From mboxrd@z Thu Jan  1 00:00:00 1970
X-Msuck: nntp://news.gmane.io/gmane.comp.tex.context/4398
Path: main.gmane.org!not-for-mail
From: Ed L Cashin <ecashin@terry.uga.edu>
Newsgroups: gmane.comp.tex.context
Subject: Re: metapost not invoked? mpgraph.1 not created
Date: 15 Mar 2001 14:45:12 -0500
Sender: owner-ntg-context@let.uu.nl
Message-ID: <m3k85qsto7.fsf@terry.uga.edu>
References: <m37l2l4az8.fsf@coe.uga.edu> <Your
	<3.0.6.32.20010219172259.0157a600@server-1>
	<3.0.6.32.20010220125344.01cc87b0@server-1>
	<m37l2l4az8.fsf@coe.uga.edu>
	<3.0.6.32.20010220174002.00afa980@server-1>
	<86elvzp9t7.fsf@office.admaster.pl>
NNTP-Posting-Host: coloc-standby.netfonds.no
Mime-Version: 1.0
Content-Type: text/plain; charset=us-ascii
X-Trace: main.gmane.org 1035395069 25452 80.91.224.250 (23 Oct 2002 17:44:29 GMT)
X-Complaints-To: usenet@main.gmane.org
NNTP-Posting-Date: Wed, 23 Oct 2002 17:44:29 +0000 (UTC)
Cc: Hans Hagen <pragma@wxs.nl>, Marc van Dongen <dongen@cs.ucc.ie>,
        Patrick Gundlach <gundlach@irb.cs.uni-dortmund.de>,
        ConTeXt <ntg-context@ntg.nl>
Original-To: Slawek Zak <zaks@prioris.mini.pw.edu.pl>
In-Reply-To: <86elvzp9t7.fsf@office.admaster.pl>
Xref: main.gmane.org gmane.comp.tex.context:4398
X-Report-Spam: http://spam.gmane.org/gmane.comp.tex.context:4398

Slawek Zak <zaks@prioris.mini.pw.edu.pl> writes:

...
> Which makes perl try to run the script on UNIX systems without
> checking if it's executable (texutil was -x in my case) and, which is
> more problematic, doesn't check for possible execution errors. I've
> proposed some time ago to change the call to something like:
> 
>   ...
>   if (! -x $ScriptName) {
>         die("Nonexecutable script, fix the permisions for $ScriptName\n");
>   } else {
>          system ("$ScriptName $Options") or die $!;
>   }
>   ...
> 
> What do you think?

I think it's not necessary to be that specific, since perl knows what
the last error was (it's in the $! variable), and you're limiting
yourself to just one error.  

If the $ScriptName wasn't there at all, for example, your error
message would be misleading.  Instead, let things take care of
themselves:

  $ cp /bin/ls .
  $ chmod 644 ls
  $ perl -e 'die "Error: could not run ls: $!" if system "./ls"'
  Error: could not run ls: Permission denied at -e line 1.

... and anyone who's familiar with UN*X has seen "Permission denied"
when the permission to execute is not set.

-- 
--Ed Cashin                   PGP public key:
  ecashin@terry.uga.edu       http://www.terry.uga.edu/~ecashin/pgp/