sybperl-l Archive

From: Michael Peppler <mpeppler at mbay dot net>
Subject: Re: perl and LD_LIBRARY_PATH
Date: Dec 12 1997 10:43PM

Katherine Marsden wrote:
> 
> Hi:
> 
> I am getting an error loading libsybdb.so when I use
> the Sybperl module.
> 
> If I add the location of this file (/usr/local/system10/lib)
> to my LD_LIBRARY_PATH environmental variable, it works.
> I want to avoid this as a requirement for my users,
> so would like to do something like.
> 
> $ENV{LD_LIBRARY_PATH} .= "/usr/local/system10/lib:$ENV{LD_LIBRARY_PATH};
> 
> use Sybase::DBlib;
> 
> This does not work.  How can I have my perl script make this
> addition to LD_LIBRARY_PATH before loading sybase.

The short answer is that it can't.

It is not possible to set LD_LIBRARY_PATH to affect a running process.
You can only affect processes that will be created from this process.

So one solution is to write a small shell wrapper that sets 
LD_LIBRARY_PATH before exec'ing the perl script.

Another (untested) solution would be to do something like:

#!/usr/local/bin/perl

BEGIN {
   if($ENV{LD_LIBRARY_PATH} !~ /sybase/) {
	$ENV{LD_LIBRARY_PATH} .= ":/usr/local/sybase/lib";
         exec $0, @ARGV; 
   }
}

use Sybase::DBlib;

etc...

which might work.

However, it is normally not necessary to have LD_LIBRARY_PATH set
if sybperl is built correctly, unless you move the binary to a new
machine/environement where the Sybase libraries are in a different
location.

BTW this has nothing to do with perl's DynaLoader. It's ld.so
that does the dynamic loading of the Sybase libraries. The DynaLoader
loads the DBlib.so glue code.

Michael
-- 
Michael Peppler       -||-  Data Migrations Inc.
mpeppler@datamig.com  -||-  http://www.mbay.net/~mpeppler