4. Gestión de archivos en PowerShell para administradores de sistemas

Los sistemas de archivos permiten organizar los datos en los dispositivos de almacenamiento siguiendo una serie de normas y restricciones. Un sistema de archivos se implanta después de crear una partición en un dispositivo de almacenamiento (disco duro, USB, CD/DVD, etc.).

La unidad principal de los sistemas de archivos es el archivo, en general, los sistemas operativos distinguen entre estos tipos de archivos:

  • Normales: los archivos pueden contener cualquier tipo de información.
  • Directorios: son archivos que contienen información sobre la organización y estructura de otros archivos.
  • Especiales: estos archivos permiten comunicarse con dispositivos de E/S.

Los archivos tienes propiedades:

  • Nombre: sirve para identificar un archivo.
  • Extensión: la extensión sirve para saber el tipo de programa que lo ejecuta o interpreta.
  • Tipo de archivo: pueden dividirse en normales, directorios o especiales.
  • Ubicación: lugar del sistema de archivos donde se encuentra un archivo.
  • Tamaño: cantidad de bytes que ocupa un fichero en el sistema de archivos.
  • Fecha de creación, modificación y último acceso: para cada archivo indica la fecha en que ha sido creado, modificado y la última vez que se accedió a él.
  • Atributos: son propiedades que permiten asignar características especiales a los archivos.
  • Permisos: se utilizan para permitir o restringir el acceso a los archivos a determinados usuarios o grupos. Los permisos pueden ser para: leer, modificar, eliminar, renombrar, etc.

A continuación se verán las operaciones que se pueden realizar con archivos y directorios.

Archivos

Las operaciones que se pueden realizar con archivos son:

  • Información sobre archivos

  • Crear archivos

  • Almacenar contenido en un archivo

  • Agregar contenido a un fichero

  • Vaciar el contenido de un fichero

  • Ver el contenido de un fichero

  • Importar el contenido de un fichero

  • Importar el contenido de un fichero XML

  • Exportar el contenido a un fichero

  • Exportar el contenido a un fichero XML

  • Copiar archivos

  • Eliminar ficheros

  • Mover archivos

  • Renombrar

  • Imprimir

  • Comprimir

  • Descomprimir

  • Asignar permisos a archivos

Directorios

Las operaciones que se pueden realizar con directorios son:

  • Crear un una carpeta

  • Cambiar de directorio

  • Listar el contenido de un directorio

  • Copiar carpetas

  • Borrar carpetas

  • Mover carpetas

  • Renombrar carpetas

  • Comprimir

  • Descomprimir

  • Permisos

  • Compartir

File System Security PowerShell Module 3.2.3

Source are available on CodePlex

https://ntfssecurity.codeplex.com/

Download

https://gallery.technet.microsoft.com/scriptcenter/1abd77a5-9c0b-4a2b-acef-90dbb2b84e85/file/48905/1/NTFSSecurity%201.3.zip

Introduction

Managing permissions with PowerShell is only a bit easier than in VBS or the command line as there are no cmdlets for most day-to-day tasks like getting a permission report or adding permission to an item. PowerShell only offers Get-Acl and Set-Acl but everything in between getting and setting the ACL is missing. This module closes the gap.

Documentation

For documentation plese refer to:

Comments, feature requests and bug reports are very welcome: raandree@live.com

Installation

Just create the folder „NTFSSecurity“ in one of the standard module folders and copy the files attached in there. The standard module folders are in the environment variable %PSModulePath%, for example C:\Users\\Documents\WindowsPowerShell\Modules.
For example, all the files in the zip file have to be in „C:\Users\raandree\Documents\WindowsPowerShell\Modules\NTFSSecurity“. If you did this then the module should be listed in „Get-Module -ListAvailable“ and can be imported using „Import-Module NTFSSecurity“.

Description

The module provides 10 cmdlets to manage permissions on the file system, like adding and removing ACEs, setting the inheritance, getting the current permissions or even get the effective permissions for a certain user.
The available cmdlets are listed below with a short description. More information can be retreived in the PowerShell using Get-Help.

The name / SID translation is done by the Security2 class:
Security2 1.2.zip

All cmdlets have at least one parameter that supports the pipeline. They all can work with pipeline input coming from Get-ChildItem but some do more with what comes form the pipeline. For excample you can remove permission by piping what Get-Ace returns to Remove-Ace:

The pipeline support can also be used to backup and restore permissions of one or many items:

All cmdlets can handle SIDs and also SamAccountNames. The output contains always both unless a SID is not resolvable.

The types.ps1xml file is extending the common objects with some useful information and the format.ps1xml file formats all the output in almost the same way like the Get-ChildItem output.

By implementing the [Process Privilege http://processprivileges.codeplex.com/] project the cmdlets can activate the required privileges for setting the ownership for example.

Add-Ace

Adds a specific ace to the current object. This can be done in just one line:

Get-Ace

Gives you a list of all permissions . normally you are interested not in the inherited permissions so the switch ExcludeInherited can be useful

Filtering works with Where-Object

Get-OrphanedAce

Lists all permissions that can no longer be resolved. This normally happens if the account is no longer available so the permissions show up as a SID and not as an account name.
To remove all non-resolvable or orphaned permissions you can use the following line. But be very careful with that as maybe the account is not resolvable due to a network problem.

Remove-Ace

Removes the permission for a certain account. As the pipeline is supported it takes also

Get-EffectivePermissions

Shows the permissions an account actually has on a file or folder. If no parameter is specified it shows the effective permissions for the current user. However you can supply a user by using the SID or account name

Get-Inheritance

Shows if inheritance is blocked

Enable-Inheritance

It can be a problem if certain files or folders on a volume have inheritance disabled. Making sure that inheritance is enabled can be done using this cmdlets:

Disable-Inheritance

See Enable-Inheritance

Get-Owner

Shows the owner of a file or folder

Set-Owner

Sets the owner to a specific account like:

More information

https://gallery.technet.microsoft.com/scriptcenter/1abd77a5-9c0b-4a2b-acef-90dbb2b84e85

Windows PowerShell aliases

 

Saving Data as a Comma-Separated Values File

The Export-Csv cmdlet makes it easy to export data as a comma-separated values (CSV) file; all you need to do is call Export-Csv followed by the path to the CSV file. For example, this command uses Get-Process to grab information about all the processes running on the computer, then uses Export-Csv to write that data to a file named C:\Scripts\Test.txt:

 

By default, data is saved in ASCII format. What if you’d prefer to save the data in Unicode format (or maybe UTF7 or UTF8)? No problem; just add the -encoding parameter followed by the desired format:

 

You might have noticed that the first line in the resulting CSV file lists the .NET object type:

 

If you’d just as soon not have the .NET object type in your output file then simply include the -notype parameter:

 

Another parameter you might find useful is -force. Suppose Test.txt is a read-only file: that enables people to access, but not change, the contents of the file. That’s great, until it comes time to use Export-Csv and update the contents of the file. Here’s what happens if you try to export text to a read-only file:

 

That’s where -force comes into play. Suppose you add -force to your export command:

 

In that case, Windows PowerShell will temporarily clear the read-only attribute from the file, update the contents, and then reset the read-only attribute. The end result: the file gets updated, but when Export-Csv is finished the file will still be marked as read-only.