runMPgraphicstrue produces undefined figure

runMPgraphicstrue produces undefined figure

[Sanjoy Mahajan]

I'm playing with simple files in order to learn metafun.  The following
small example produces an undefined figure.  It illustrates either a
context problem or, more likely, a confusion on my part.

================= cut here ===========================================
\runMPgraphicstrue
\starttext

\startreusableMPgraphic{a}
fill fullcircle scaled 2cm;
\stopreusableMPgraphic

\placefigure[here,none]{}{\reuseMPgraphic{a}}
\input tufte
\stoptext
================= cut here ===========================================

The figure is a square saying 'undefined'.  Taking away the
\runMPgraphicstrue line produces the expected filled circle.

I use a web2c distribution (linux) with

  context version 2006.08.08 21:51,
  TeXExec | version 6.2.0 - 1997-2006 - PRAGMA ADE/POD

It passes the write18 test given in the metafun-s.pdf manual (p.214 of
the PDF file).

-Sanjoy

`A society of sheep must in time beget a government of wolves.'
   - Bertrand de Jouvenal

Re: runMPgraphicstrue produces undefined figure

[Aditya Mahajan]

On Tue, 12 Sep 2006, Sanjoy Mahajan wrote:

> I'm playing with simple files in order to learn metafun.  The following
> small example produces an undefined figure.  It illustrates either a
> context problem or, more likely, a confusion on my part.
>
> ================= cut here ===========================================
> \runMPgraphicstrue
> \starttext
>
> \startreusableMPgraphic{a}
> fill fullcircle scaled 2cm;
> \stopreusableMPgraphic
>
> \placefigure[here,none]{}{\reuseMPgraphic{a}}
> \input tufte
> \stoptext
> ================= cut here ===========================================
>
> The figure is a square saying 'undefined'.  Taking away the
> \runMPgraphicstrue line produces the expected filled circle.
>
> I use a web2c distribution (linux) with
>
>  context version 2006.08.08 21:51,
>  TeXExec | version 6.2.0 - 1997-2006 - PRAGMA ADE/POD

Strange... It works fine here with

ConTeXt  ver: 2006.09.10 13:33 MK II  fmt: 2006.9.10  int: 
english/english

Normally, runMPgraphics is set to true in one of the files, so you do 
not need to set it to true. I have no idea why you should be getting 
'undefined'. Check your log file for

systems         : system commands are enabled

and

system(mpost  -progname=metafun -mem=metafun mptest-mpgraph)...executed.


Aditya

Re: runMPgraphicstrue produces undefined figure

[Sanjoy Mahajan]

> Check your log file for
>
> systems         : system commands are enabled

Thanks, that was the problem.  It was saying 'disabled' instead.  The
fix was to change /etc/texmf/texmf.cnf to enable write18.  The
shell_escape line has to be set to 't' rather than 'f', i.e.:

 shell_escape = t

Actually, on my system (Ubuntu, a Debian derivative), changing the
texmf.cnf file directly is not a good idea.  Instead one should change
the same line in /etc/texmf/texmf.d/95NonPath.cnf and then run
'update-texmf' as root to generate the texmf.cnf file.

Warning: If you've enabled 'shell_escape', then don't run *TeX on
untrusted files, in case they do anything malicious like 'rm -fr /'.

Also now I see how I got fooled into thinking that write18 was already
enabled.  The one-line tex file from metafun-s.pdf contains
\immediate\write18{echo It works}.  When run it produces an "It works"
whether or not write18 is enabled.  If disabled:

(./3.tex
echo It works
 )

which made me think that all was okay.  If enabled you get this:

 \write18 enabled.
(./3.texIt works
 )

-Sanjoy

`Never underestimate the evil of which men of power are capable.'
         --Bertrand Russell, _War Crimes in Vietnam_, chapter 1.

Re: runMPgraphicstrue produces undefined figure

[Hans Hagen]

Sanjoy Mahajan wrote:
> Actually, on my system (Ubuntu, a Debian derivative), changing the
> texmf.cnf file directly is not a good idea.  Instead one should change
> the same line in /etc/texmf/texmf.d/95NonPath.cnf and then run
> 'update-texmf' as root to generate the texmf.cnf file.
>   
incredible (probably a copy of texmf.cnf in your local tree also works 
ok; in that case: clean up the file a bit and things run faster too)
> Warning: If you've enabled 'shell_escape', then don't run *TeX on
> untrusted files, in case they do anything malicious like 'rm -fr /'.
>   
well, opening files and overwriting them can be done anyway

Hans


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Re: runMPgraphicstrue produces undefined figure

[Sanjoy Mahajan]

Hans Hagen wrote:
> Sanjoy Mahajan wrote:
> > Actually, on my system (Ubuntu, a Debian derivative), changing the
> > texmf.cnf file directly is not a good idea.  Instead one should change
> > the same line in /etc/texmf/texmf.d/95NonPath.cnf and then run
> > 'update-texmf' as root to generate the texmf.cnf file.
> >   
> incredible (probably a copy of texmf.cnf in your local tree also works 
> ok; in that case: clean up the file a bit and things run faster too)

Yeah, it's a pain but it does have one justificaiton.  This texmf.cnf
system is easy for computers to update, although not for people.  The
idea is that new tex-related packages add options by placing the
options in a file in /etc/texmf/texmf.d/ and then running update-texmf
to combine the configlets into the One File to rule them all.

The diversity of configuration systems and options across different
tex installations is a big pain, makes it hard to create
cross-platform software.

-Sanjoy

`Never underestimate the evil of which men of power are capable.'
         --Bertrand Russell, _War Crimes in Vietnam_, chapter 1.

Re: runMPgraphicstrue produces undefined figure

[Sanjoy Mahajan]

Hans Hagen wrote:
> well, opening files and overwriting them can be done anyway

That's true.  Though the default teTeX setup seems to be (from
texmf.cnf):

  % Allow TeX \openin, \openout, or \input on filenames starting with `.'
  % (e.g., .rhosts) or outside the current tree (e.g., /etc/passwd)?
  % a (any)        : any file can be opened.
  % r (restricted) : disallow opening "dotfiles".
  % p (paranoid)   : as 'r' and disallow going to parent directories, and
  %                  restrict absolute paths to be under $TEXMFOUTPUT.
  openout_any = p
  openin_any = a

So you can read any file but you cannot write any file.  Seems
sensible.

-Sanjoy

`Never underestimate the evil of which men of power are capable.'
         --Bertrand Russell, _War Crimes in Vietnam_, chapter 1.