OpenVMS: Tracing SYLOGIN and Related DCL

This sample code was the subject of “SYS$MANAGER:SYLOGIN.COM - Verification of SYLOGIN processing without disruption”, the July 11, 2010 installment of The OpenVMS Consultant, a column on OpenVMS computing hosted by OpenVMS.org.

This example demonstrates how to selectively trace the DCL commands executed during an OpenVMS process creation on a targeted basis, avoiding collateral damage caused by indiscriminate logging.

The three DCL command files comprising this example may be downloaded from this page. This files make use of a number of techniques, some of which have been featured in previous installments of The OpenVMS Consultant. For your convenience, the files have been packaged in a ZIP archive.

 
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The downloadable ZIP archive contains three example command files:

DCLTRACE_IDENTIFIER.COM SET VERIFY if the current user holds the rightlist identifier TRACE_LOGIN.
DCLTRACE_GROUP.COM SET VERIFY if the Group (LNM$GROUP) or System (LNM$SYSTEM) logical name tables contain a TRACE_LOGIN logical name with the value "TRUE".
DCLTRACE_USERWITHINGROUP.COM SET VERIFY if the username associated with the process is on the list contained in the Group (LNM$GROUP) or System (LNM$SYSTEM)logical name TRACE_LOGIN. This code segment shows how control of tracing can be delegated to users who hold GRPNAM, a far less elevated state than the SYSPRV or other privileges controlling access to the system authorization file.


Download Selective SYLOGIN Trace (OpenVMS ZIP Archive)

References

  • Robert Gezelter “DCL Symbols: Starting at the beginning” The OpenVMS Consultant, OpenVMS.org, March 2, 2009, Retrieved from http://www.openvms.org/stories.php?story=09/03/02/8398294 on July 8,#2010.
  • Robert Gezelter “Pitfalls of F$LOCATE and other Functions” The OpenVMS Consultant, OpenVMS.org, March 31, 2003, Retrieved from http://www.openvms.org/stories.php?story=03/03/31/6547431 on July 8,#2010.
  • Robert Gezelter “Logical Names: Part 5” The OpenVMS Consultant, OpenVMS.org, March 3, 2003, Retrieved from http://www.openvms.org/stories.php?story=03/03/03/4358185 on July 8,#2010.
  • Robert Gezelter “Logical Names: Part 4” The OpenVMS Consultant, OpenVMS.org, February 6, 2003, Retrieved from http://www.openvms.org/stories.php?story=03/02/06/8131783 on July 8,#2010.
  • Robert Gezelter “Logical Names: Part 3” The OpenVMS Consultant, OpenVMS.org, November 4, 2002, Retrieved from http://www.openvms.org/stories.php?story=02/11/04/2738906 on July 8,#2010.
  • Robert Gezelter “Logical Names: Part 2” The OpenVMS Consultant, OpenVMS.org, October 17, 2002, Retrieved from http://www.openvms.org/stories.php?story=02/10/17/9372652 on July 8,#2010.
  • Robert Gezelter “Logical Names: Part 1” The OpenVMS Consultant, OpenVMS.org, September 24, 2002, Retrieved from http://www.openvms.org/stories.php?story=02/09/24/5441505 on March 11,#2010.
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