Re: metapost not invoked? mpgraph.1 not created

[Ed L Cashin <ecashin@terry.uga.edu>]

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/