PMDF System Manager's Guide

Under some circumstances it can be useful to have PMDF display a welcoming message when a user invokes PMDF via PMDF MAIL or VMS MAIL. Such messages can contain information about the status of the mail system, such as "Our network is down until tomorrow", "The name of system A has been changed to B", "System A is being upgraded and won't be reachable until next week", and so forth.

When PMDF is activated by PMDF or VMS MAIL through the use of a PMDF address (i.e., an address that activates the PMDFSHR image), it attempts to translate the logical name PMDF_WELCOME. If this logical name is not defined (which is normally the case) PMDF will not display anything. If this logical name does translate to some equivalence string, PMDF first checks to see if the first character is an underscore. A leading underscore instructs PMDF to display a welcome message before each and every message is sent. If the underscore is not present the welcome message is only displayed initially; subsequent displays are suppressed unless the value of the logical name changes in some way. The leading underscore, if present, is removed.

PMDF then checks to see if the next character in the string is an at sign. If it is, the remainder of the string is treated as a file name; PMDF opens the file and copies it to the user's terminal. No special privileges are used to open the file; PMDF will not display anything if the file cannot be opened. This makes it possible to use ACLs to protect the file so that only a subset of the user community will see the message. If the next character of the string is not an at sign, PMDF simply displays the string on the user's terminal.

No special privileges beyond those the user normally has are used for any of these operations. The logical name can be defined in the process, job, group or system logical name tables and the mode of the logical name is not relevant.