Documentation for CLR-Based Alternatives to xp_cmdshell

Question

Documentation for CLR-Based Alternatives to xp_cmdshell

Abhishek Modi (amodi) 0

Hi Team,

Since extended stored procedures are deprecated, is there any source code or documentation available for a CLR-based alternative to Microsoft system-defined extended stored procedures such as xp_cmdshell?

Thanks,

Abhishek Modi

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Answer 1

Erland Sommarskog 124.3K MVP Volunteer Moderator

Yes. Here you can find how to write a stored procedure in the CLR: https://learn.microsoft.com/en-us/sql/relational-databases/clr-integration/database-objects/getting-started-with-clr-integration?view=sql-server-ver17&tabs=cs.

To start a command-line process from .NET, you would use the class System.Diagnostics.Process.

You will have to piece the things together yourself. Keep in mind that once you are in the CLR, it is quite possible that you can achieve what you want to do through .NET directly, without spawning a subprocess. As one example, see this blog post from Raul Garcia: https://techcommunity.microsoft.com/blog/sqlserver/using-clr-to-replace-xp-cmdshell-for-specific-tasks/384391.

Abhishek Modi (amodi) 0 Reputation points

2025-07-09T07:00:02.01+00:00

Hi @Erland Sommarskog ,

Thank you for your response.

I wanted to check if there is any CLR-based source code, Microsoft documentation, or official article available for the following system-defined extended stored procedures:

xp_availablemedia

xp_dirtree

xp_instance_regenumvalues

xp_instance_regenumkeys

xp_instance_regread

xp_msver

xp_regread

xp_sqlagent_notify

xp_servicecontrol

I understand that these procedures are part of the legacy SQL Server architecture and are generally undocumented or only lightly documented by Microsoft. However, any official references or insights into their CLR based internal implementation would be greatly appreciated.

Many Thanks,

Abhishek
Erland Sommarskog 124.3K Reputation points MVP Volunteer Moderator

2025-07-09T07:52:15.66+00:00

There is certainly nothing official in the terms of CLR, but Google might be able to help you to find third-party implementations of some of the extended stored procedures above.

However, in the case of xp_dirtree there is an alternative through a DMV sys.dm_os_enumerate_filesystem, which has been there since SQL 2017, but which is not officially documented. There is however a KB article that describes how these can be enabled/disabled: https://support.microsoft.com/en-us/topic/kb4046638-add-the-ability-to-disable-or-enable-a-few-new-dmvs-and-dmfs-introduced-in-sql-server-2017-05d709c5-4522-3168-2cb1-f755fddff9e7

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Documentation for CLR-Based Alternatives to xp_cmdshell

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