(Mandatory=$true,position=0)]
    [string]$hostName,
    [string]$ipAddress = '127.0.0.1'
  );
    Assert-AdministratorRole;

    $hostsLocation = "$env:windir\System32\drivers\etc\hosts";
    
    $ipRegex = [regex]::Escape($ipAddress);
    $hostRegex = [regex]::Escape($hostName);

    Write-Verbose -Message "Removing entry mapping $hostName to $ipAddress from $hostsLocation";
    Edit-File -Path $hostsLocation -Pattern "(?:`n|\A)\s*$ipRegex\s+$hostRegex\s*(?:`n|\Z)" -Replacement "`n" -SingleString;
<#
.SYNOPSIS
    Removes an entry from the HOSTS file
.DESCRIPTION
    Updates the HOSTS file to remove a line mapping the given host name to the given IP address
.PARAMETER hostName
    The host name to remove
.PARAMETER ipAddress
    The IP address to remove
#>
}

Export-ModuleMember -Function Add-HostFileEntry;
Export-ModuleMember -Function Remove-HostFileEntry;