Editing Comparison of command shells (section)

=== Restricted shell subset ===
Several shells can be started or be configured to start in a mode where only a limited set of commands and actions is available to the user. While not a security ''boundary'' (the command accessing a resource is blocked rather than the resource) this is nevertheless typically used to restrict users' actions before logging in.

A restricted mode is part of the [[POSIX]] specification for shells, and most of the Linux/Unix shells support such a mode where several of the built-in commands are disabled and only external commands from a certain directory can be invoked.<ref>{{cite web |url=http://pwet.fr/man/linux/commandes/posix/sh |title=man sh - shell, the standard command language interpreter / posix |language=fr |publisher=Pwet.fr |access-date=2013-08-18 |archive-url=https://web.archive.org/web/20141221210713/http://pwet.fr/man/linux/commandes/posix/sh |archive-date=21 December 2014 |url-status=dead }}</ref><ref>{{cite web |url=https://www.gnu.org/software/bash/manual/html_node/The-Restricted-Shell.html |title=Bash Reference Manual: The Restricted Shell |publisher=Gnu.org |date=2010-12-28 |access-date=2013-08-18}}</ref>

PowerShell supports restricted modes through ''session configuration files'' or session configurations. A session configuration file can define visible (available) cmdlets, aliases, functions, path providers and more.<ref>{{cite web |url=https://technet.microsoft.com/en-us/library/hh849712.aspx |title=New-PSSessionConfigurationFile |publisher=Technet.microsoft.com |access-date=2013-08-18}}</ref>