Here's a more flexible way, which will work even if the environment file contains shell commands:

#!/usr/bin/perl

print "Starting...\n";

use constant ENVSCRIPT => '/etc/profiles/bashrc.ora.v.10';
if (!$ENV{ORACLE_HOME} && !$ENV{SKIP_ENVSCRIPT})
{
  $ENV{SKIP_ENVSCRIPT}=1;
  exec("/bin/sh -c '. @{[ENVSCRIPT]}; exec $0'");
}

print "ORACLE_HOME=$ENV{ORACLE_HOME}\n";
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If $ENV{ORACLE_HOME} is unset, it runs a copy of the shell to first source the environment file, then re-execute your script. $ENV{SKIP_ENVSCRIPT} keeps this from looping if there are problems.

One caveat is that if the script is run like perl your_script.pl the exec may not work. If that's how you normally call your script, you should be able to adjust the shell line to take that into account.