jon@UCB-VAX.ARPA (Jon Corbet) (09/07/85)
I have encountered some interesting behavior from SMG, and I was
wondering if anybody else has seen this one...I have a program that essentially
wants to clear a terminal screen, so it does the following:
smg$create_pasteboard ( --- );
smg$create_virtual_display ( --- );
smg$paste_virtual_display ( --- );
smg$erase_display ( --- );
smg$delete_virtual_display ( --- );
smg$delete_pasteboard ( --- );
where the specific parameters have been omitted. Now, this procedure does
indeed clear the terminal screen, but: it leaves a channel assigned to the
terminal whose screen has just been cleared. It seems that the call to
smg$create_pasteboard actually assigns two channels (I found all this with
a combination of DEBUG and SDA) and smg$delete_pasteboard only deassigns one
of them.
Has anybody else seen this, and is there a way around it? The program
of interest wants to go out and clear all terminals that are not logged in; it
becomes rather inconvenient when it retains channels to all of those terminals,
preventing them from being logged in to...
jon
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Jonathan Corbet
National Center for Atmospheric Research, Field Observing Facility
{seismo|hplabs}!hao!boulder!jon (Thanks to CU CS department)