Re: very simple off-topic question regarding command line viewing of postscript files on macOS

[Kenneth Wolcott]

Thank you all for your responses.

I'm not at all offended by the XY type of response.

I'll try to elaborate without TMI...

  I use Preview with maximum width for my external monitor and minimum
height, to display what I am engraving from, and then scroll it down
line by line.

  I then have a terminal window (multi-tabbed) immediately beneath it
to the right, all the way to the bottom.

  I use command line emacs (not GUI or Windows style) in the terminal
window to edit Lilypond source.

  I then use control-Z to suspend the emacs session, and run my script
(written in Perl) which calls Lilypond and then displays the resultant
pdf using Reader (another pdf app distinct from Preview).

  I specify Reader to display the pdf because if I don't the pdf will
be displayed by Preview in a tab which is totally useless to view an
entire page of output when it is in the same size as my origin pdf.

  I have not seen an effective way to prevent the tabbed Preview.  It
looks like some developer decided that multiple files must be
displayed as a tab for efficiency rather than having two instances of
the app.  Breaks my desired workflow :-(

  Now, I want to make changes (or add new content)...the existing
Reader app instance will not update automatically and will not update
manually; I have to exit it and re-execute (my script will execute it,
but is unable to exit it, so I have to exit manually).

  If my script could kill the existing Reader app instance and start
another one, that would be great, but pstree/pkill (Apple built-in
process view and kill commands) apparently have no effect on either
Preview or Reader (or any app for that matter).

  So there's lots of keystrokes (or mouse clicks) that interfere with
the visual process and the hand-and-eye coordination is disrupted.
This is extremely annoying.

  It would be nice if I could do almost everything inside emacs.  Even
if that's not possible, removing some of these extra moving parts
might help with the workflow.  I'd like to have the script have more
control over the environment.  My script is a very simple wrapper
around Lilypond, not near as powerful or sophisticated as a makefile,
but similar.

  I use git (no branching) to back up my work and an external hard drive.

  I was hoping to use postscript instead of pdf during the development
process as I might have more control over the app and therefore the
workflow and therefore be more productive and less frustrated.

  This process was so much easier when using Solaris on a Sun pizza
box (30+ years ago).  It worked great on Linux (less than 30 years
ago).  Perhaps the Mac is just too much "locked hood" (can't fiddle
with the engine) and that frustrates this old retired geezer.  I hated
Windows for this same reason; no user control over my environment.  I
guess that's way I like emacs, Perl, Linux, UNIX...

  Anyway...I was trying to simplify my workflow...

Thanks,
Ken Wolcott

On Wed, Aug 3, 2022 at 7:22 AM David Wright <lilylis@lionunicorn.co.uk> wrote:
>
> On Wed 03 Aug 2022 at 09:22:53 (+0200), Jean Abou Samra wrote:
> > > Le 3 août 2022 à 01:24, Kenneth Wolcott <kennethwolcott@gmail.com> a 
> > > écrit :
> > >  I'm trying to simplify my workflow. I think I want to generate
> > > postscript files instead of pdf files when using Lilypond.  I already
> > > know how to do that.  But what I need to know is, on a Mac, how to
> > > display the postscript file from the command line.  I used to do this
> > > all the time a long time ago when I used UNIX and Linux, but homebrew
> > > gs doesn't display the postscript.  I do not want to use preview.
> > >
> > >  This used to be a TRIVIAL thing to do when I was younger, but now I
> > > am old and my brain just isn't what it used to be.
> > >
> > >  I've looked at several man pages and/or info and/or help (lastly
> > > /opt/homebrew/Cellar/ghostscript/9.56.1_1/share/doc/ghostscript/9.56.1/Use.htm)
> > >
> > > Current attempt:
> > >
> > > /opt/homebrew/Cellar/ghostscript/9.56.1_1/bin/gs -sDEVICE=display
> > > ../target/The_Swan.ps
> > > GPL Ghostscript 9.56.1 (2022-04-04)
> > > Copyright (C) 2022 Artifex Software, Inc.  All rights reserved.
> > > This software is supplied under the GNU AGPLv3 and comes with NO WARRANTY:
> > > see the file COPYING for details.
> > > zsh: segmentation fault
> > > /opt/homebrew/Cellar/ghostscript/9.56.1_1/bin/gs -sDEVICE=display
> > >
> > > So, what flags should I be using just to display the postscript?
> >
> > Personally, I’d just have done
> >
> > ps2pdf file.ps
> > open file.pdf
>
> I'd be tempted to do the same. Having put up with gv's interface for
> years, it was a relief when a pdflatex workflow supplanted dvips's.
>
> But another suggestion would be to run LP with 
> -ddelete-intermediate-files='#f'
> in which case you get both a PS and PDF. View one, and rename and
> process the other. The wrinkle is, of course, that Usage states:
>
>   delete-intermediate-files bool
>       If bool is #t, delete the unusable, intermediate .ps files
>       created during compilation
>       Default: #t.
>
> However, I can't see any visual difference between LP's PDF and the
> PDF converted by ps2pdf from the intermediate file. Should I?
> What is meant to make the PS unusable?
>
> > I believe this is actually what some of the modern document viewers do if 
> > you ask them to open a PS file.
> >
> > Bottom line: this may be an XY question. Why do you want to generate 
> > PostScript in the first place?
>
> My first thought, too, especially as the OP writes "I /think/ I want
> to generate postscript files …". But I hope my suggestions above are
> suitably actionable, though not in the sense that word is usually used
> over here. :)
>
> Cheers,
> David.