PMP Mail Archive: Re: PMP> ISSUE: CR/LF, not just LF, to mark lines in prtChannelInfo,

PMP Mail Archive: Re: PMP> ISSUE: CR/LF, not just LF, to mark lines in prtChannelInfo,

Re: PMP> ISSUE: CR/LF, not just LF, to mark lines in prtChannelInfo,

David_Kellerman@nls.com
Wed, 16 Jul 1997 10:44:43 PST

> There are several places in the Printer MIB where a LF by itself
> is indicated as the way to separate lines. But US-ASCII and NVT ASCII
> both specify that lines are ended with the two character sequence
> CR (carriage return = decimal 13) and LF (line feed = decimal 10).
> If you send ONLY a LF to a display console (eg, an NMS), you will NOT
> reposition to the first column for the next fragment and these strings
> will be displayed incorrectly (as a cascade to the right).
> This is because LF is only a vertical motion in US-ASCII and NVT ASCII.
> It is UNIX and C that have the convention that LF by itself is a new-line.
>
> The following objects are affected:
>
> 1. The 'prtChannelInformation' object specifies ONLY an LF (line feed)
> as a delimiter and NOT a CR/LF pair (consistent with MIME mail and HTTP
> header usage, US-ASCII and NVT ASCII usage).

Leave it alone. We dicusssed this extensively when working on the
prtChannelInformation object. Tom, if you recall, at one point you were
advocating using a vertical bar (|) as the delimiter, and you ended up
agreeing to the use of linefeed (with the suggestion that we indicate
its code value in the description).

There's a long discussion in the e-mail, but the gist of it is that the
prtChannelInformation is intended primarily as machine-readable
material, not human-readable text. The NVT ASCII encoding was chosen
primarily as a way of "normalizing" the grab-bag of things that had to
be encoded in the object. The linefeed delimiter was chosen somewhat
arbitrarily (any value outside of the printable ASCII set would have
sufficed) -- the important consideration was that it not be a code that
could appear in an attribute value. In other words, the linefeed is
just a marker; it's not a formatting code.

:: David Kellerman Northlake Software 503-228-3383
:: david_kellerman@nls.com Portland, Oregon fax 503-228-5662