use warnings;
use strict;

my $NB_ORA_CINC;
my $NB_ORA_CLIENT;
my @NB_VAR_LIST=("NB_ORA_CINC", "NB_ORA_CLIENT");
my $NB_VAR;

$ENV{NB_ORA_CLIENT} = 'client01';
$ENV{NB_ORA_CINC} = 1;

foreach $NB_VAR ( @NB_VAR_LIST ) {
   if ( defined $ENV{$NB_VAR} ) {
      print "Variable $NB_VAR is $ENV{${NB_VAR}}\n";
      eval("\$${NB_VAR} = $ENV{${NB_VAR}}");
      warn $@ if $@;
   }
}

if ( defined $NB_ORA_CINC )   { print "\$NB_ORA_CINC   is $NB_ORA_CINC\n"; }
if ( defined $NB_ORA_CLIENT ) { print "\$NB_ORA_CLIENT is $NB_ORA_CLIENT\n"; }

__END__

Variable NB_ORA_CINC is 1
Variable NB_ORA_CLIENT is client01
Bareword "client01" not allowed while "strict subs" in use at (eval 2) line 1.
$NB_ORA_CINC   is 1