Re: Patch: small reduction in output from make doc

[Phil Holmes]

----- Original Message ----- 
From: "David Kastrup" <address@hidden>
To: "Phil Holmes" <address@hidden>
Cc: "Graham Percival" <address@hidden>; <address@hidden>
Sent: Thursday, June 16, 2011 9:27 PM
Subject: Re: Patch: small reduction in output from make doc


> "Phil Holmes" <address@hidden> writes:
>
> > TBH, I don't agree at all.  I personally think there's nothing worse
> > than a process that takes place in the background and gives no
> > indication that anything is happening.  I've frequently interrupted
> > git grep for this reason - just to see if it's actually doing
> > something.  My response would be - in Unix, if you don't want to see
> > the "normal" output, then add a 1>/dev/null - it's simple enough.
>
> Lilypond does not produce "normal" output, but mostly garbage.
>
> And random garbage from an overly talkative program is not a progress
> indicator since you can't actually rely on it.

This is what I get from her:

Processing `D:/Music/LilyPondDev/BugSquad/Harkins.ly'
Parsing...
Interpreting music...
Preprocessing graphical objects...
Finding the ideal number of pages...
Fitting music on 1 page...
Drawing systems...
Layout output to `Harkins.ps'...
Converting to `./Harkins.pdf'...
success: Compilation successfully completed

If that's garbage, then what would count as progress indicators?

> Lilypond is commonly is called from a Makefile and other utilities,
> obliterating all useful output from them.
>
> The normal behavior for a Unix utility is to write to stderr when
> something goes wrong and then bottom out with a non-zero exit status.
> Make (or similar tools) stop, and the output on the screen is relevant
> to what command was called last, what went wrong, and where the process
> stopped.
>
> That's relevant.  Highly so.

I would agree that progress messages should go to stdout, and error messages 
to stderr so that "normal" progress could be distinguished from "important" 
error.

> If you write things like 1>/dev/null or similar in the Makefile, you
> don't get useful output when something goes wrong.

Um.  No you don't.  You're redirecting stdout, so if the program is properly 
written, stderr messages still appear on the terminal.

> Mixing the important stuff with garbage means you either have to hunt
> for the important stuff within the garbage, or you don't get the
> important stuff at all.

See above.  Progress should go to stdout which can then be hidden if desired 
with 1>/dev/null.  Errors to stderr which would only be hidden if stream 2 
is redirected.

--
Phil Holmes