[fa.info-vax] set prompt/carriage_control

info-vax@ucbvax.ARPA (07/16/85)

From: Provan@LLL-MFE.ARPA


Can anyone tell me what the purpose of the /(no)carriage_control
switch in the Set Prompt command is?  As far as I can tell, the
only difference this makes is that the prompt will go to the
next line if you have your terminal echo turned off with the
switch (the default), but it will come out on the same line if
it isn't.  There must be a more important reason.

While I'm being puzzled over this, can anyone tell me why the
leading <crlf> that's /carriage_control prepends to the prompt
is discarded normally?  For example, if I'm at the DCL prompt
and type <cr>, one would expect, given that my prompt is
/carriage_control, that there would be a blank line between the
two DCL prompts, but there isn't.  I'm not complaining, I just
don't understnad why all this work is being done to append
the <crlf> by making /carriage_control the default only to
strip it when the prompt gets output.  There is some (unwritten?)
law at work here that I don't understand.  Anyone know what it is?