OpenVMS: Tracing SYLOGIN and Related DCL
This sample code was the subject of “SYS$MANAGER:SYLOGIN.COM - Verification of SYLOGIN processing without disruption”, the July 11, 2010 installment of The OpenVMS Consultant, a column on OpenVMS computing hosted by OpenVMS.org.
This example demonstrates how to selectively trace the DCL commands executed during an OpenVMS process creation on a targeted basis, avoiding collateral damage caused by indiscriminate logging.
The three DCL command files comprising this example may be downloaded from this page. This files make use of a number of techniques, some of which have been featured in previous installments of The OpenVMS Consultant. For your convenience, the files have been packaged in a ZIP archive.
The downloadable ZIP archive contains three example command files:
DCLTRACE_IDENTIFIER.COM | SET VERIFY if the current user holds the rightlist identifier TRACE_LOGIN. |
DCLTRACE_GROUP.COM | SET VERIFY if the Group (LNM$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. |